/*
Copyright (c) 2007, Yahoo! Inc. All rights reserved.
Code licensed under the BSD License:
http://developer.yahoo.net/yui/license.txt
version: 2.2.0
*/
/**
 * The DataTable widget provides a progressively enhanced DHTML control for
 * displaying tabular data across A-grade browsers.
 *
 * @module datatable
 * @requires yahoo, dom, event, datasource
 * @optional dragdrop
 * @title DataTable Widget
 * @beta
 */

/****************************************************************************/
/****************************************************************************/
/****************************************************************************/

/**
 * DataTable class for the YUI DataTable widget.
 *
 * @class DataTable
 * @uses YAHOO.util.EventProvider
 * @constructor
 * @param elContainer {HTMLElement} Container element for the TABLE.
 * @param oColumnSet {YAHOO.widget.ColumnSet} ColumnSet instance.
 * @param oDataSource {YAHOO.util.DataSource} DataSource instance.
 * @param oConfigs {object} (optional) Object literal of configuration values.
 */
YAHOO.widget.DataTable = function(elContainer,oColumnSet,oDataSource,oConfigs) {
    // Internal vars
    var i;
    this._nIndex = YAHOO.widget.DataTable._nCount;
    this._sName = "instance" + this._nIndex;
    this.id = "yui-dt"+this._nIndex;

    // Validate configs
    if(typeof oConfigs == "object") {
        for(var sConfig in oConfigs) {
            this[sConfig] = oConfigs[sConfig];
        }
    }

    // Validate DataSource
    if(oDataSource) {
        if(oDataSource instanceof YAHOO.util.DataSource) {
            this.dataSource = oDataSource;
        }
        else {
            YAHOO.log("Invalid DataSource", "warn", this.toString());
        }
    }

    // Validate ColumnSet
    if(oColumnSet && (oColumnSet instanceof YAHOO.widget.ColumnSet)) {
        this._oColumnSet = oColumnSet;
    }
    else {
        YAHOO.log("Could not instantiate DataTable due to an invalid ColumnSet", "error", this.toString());
        return;
    }
    
    // Create RecordSet
    this._oRecordSet = new YAHOO.widget.RecordSet();

    // Validate HTML Element
    elContainer = YAHOO.util.Dom.get(elContainer);
    if(elContainer && elContainer.tagName && (elContainer.tagName.toLowerCase() == "div")) {
        this._elContainer = elContainer;
        // Peek in container child nodes to see if TABLE already exists
        var elTable = null;
        if(elContainer.hasChildNodes()) {
            var children = elContainer.childNodes;
            for(i=0; i<children.length; i++) {
                if(children[i].tagName && children[i].tagName.toLowerCase() == "table") {
                    elTable = children[i];
                    break;
                }
            }
        }

        // Progressively enhance an existing table from markup...
        // while using the markup as the source of data
        if(elTable && !this.dataSource) {
            // Fill RecordSet with data parsed out of table
            var aRecords = [];

            // Iterate through each TBODY
            for(i=0; i<elTable.tBodies.length; i++) {
                var elBody = elTable.tBodies[i];

                // Iterate through each TR
                for(var j=0; j<elBody.rows.length; j++) {
                    var elRow = elBody.rows[j];
                    var oRecord = {};

                    // Iterate through each TD
                    for(var k=0; k<elRow.cells.length; k++) {

                        //var elCell = elRow.cells[l];
                        //elCell.id = this.id+"-bdrow"+k+"-cell"+l;
                        //TODO: can we parse a column with null key?
                        oRecord[oColumnSet.keys[k].key] = oColumnSet.keys[k].parse(elRow.cells[k].innerHTML);
                    }
                    aRecords.push(oRecord);
                }
            }
            
            this._initTable();
            
            var ok = this.doBeforeLoadData(aRecords);
            if(ok) {
                this._oRecordSet.addRecords(aRecords);
                this.paginateRows();
            }
        }
        // Create markup from scratch using the provided DataSource
        else if(this.dataSource) {
                this._initTable();
                // Send out for data in an asynchronous request
                oDataSource.sendRequest(this.initialRequest, this.onDataReturnPaginateRows, this);
        }
        // Else there is no data
        else {
            this._initTable();
            this.showEmptyMessage();
        }
    }
    // Container element not found in document
    else {
        YAHOO.log("Could not instantiate DataTable due to an invalid container element", "error", this.toString());
        return;
    }

    // Set up sort
    this.subscribe("headCellClickEvent",this.onEventSortColumn);

    // Set up context menu
    //TODO: does trigger have to exist? can trigger be TBODY rather than rows?
    if(this.contextMenu && this.contextMenuOptions) {
        this.contextMenu = new YAHOO.widget.ContextMenu(this.id+"-cm", { trigger: this._elBody.rows } );
        this.contextMenu.addItem("delete item");
        this.contextMenu.render(document.body);
    }

    // Set up event model
    elTable = this._elTable;
    /////////////////////////////////////////////////////////////////////////////
    //
    // DOM Events
    //
    /////////////////////////////////////////////////////////////////////////////
    //YAHOO.util.Event.addListener(this._elContainer, "focus", this._onFocus, this);
    YAHOO.util.Event.addListener(elTable, "click", this._onClick, this);
    YAHOO.util.Event.addListener(elTable, "dblclick", this._onDoubleclick, this);
    YAHOO.util.Event.addListener(elTable, "mouseout", this._onMouseout, this);
    YAHOO.util.Event.addListener(elTable, "mouseover", this._onMouseover, this);
    YAHOO.util.Event.addListener(elTable, "mousedown", this._onMousedown, this);
    //YAHOO.util.Event.addListener(elTable, "mouseup", this._onMouseup, this);
    //YAHOO.util.Event.addListener(elTable, "mousemove", this._onMousemove, this);
    YAHOO.util.Event.addListener(elTable, "keydown", this._onKeydown, this);
    YAHOO.util.Event.addListener(elTable, "keypress", this._onKeypress, this);
    YAHOO.util.Event.addListener(document, "keyup", this._onDocumentKeyup, this);
    YAHOO.util.Event.addListener(elTable, "keyup", this._onKeyup, this);
    //YAHOO.util.Event.addListener(elTable, "focus", this._onFocus, this);
    YAHOO.util.Event.addListener(elTable, "blur", this._onBlur, this);

    /////////////////////////////////////////////////////////////////////////////
    //
    // Custom Events
    //
    /////////////////////////////////////////////////////////////////////////////

    /**
     * Fired when a mouseover occurs on a TD element.
     *
     * @event cellMouseoverEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The TD element.
     */
    this.createEvent("cellMouseoverEvent");

    /**
     * Fired when a mouseout occurs on a TD element.
     *
     * @event cellMouseoutEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The TD element.
     */
    this.createEvent("cellMouseoutEvent");

    /**
     * Fired when a TH cell element is mouseover.
     *
     * @event headCellMouseoverEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The TH element.
     *
     */
    this.createEvent("headCellMouseoverEvent");

    /**
     * Fired when a TH cell element is mouseout.
     *
     * @event headCellMouseoutEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The TH element.
     *
     */
    this.createEvent("headCellMouseoutEvent");

    /**
     * Fired when a TABLE element is mouseover.
     *
     * @event tableMouseoverEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The TABLE element.
     *
     */
    this.createEvent("tableMouseoverEvent");

    /**
     * Fired when a TABLE element is mouseout.
     *
     * @event tableMouseoutEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The TABLE element.
     *
     */
    this.createEvent("tableMouseoutEvent");

    /**
     * Fired when a mousedown occurs on a TD element.
     *
     * @event cellMousedownEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The TD element.
     */
    this.createEvent("cellMousedownEvent");

    /**
     * Fired when a TH cell element is mousedown.
     *
     * @event headCellMousedownEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The TH element.
     */
    this.createEvent("headCellMousedownEvent");

    /**
     * Fired when a TABLE element is mousedown.
     *
     * @event tableMousedownEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The TABLE element.
     *
     */
    this.createEvent("tableMousedownEvent");

    /**
     * Fired when a CHECKBOX element is clicked.
     *
     * @event checkboxClickEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The CHECKBOX element.
     */
    this.checkboxClickEvent = this.createEvent("checkboxClickEvent");
    //this.checkboxClickEvent.subscribeEvent.subscribe(this._registerEvent,{type:"checkboxClickEvent"},this);

    /**
     * Fired when a RADIO element is clicked.
     *
     * @event radioClickEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The RADIO element.
     */
    this.createEvent("radioClickEvent");
    
    /**
     * Fired when a TD element is clicked.
     *
     * @event cellClickEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The TD element.
     */
    this.createEvent("cellClickEvent");

    /**
     * Fired when a TH cell element is clicked.
     *
     * @event headCellClickEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The TH element.
     */
    this.createEvent("headCellClickEvent");

    /**
     * Fired when a TABLE element is clicked.
     *
     * @event tableClickEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The TABLE element.
     *
     */
    this.createEvent("tableClickEvent");

    /**
     * Fired when a TD element is doubleclicked.
     *
     * @event cellDoubleclickEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The TD element.
     */
    this.createEvent("cellDoubleclickEvent");

    /**
     * Fired when a TH cell element is doubleclicked.
     *
     * @event headCellDoubleclickEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The TH element.
     */
    this.createEvent("headCellDoubleclickEvent");

    /**
     * Fired when a TABLE element is doubleclicked.
     *
     * @event tableDoubleclickEvent
     * @param oArgs.event {HTMLEvent} The event object.
     * @param oArgs.target {HTMLElement} The TABLE element.
     *
     */
    this.createEvent("tableDoubleclickEvent");

    /**
     * Fired when a column is sorted.
     *
     * @event columnSortEvent
     * @param oArgs.column {YAHOO.widget.Column} The Column instance.
     * @param oArgs.dir {String} Sort direction "asc" or "desc".
     */
    this.createEvent("columnSortEvent");

    /**
     * Fired when an editor is activated.
     *
     * @event editorShowEvent
     * @param oArgs.target {HTMLElement} The TD element.
     * @param oArgs.column {YAHOO.widget.Column} The Column instance.
     */
    this.createEvent("editorShowEvent");


    /**
     * Fired when a cell is edited.
     *
     * @event cellEditEvent
     * @param oArgs.target {HTMLElement} The TD element.
     * @param oArgs.newData {Object} New data value.
     * @param oArgs.oldData {Object} Old data value.
     */
    this.createEvent("cellEditEvent");

    /**
     * Fired when a column is resized.
     *
     * @event columnResizeEvent
     * @param oArgs.target {HTMLElement} The TH element.
     */
    this.createEvent("columnResizeEvent");

    /**
     * Fired when DataTable instance is first initialized.
     *
     * @event tableInitEvent
     */
    this.createEvent("tableInitEvent");

    /**
     * Fired when DataTable instance is focused.
     *
     * @event tableFocusEvent
     */
    this.createEvent("tableFocusEvent");

    /**
     * Fired when data is returned from DataSource.
     *
     * @event dataReturnEvent
     * @param oArgs.request {String} Original request.
     * @param oArgs.response {Object} Response object.
     */
    this.createEvent("dataReturnEvent");

    /**
     * Fired when DataTable is paginated.
     *
     * @event paginateEvent
     */
    this.createEvent("paginateEvent");

    /**
     * Fired when a TD element is formatted.
     *
     * @event cellFormatEvent
     * @param oArgs.el {HTMLElement} Reference to the TD element.
     */
    this.createEvent("cellFormatEvent");

    /**
     * Fired when an element is selected.
     *
     * @event selectEvent
     * @param oArgs.els {Array} An array of the selected element(s).
     */
    this.createEvent("selectEvent");

    /**
     * Fired when an element is unselected.
     *
     * @event unselectEvent
     * @param oArgs.els {Array} An array of the unselected element(s).
     */
    this.createEvent("unselectEvent");

    /**
     * Fired when an element is highlighted.
     *
     * @event highlightEvent
     * @param oArgs.els {Array} An array of the highlighted element(s).
     */
    this.createEvent("highlightEvent");

    /**
     * Fired when an element is unhighlighted.
     *
     * @event unhighlightEvent
     * @param oArgs.els {Array} An array of the unhighlighted element(s).
     */
    this.createEvent("unhighlightEvent");
    
    /**
     * Fired when one or more TR elements are deleted.
     *
     * @event rowDeleteEvent
     * @param oArgs.rowIndexes {Array} The indexes of the deleted rows.
     */
    this.createEvent("rowDeleteEvent");
    this.subscribe("rowDeleteEvent", this._onRowDelete);
    
    /**
     * Fired when one or more TR elements are appended.
     *
     * @event rowAppendEvent
     * @param oArgs.rowIds {Array} The IDs of the appended rows.
     */
    this.createEvent("rowAppendEvent");

    /**
     * Fired when a Record is updated in the RecordSet.
     *
     * @event recordSetUpdateEvent
     * @param oArgs.record {YAHOO.widget.Record} The Record instance.
     * @param oArgs.key {String} The Record key.
     * @param oArgs.newData {Object} New data.
     * @param oArgs.oldData {Object} New data.
     */
    this.createEvent("recordSetUpdateEvent");
    this._oRecordSet.subscribe("recordUpdateEvent", this._onRecordUpdate, this, true);
    
    
    YAHOO.widget.DataTable._nCount++;
    YAHOO.log("DataTable initialized", "info", this.toString());
    this.fireEvent("tableInitEvent");
};

if(YAHOO.util.EventProvider) {
    YAHOO.augment(YAHOO.widget.DataTable, YAHOO.util.EventProvider);
}
else {
    YAHOO.log("Missing dependency: YAHOO.util.EventProvider","error",this.toString());
}

/////////////////////////////////////////////////////////////////////////////
//
// Public constants
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Class name assigned to TBODY element that holds data rows.
 *
 * @property CLASS_BODY
 * @type String
 * @static
 * @final
 * @default "yui-dt-body"
 */
YAHOO.widget.DataTable.CLASS_BODY = "yui-dt-body";

/**
 * Class name assigned to container element within THEAD.
 *
 * @property CLASS_HEADCONTAINER
 * @type String
 * @static
 * @final
 */
YAHOO.widget.DataTable.CLASS_HEADCONTAINER = "yui-dt-headcontainer";

/**
 * Class name assigned to resizer handle element within THEAD.
 *
 * @property CLASS_HEADRESIZER
 * @type String
 * @static
 * @final
 * @default "yui-dt-headresizer"
 */
YAHOO.widget.DataTable.CLASS_HEADRESIZER = "yui-dt-headresizer";

/**
 * Class name assigned to text displayed within THEAD.
 *
 * @property CLASS_HEADTEXT
 * @type String
 * @static
 * @final
 * @default "yui-dt-headtext"
 */
YAHOO.widget.DataTable.CLASS_HEADTEXT = "yui-dt-headtext";

/**
 * Class name assigned to even TR elements.
 *
 * @property CLASS_EVEN
 * @type String
 * @static
 * @final
 * @default "yui-dt-even
 */
YAHOO.widget.DataTable.CLASS_EVEN = "yui-dt-even";

/**
 * Class name assigned to odd TR elements.
 *
 * @property CLASS_ODD
 * @type String
 * @static
 * @final
 * @default "yui-dt-odd"
 */
YAHOO.widget.DataTable.CLASS_ODD = "yui-dt-odd";

/**
 * Class name assigned to first td elements.
 *
 * @property CLASS_FIRST_COLUMN
 * @type String
 * @static
 * @final
 * @default "yui-dt-first-column"
 */
YAHOO.widget.DataTable.CLASS_FIRST_COLUMN = "yui-dt-first-column";

/**
 * Class name assigned to last td elements.
 *
 * @property CLASS_LAST_COLUMN
 * @type String
 * @static
 * @final
 * @default "yui-dt-last-column"
 */
YAHOO.widget.DataTable.CLASS_LAST_COLUMN = "yui-dt-last-column";

/**
 * Class name assigned to table element.
 *
 * @property CLASS_DATA_TABLE
 * @type String
 * @static
 * @final
 * @default "yui-dt"
 */
YAHOO.widget.DataTable.CLASS_DATA_TABLE = "yui-dt";

/**
 * Class name assigned to empty elements.
 *
 * @property CLASS_EMPTY
 * @type String
 * @static
 * @final
 * @default "yui-dt-empty"
 */
YAHOO.widget.DataTable.CLASS_EMPTY = "yui-dt-empty";

/**
 * Class name assigned to loading message.
 *
 * @property CLASS_LOADING
 * @type String
 * @static
 * @final
 * @default "yui-dt-loading"
 */
YAHOO.widget.DataTable.CLASS_LOADING = "yui-dt-loading";

/**
 * Class name assigned to selected elements.
 *
 * @property CLASS_SELECTED
 * @type String
 * @static
 * @final
 * @default "yui-dt-selected"
 */
YAHOO.widget.DataTable.CLASS_SELECTED = "yui-dt-selected";

/**
 * Class name assigned to highlighted element.
 *
 * @property CLASS_HIGHLIGHT
 * @type String
 * @static
 * @final
 * @default "yui-dt-highlight"
 */
YAHOO.widget.DataTable.CLASS_HIGHLIGHT = "yui-dt-highlight";

/**
 * Class name assigned to certain elements of a scrollable DataTable.
 *
 * @property CLASS_SCROLLABLE
 * @type String
 * @static
 * @final
 * @default "yui-dt-scrollable"
 */
YAHOO.widget.DataTable.CLASS_SCROLLABLE = "yui-dt-scrollable";

/**
 * Class name assigned to column headers of sortable Columns.
 *
 * @property CLASS_SORTABLE
 * @type String
 * @static
 * @final
 * @default "yui-dt-sortable"
 */
YAHOO.widget.DataTable.CLASS_SORTABLE = "yui-dt-sortable";

/**
 * Class name assigned to column headers when sorted in ascending order.
 *
 * @property CLASS_SORTEDBYASC
 * @type String
 * @static
 * @final
 * @default "yui-dt-sortedbyasc"
 */
YAHOO.widget.DataTable.CLASS_SORTEDBYASC = "yui-dt-sortedbyasc";

/**
 * Class name assigned to column headers when sorted in descending order.
 *
 * @property CLASS_SORTEDBYDESC
 * @type String
 * @static
 * @final
 * @default "yui-dt-sortedbydesc"
 */
YAHOO.widget.DataTable.CLASS_SORTEDBYDESC = "yui-dt-sortedbydesc";

/**
 * Class name assigned to the pagination link "&lt;&lt;".
 *
 * @property CLASS_FIRSTLINK
 * @type String
 * @static
 * @final
 * @default "yui-dt-firstlink"
 */
YAHOO.widget.DataTable.CLASS_FIRSTLINK = "yui-dt-firstlink";

/**
 * Class name assigned to the pagination link "&lt;&lt;" when it is disabled.
 *
 * @property CLASS_FIRSTPAGE
 * @type String
 * @static
 * @final
 * @default "yui-dt-firstpage"
 */
YAHOO.widget.DataTable.CLASS_FIRSTPAGE = "yui-dt-firstpage";

/**
 * Class name assigned to the pagination link "&gt;&gt;".
 *
 * @property CLASS_LASTLINK
 * @type String
 * @static
 * @final
 * @default "yui-dt-lastlink"
 */
YAHOO.widget.DataTable.CLASS_LASTLINK = "yui-dt-lastlink";

/**
 * Class name assigned to the pagination link "&gt;&gt;" when it is disabled.
 *
 * @property CLASS_LASTPAGE
 * @type String
 * @static
 * @final
 * @default "yui-dt-lastpage"
 */
YAHOO.widget.DataTable.CLASS_LASTPAGE = "yui-dt-lastpage";

/**
 * Class name assigned to the pagination link "&lt;".
 *
 * @property CLASS_PREVLINK
 * @type String
 * @static
 * @final
 * @default "yui-dt-prevlink"
 */
YAHOO.widget.DataTable.CLASS_PREVLINK = "yui-dt-prevlink";

/**
 * Class name assigned to the pagination link "&lt;" when it is disabled.
 *
 * @property CLASS_PREVPAGE
 * @type String
 * @static
 * @final
 * @default "yui-dt-prevpage"
 */
YAHOO.widget.DataTable.CLASS_PREVPAGE = "yui-dt-prevpage";

/**
 * Class name assigned to the pagination link "&gt;".
 *
 * @property CLASS_NEXTLINK
 * @type String
 * @static
 * @final
 * @default "yui-dt-nextlink"
 */
YAHOO.widget.DataTable.CLASS_NEXTLINK = "yui-dt-nextlink";

/**
 * Class name assigned to the pagination link "&gt;" when it is disabled.
 *
 * @property CLASS_NEXTPAGE
 * @type String
 * @static
 * @final
 * @default "yui-dt-nextpage"
 */
YAHOO.widget.DataTable.CLASS_NEXTPAGE = "yui-dt-nextpage";


/**
 * Class name assigned to pagination links to specific page numbers.
 *
 * @property CLASS_PAGELINK
 * @type String
 * @static
 * @final
 * @default "yui-dt-pagelink"
 */
YAHOO.widget.DataTable.CLASS_PAGELINK = "yui-dt-pagelink";

/**
 * Class name assigned to pagination links for specific page numbers that are disabled.
 *
 * @property CLASS_CURRENTPAGE
 * @type String
 * @static
 * @final
 * @default "yui-dt-currentpage"
 */
YAHOO.widget.DataTable.CLASS_CURRENTPAGE = "yui-dt-currentpage";

/**
 * Class name assigned to the pagination SELECT element.
 *
 * @property CLASS_PAGESELECT
 * @type String
 * @static
 * @final
 * @default "yui-dt-pageselect"
 */
YAHOO.widget.DataTable.CLASS_PAGESELECT = "yui-dt-pageselect";

/**
 * Class name assigned to the pagination links container element.
 *
 * @property CLASS_PAGELINKS
 * @type String
 * @static
 * @final
 * @default "yui-dt-pagelinks"
 */
YAHOO.widget.DataTable.CLASS_PAGELINKS = "yui-dt-pagelinks";

/**
 * Class name assigned to editable TD elements.
 *
 * @property CLASS_EDITABLE
 * @type String
 * @static
 * @final
 * @default "yui-dt-editable"
 */
YAHOO.widget.DataTable.CLASS_EDITABLE = "yui-dt-editable";

/**
 * Class name assigned to TD elements of type "checkbox".
 *
 * @property CLASS_CHECKBOX
 * @type String
 * @static
 * @final
 * @default "yui-dt-checkbox"
 */
YAHOO.widget.DataTable.CLASS_CHECKBOX = "yui-dt-checkbox";

/**
 * Class name assigned to TD elements of type "currency".
 *
 * @property CLASS_CURRENCY
 * @type String
 * @static
 * @final
 * @default "yui-dt-currency"
 */
YAHOO.widget.DataTable.CLASS_CURRENCY = "yui-dt-currency";

/**
 * Class name assigned to TD elements of type "date".
 *
 * @property CLASS_DATE
 * @type String
 * @static
 * @final
 * @default "yui-dt-date"
 */
YAHOO.widget.DataTable.CLASS_DATE = "yui-dt-date";

/**
 * Class name assigned to TD elements of type "email".
 *
 * @property CLASS_EMAIL
 * @type String
 * @static
 * @final
 * @default "yui-dt-email"
 */
YAHOO.widget.DataTable.CLASS_EMAIL = "yui-dt-email";

/**
 * Class name assigned to TD elements of type "link".
 *
 * @property CLASS_LINK
 * @type String
 * @static
 * @final
 * @default "yui-dt-link"
 */
YAHOO.widget.DataTable.CLASS_LINK = "yui-dt-link";

/**
 * Class name assigned to TD elements of type "number".
 *
 * @property CLASS_NUMBER
 * @type String
 * @static
 * @final
 * @default "yui-dt-number"
 */
YAHOO.widget.DataTable.CLASS_NUMBER = "yui-dt-number";

/**
 * Class name assigned to TD elements of type "string".
 *
 * @property CLASS_STRING
 * @type String
 * @static
 * @final
 * @default "yui-dt-string"
 */
YAHOO.widget.DataTable.CLASS_STRING = "yui-dt-string";

/**
 * Message to display if DataTable has no data.
 *
 * @property MSG_EMPTY
 * @type String
 * @static
 * @final
 * @default "No records found."
 */
YAHOO.widget.DataTable.MSG_EMPTY = "No records found.";

/**
 * Message to display while DataTable is loading data.
 *
 * @property MSG_LOADING
 * @type String
 * @static
 * @final
 * @default "Loading data..."
 */
YAHOO.widget.DataTable.MSG_LOADING = "Loading data...";

/////////////////////////////////////////////////////////////////////////////
//
// Private member variables
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Internal class variable to index multiple DataTable instances.
 *
 * @property _nCount
 * @type Number
 * @private
 * @static
 */
YAHOO.widget.DataTable._nCount = 0;

/**
 * Instance index.
 *
 * @property _nIndex
 * @type Number
 * @private
 */
YAHOO.widget.DataTable.prototype._nIndex = null;

/**
 * Unique instance name.
 *
 * @property _sName
 * @type String
 * @private
 */
YAHOO.widget.DataTable.prototype._sName = null;

//TODO: convert these to public members

/**
 * Container element reference. Is null unless the TABLE is built from scratch into the
 * provided container.
 *
 * @property _elContainer
 * @type HTMLElement
 * @private
 */
YAHOO.widget.DataTable.prototype._elContainer = null;

/**
 * TABLE element reference.
 *
 * @property _elTable
 * @type HTMLElement
 * @private
 */
YAHOO.widget.DataTable.prototype._elTable = null;

/**
 * TBODY element reference.
 *
 * @property _elBody
 * @type HTMLElement
 * @private
 */
YAHOO.widget.DataTable.prototype._elBody = null;

/**
 * ColumnSet instance.
 *
 * @property _oColumnSet
 * @type YAHOO.widget.ColumnSet
 * @private
 */
YAHOO.widget.DataTable.prototype._oColumnSet = null;

/**
 * RecordSet instance.
 *
 * @property _oRecordSet
 * @type YAHOO.widget.RecordSet
 * @private
 */
YAHOO.widget.DataTable.prototype._oRecordSet = null;

/**
 * Array of Records that are in the selected state.
 *
 * @property _aSelectedRecords
 * @type YAHOO.widget.Record[]
 * @private
 */
YAHOO.widget.DataTable.prototype._aSelectedRecords = null;

/**
 * Internal variable to track whether widget has focus.
 *
 * @property _bFocused
 * @type Boolean
 * @private
 */
YAHOO.widget.DataTable.prototype._bFocused = false;

/**
 * Total number of pages, calculated on the fly.
 *
 * @property _totalPages
 * @type Number
 * @private
 */
YAHOO.widget.DataTable.prototype._totalPages = null;


/////////////////////////////////////////////////////////////////////////////
//
// Private methods
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Creates HTML markup for TABLE, THEAD, TBODY.
 *
 * @method _initTable
 * @private
 */
YAHOO.widget.DataTable.prototype._initTable = function() {
    // Clear the container
    this._elContainer.innerHTML = "";

    // Set up scrolling
    if(this.scrollable) {
        //TODO: conf height
        YAHOO.util.Dom.addClass(this._elContainer,YAHOO.widget.DataTable.CLASS_SCROLLABLE);
    }

    // Create TABLE
    this._elTable = this._elContainer.appendChild(document.createElement("table"));
    var elTable = this._elTable;
    //Add an id for styling
    elTable.id = this.id;
    //Add a class for styling
    YAHOO.util.Dom.addClass(elTable, YAHOO.widget.DataTable.CLASS_DATA_TABLE);

    elTable.tabIndex = 0;

    // Create SUMMARY, if applicable
    if(this.summary) {
        elTable.summary = this.summary;
    }

    // Create CAPTION, if applicable
    if(this.caption) {
        this._elCaption = elTable.appendChild(document.createElement("caption"));
        this._elCaption.innerHTML = this.caption;
    }

    // Create THEAD
    this._initHead(elTable, this._oColumnSet);


    // Create TBODY for messages
    var elMsgBody = document.createElement("tbody");
    elMsgBody.tabIndex = -1;
    this._elMsgRow = elMsgBody.appendChild(document.createElement("tr"));
    var elMsgRow = this._elMsgRow;
    var elMsgCell = elMsgRow.appendChild(document.createElement("td"));
    elMsgCell.colSpan = this._oColumnSet.keys.length;
    this._elMsgCell = elMsgCell;
    this._elMsgBody = elTable.appendChild(elMsgBody);
    this.showLoadingMessage();

    // Create TBODY for data
    this._elBody = elTable.appendChild(document.createElement("tbody"));
    this._elBody.tabIndex = -1;
    YAHOO.util.Dom.addClass(this._elBody,YAHOO.widget.DataTable.CLASS_BODY);
    if(this.scrollable) {
        YAHOO.util.Dom.addClass(this._elBody,YAHOO.widget.DataTable.CLASS_SCROLLABLE);
    }
};

/**
 * Populates THEAD element with TH cells as defined by ColumnSet.
 *
 * @method _initHead
 * @private
 */
YAHOO.widget.DataTable.prototype._initHead = function() {
    var i,oColumn;
    
    // Create THEAD
    var elHead = document.createElement("thead");
    elHead.tabIndex = -1;

    // Iterate through each row of Column headers...
    var colTree = this._oColumnSet.tree;
    for(i=0; i<colTree.length; i++) {
        var elHeadRow = elHead.appendChild(document.createElement("tr"));
        elHeadRow.id = this.id+"-hdrow"+i;

        // ...and create THEAD cells
        for(var j=0; j<colTree[i].length; j++) {
            oColumn = colTree[i][j];
            var elHeadCell = elHeadRow.appendChild(document.createElement("th"));
            elHeadCell.id = oColumn.getId();
            this._initHeadCell(elHeadCell,oColumn,i,j);
        }
    }

    this._elHead = this._elTable.appendChild(elHead);
    
    // Add Resizer only after DOM has been updated...
    // ...and skip the last column
    for(i=0; i<this._oColumnSet.keys.length-1; i++) {
        oColumn = this._oColumnSet.keys[i];
        if(oColumn.resizeable && YAHOO.util.DD) {
            //TODO: deal with fixed width tables
            //TODO: no more oColumn.isLast
            if(!this.fixedWidth || (this.fixedwidth && !oColumn.isLast)) {
                // TODO: better way to get elHeadContainer
                var elHeadContainer = (YAHOO.util.Dom.getElementsByClassName(YAHOO.widget.DataTable.CLASS_HEADCONTAINER,"div",YAHOO.util.Dom.get(oColumn.getId())))[0];
                var elHeadResizer = elHeadContainer.appendChild(document.createElement("span"));
                elHeadResizer.id = oColumn.getId() + "-resizer";
                YAHOO.util.Dom.addClass(elHeadResizer,YAHOO.widget.DataTable.CLASS_HEADRESIZER);
                oColumn.ddResizer = new YAHOO.util.WidthResizer(
                        this, oColumn.getId(), elHeadResizer.id, elHeadResizer.id);
                var cancelClick = function(e) {
                    YAHOO.util.Event.stopPropagation(e);
                };
                YAHOO.util.Event.addListener(elHeadResizer,"click",cancelClick);
            }
            if(this.fixedWidth) {
                elHeadContainer.style.overflow = "hidden";
                elHeadContent.style.overflow = "hidden";
            }
        }
    }

    YAHOO.log("THEAD with " + this._oColumnSet.keys.length + " columns created","info",this.toString());
};

/**
 * Populates TH cell as defined by Column.
 *
 * @method _initHeadCell
 * @param elHeadCell {HTMLElement} TH cell element reference.
 * @param oColumn {YAHOO.widget.Column} Column object.
 * @param row {number} Row index.
 * @param col {number} Column index.
 * @private
 */
YAHOO.widget.DataTable.prototype._initHeadCell = function(elHeadCell,oColumn,row,col) {
    // Clear out the cell of prior content
    // TODO: purgeListeners and other validation-related things
    var index = this._nIndex;
    elHeadCell.columnIndex = col;
    if(oColumn.abbr) {
        elHeadCell.abbr = oColumn.abbr;
    }
    if(oColumn.width) {
        elHeadCell.style.width = oColumn.width;
    }
    if(oColumn.className) {
        YAHOO.util.Dom.addClass(elHeadCell,oColumn.className);
    }
    // Apply CSS for sorted tables
    if(this.sortedBy && this.sortedBy.colKey) {
        if(this.sortedBy.colKey == oColumn.key) {
            var sortClass = (this.sortedBy.dir && (this.sortedBy.dir != "asc")) ?
                    YAHOO.widget.DataTable.CLASS_SORTEDBYDESC :
                    YAHOO.widget.DataTable.CLASS_SORTEDBYASC;
            YAHOO.util.Dom.addClass(elHeadCell,sortClass);
            this.sortedBy._id = elHeadCell.id;
        }
    }

    elHeadCell.innerHTML = "";

    var elHeadContainer = elHeadCell.appendChild(document.createElement("div"));
    elHeadContainer.id = this.id+"-hdrow"+row+"-container"+col;
    YAHOO.util.Dom.addClass(elHeadContainer,YAHOO.widget.DataTable.CLASS_HEADCONTAINER);
    var elHeadContent = elHeadContainer.appendChild(document.createElement("span"));
    elHeadContent.id = this.id+"-hdrow"+row+"-text"+col;
    YAHOO.util.Dom.addClass(elHeadContent,YAHOO.widget.DataTable.CLASS_HEADTEXT);

    elHeadCell.rowSpan = oColumn.getRowSpan();
    elHeadCell.colSpan = oColumn.getColSpan();

    var contentText = oColumn.text || oColumn.key || "";
    if(oColumn.sortable) {
        YAHOO.util.Dom.addClass(elHeadContent,YAHOO.widget.DataTable.CLASS_SORTABLE);
        //TODO: Make hash configurable to be a server link
        //TODO: Make title configurable
        //TODO: Separate contentText from an accessibility link that says
        // Click to sort ascending and push it offscreen
        elHeadContent.innerHTML = "<a href=\"#\" title=\"Click to sort\">" + contentText + "</a>";
         //elHeadContent.innerHTML = contentText;

    }
    else {
        elHeadContent.innerHTML = contentText;
    }
};

/**
 * Add a new row to table body at position i if given, or to the bottom
 * otherwise. Does not fire any events.
 *
 * @method _addRow
 * @param oRecord {YAHOO.widget.Record} Record instance.
 * @param index {Number} Position at which to add row.
 * @return {String} ID of the added TR element.
 * @private
 */
YAHOO.widget.DataTable.prototype._addRow = function(oRecord, index) {
    this.hideTableMessages();

    // Is this an insert or an append?
    var insert = (isNaN(index)) ? false : true;
    if(!insert) {
        index = this._elBody.rows.length;
    }

    var oColumnSet = this._oColumnSet;
    var oRecordSet = this._oRecordSet;

    var elRow = (insert && this._elBody.rows[index]) ?
        this._elBody.insertBefore(document.createElement("tr"),this._elBody.rows[index]) :
        this._elBody.appendChild(document.createElement("tr"));
    var recId = oRecord.id;
    elRow.id = this.id+"-bdrow"+index;
    elRow.recordId = recId;

    // Create TBODY cells
    for(var j=0; j<oColumnSet.keys.length; j++) {
        var oColumn = oColumnSet.keys[j];
        var elCell = elRow.appendChild(document.createElement("td"));
        if (j == 0) {
            //This should be a reference to the first one in the row
            YAHOO.util.Dom.addClass(elCell, YAHOO.widget.DataTable.CLASS_FIRST_COLUMN);
        }
        elCell.id = this.id+"-bdrow"+index+"-cell"+j;
        elCell.headers = oColumn.id;
        elCell.columnIndex = j;
        elCell.headers = oColumnSet.headers[j];

        oColumn.format(elCell, oRecord);
        // need a div wrapper for safari?
        if(this.fixedWidth) {
            elCell.style.overflow = "hidden";
            //elCell.style.width = "20px";
        }
    }
    //This should be a reference to the last one in the row
    YAHOO.util.Dom.addClass(elCell, YAHOO.widget.DataTable.CLASS_LAST_COLUMN);

    if(this.isEmpty && (this._elBody.rows.length > 0)) {
        //TODO: hideMessages()
        //this._initRows()
        //this.isEmpty = false;
    }

    // Striping
    if(!insert) {
        if(index%2) {
            YAHOO.util.Dom.addClass(elRow, YAHOO.widget.DataTable.CLASS_ODD);
        }
        else {
            YAHOO.util.Dom.addClass(elRow, YAHOO.widget.DataTable.CLASS_EVEN);
        }
    }
    else {
        //TODO: pass in a subset for better performance
        this._restripeRows();
    }
    
    return elRow.id;
};

/**
 * Restripes rows by applying class YAHOO.widget.DataTable.CLASS_EVEN or
 * YAHOO.widget.DataTable.CLASS_ODD.
 *
 * @method _restripeRows
 * @param range {Number} (optional) Range defines a subset of rows to restripe.
 * @private
 */
YAHOO.widget.DataTable.prototype._restripeRows = function(range) {
    if(!range) {
        var rows = this._elBody.rows;
        for(var i=0; i<rows.length; i++) {
            if(i%2) {
                YAHOO.util.Dom.removeClass(rows[i], YAHOO.widget.DataTable.CLASS_EVEN);
                YAHOO.util.Dom.addClass(rows[i], YAHOO.widget.DataTable.CLASS_ODD);
            }
            else {
                YAHOO.util.Dom.removeClass(rows[i], YAHOO.widget.DataTable.CLASS_ODD);
                YAHOO.util.Dom.addClass(rows[i], YAHOO.widget.DataTable.CLASS_EVEN);
            }
        }
    }
    else {
        //TODO: allow restriping of a subset of rows for performance
    }
};

/**
 * Updates existing row at position i with data from the given Record. Does not
 * fire any events.
 *
 * @method _updateRow
 * @param oRecord {YAHOO.widget.Record} Record instance.
 * @param index {Number} Position at which to update row.
 * @return {String} ID of the updated TR element.
 * @private
 */
YAHOO.widget.DataTable.prototype._updateRow = function(oRecord, index) {
    this.hideTableMessages();

    var elRow = this._elBody.rows[index];
    elRow.recordId = oRecord.id;

    var columns = this._oColumnSet.keys;
    // ...Update TBODY cells with new data
    for(var j=0; j<columns.length; j++) {
        columns[j].format(elRow.cells[j], oRecord);
    }
    return elRow.id;
};

/**
 * Sets elements to selected state. Does not fire any events. Does not affect
 * internal tracker.
 *
 * @method _select
 * @param els {HTMLElement[] | String[]} Array of HTML elements by reference or ID string.
 * @private
 */
YAHOO.widget.DataTable.prototype._select = function(els) {
//TODO: put els in an array if it is just one element?
    for(var i=0; i<els.length; i++) {
        // Set the style
        YAHOO.util.Dom.addClass(YAHOO.util.Dom.get(els[i]),YAHOO.widget.DataTable.CLASS_SELECTED);
    }
    this._lastSelected = els[els.length-1];
};

/**
 * Sets elements to the unselected state. Does not fire any events. Does not
 * affect internal tracker.
 *
 * @method _unselect
 * @param els {HTMLElement[] | String[]} Array of HTML elements by reference or ID string.
 * @private
 */
YAHOO.widget.DataTable.prototype._unselect = function(els) {
    for(var i=0; i<els.length; i++) {
        // Remove the style
        YAHOO.util.Dom.removeClass(YAHOO.util.Dom.get(els[i]),YAHOO.widget.DataTable.CLASS_SELECTED);
    }
};

/**
 * Unselects all selected rows. Does not fire any events. Does not affect internal
 * tracker.
 *
 * @method _unselectAllRows
 * @private
 */
YAHOO.widget.DataTable.prototype._unselectAllRows = function() {
    var selectedRows = YAHOO.util.Dom.getElementsByClassName(YAHOO.widget.DataTable.CLASS_SELECTED,"tr",this._elBody);
    this._unselect(selectedRows);
};

/**
 * Unselects all selected cells.
 *
 * @method _unselectAllCells
 * @private
 */
YAHOO.widget.DataTable.prototype._unselectAllCells = function() {
    var selectedCells = YAHOO.util.Dom.getElementsByClassName(YAHOO.widget.DataTable.CLASS_SELECTED,"td",this._elBody);
    this._unselect(selectedCells);
};

/**
 * Deletes a given row element as well its corresponding Record in the RecordSet.
 * Does not fire any events.
 *
 * @method _deleteRow
 * @param elRow {element} HTML table row element reference.
 * @private
 */
YAHOO.widget.DataTable.prototype._deleteRow = function(elRow) {
//TODO: sniff elRow.rowIndex
    var allRows = this._elBody.rows;
    var id = elRow.id;
    var recordId = elRow.recordId;
    for(var i=0; i< allRows.length; i++) {
        if(id == allRows[i].id) {
            this._elBody.deleteRow(i);

            // Update the RecordSet
            this._oRecordSet.deleteRecord(i);
            break;
        }
    }
    if(this._elBody.rows.length === 0) {
        this.showEmptyMessage();
    }
};
/////////////////////////////////////////////////////////////////////////////
//
// Private DOM Event Handlers
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Handles blur events on the TABLE element.
 *
 * @method _onBlur
 * @param e {HTMLEvent} The blur event.
 * @param oSelf {YAHOO.widget.DataTable} DataTable instance.
 * @private
 */
YAHOO.widget.DataTable.prototype._onBlur = function(e, oSelf) {
    this._bFocused = false;
};

/**
 * Handles mouseover events on the TABLE element.
 *
 * @method _onMouseover
 * @param e {HTMLEvent} The mouseover event.
 * @param oSelf {YAHOO.widget.DataTable} DataTable instance.
 * @private
 */
YAHOO.widget.DataTable.prototype._onMouseover = function(e, oSelf) {
        var elTarget = YAHOO.util.Event.getTarget(e);
        var elTag = elTarget.tagName.toLowerCase();
        var knownTag = false;

        if (elTag != "table") {
            while(!knownTag) {
                switch(elTag) {
                    case "body":
                        knownTag = true;
                        break;
                    case "td":
                        oSelf.fireEvent("cellMouseoverEvent",{target:elTarget,event:e});
                        knownTag = true;
                        break;
                    case "th":
                        oSelf.fireEvent("headCellMouseoverEvent",{target:elTarget,event:e});
                        knownTag = true;
                        break;
                    default:
                        break;
                }
                elTarget = elTarget.parentNode;
                if(elTarget) {
                    elTag = elTarget.tagName.toLowerCase();
                }
                else {
                    break;
                }
            }
        }
        oSelf.fireEvent("tableMouseoverEvent",{target:elTarget,event:e});
};

/**
 * Handles mouseout events on the TABLE element.
 *
 * @method _onMouseout
 * @param e {HTMLEvent} The mouseout event.
 * @param oSelf {YAHOO.widget.DataTable} DataTable instance.
 * @private
 */
YAHOO.widget.DataTable.prototype._onMouseout = function(e, oSelf) {
        var elTarget = YAHOO.util.Event.getTarget(e);
        var elTag = elTarget.tagName.toLowerCase();
        var knownTag = false;

        if (elTag != "table") {
            while(!knownTag) {
                switch(elTag) {
                    case "body":
                        knownTag = true;
                        break;
                    case "td":
                        oSelf.fireEvent("cellMouseoutEvent",{target:elTarget,event:e});
                        knownTag = true;
                        break;
                    case "th":
                        oSelf.fireEvent("headCellMouseoutEvent",{target:elTarget,event:e});
                        knownTag = true;
                        break;
                    default:
                        break;
                }
                elTarget = elTarget.parentNode;
                if(elTarget) {
                    elTag = elTarget.tagName.toLowerCase();
                }
                else {
                    break;
                }
            }
        }
        oSelf.fireEvent("tableMouseoutEvent",{target:elTarget,event:e});
};

/**
 * Handles mousedown events on the TABLE element.
 *
 * @method _onMousedown
 * @param e {HTMLEvent} The mousedown event.
 * @param oSelf {YAHOO.widget.DataTable} DataTable instance.
 * @private
 */
YAHOO.widget.DataTable.prototype._onMousedown = function(e, oSelf) {
        //YAHOO.util.Event.stopEvent(e);
        var elTarget = YAHOO.util.Event.getTarget(e);
        var elTag = elTarget.tagName.toLowerCase();
        var knownTag = false;

        if (elTag != "table") {
            while(!knownTag) {
                switch(elTag) {
                    case "body":
                        knownTag = true;
                        break;
                    case "td":
                        YAHOO.util.Event.stopEvent(e);
                        oSelf.fireEvent("cellMousedownEvent",{target:elTarget,event:e});
                        knownTag = true;
                        break;
                    case "th":
                        YAHOO.util.Event.stopEvent(e);
                        oSelf.fireEvent("headCellMousedownEvent",{target:elTarget,event:e});
                        knownTag = true;
                        break;
                    default:
                        break;
                }
                elTarget = elTarget.parentNode;
                if(elTarget) {
                    elTag = elTarget.tagName.toLowerCase();
                }
                else {
                    break;
                }
            }
        }
        oSelf.fireEvent("tableMousedownEvent",{target:elTarget,event:e});
};

/**
 * Handles click events on the TABLE element.
 *
 * @method _onClick
 * @param e {HTMLEvent} The click event.
 * @param oSelf {YAHOO.widget.DataTable} DataTable instance.
 * @private
 */
YAHOO.widget.DataTable.prototype._onClick = function(e, oSelf) {
    var elTarget = YAHOO.util.Event.getTarget(e);
    var elTag = elTarget.tagName.toLowerCase();
    var knownTag = false; // True if event should stop propagating

    if(oSelf.activeEditor) { //&& (oSelf.activeEditor.column != column)
        oSelf.activeEditor.hide();
        oSelf.activeEditor = null;

        // Editor causes widget to lose focus
        oSelf._bFocused = false;
        oSelf.focusTable();
    }

    if (elTag != "table") {
        while(!knownTag) {
            switch(elTag) {
                case "body":
                    knownTag = true;
                    break;
                case "input":
                    if(elTarget.type.toLowerCase() == "checkbox") {
                        oSelf.fireEvent("checkboxClickEvent",{target:elTarget,event:e});
                    }
                    else if(elTarget.type.toLowerCase() == "radio") {
                        oSelf.fireEvent("radioClickEvent",{target:elTarget,event:e});
                    }
                    knownTag = true;
                    break;
                case "td":
                    YAHOO.util.Event.stopEvent(e);
                    oSelf.fireEvent("cellClickEvent",{target:elTarget,event:e});
                    knownTag = true;
                    break;
                case "th":
                    YAHOO.util.Event.stopEvent(e);
                    oSelf.fireEvent("headCellClickEvent",{target:elTarget,event:e});
                    knownTag = true;
                    break;
                default:
                    break;
            }
            elTarget = elTarget.parentNode;
            elTag = elTarget.tagName.toLowerCase();
        }
    }
    oSelf.focusTable();
    oSelf.fireEvent("tableClickEvent",{target:elTarget,event:e});
};

/**
 * Handles doubleclick events on the TABLE element.
 *
 * @method _onDoubleclick
 * @param e {HTMLEvent} The doubleclick event.
 * @param oSelf {YAHOO.widget.DataTable} DataTable instance.
 * @private
 */
YAHOO.widget.DataTable.prototype._onDoubleclick = function(e, oSelf) {
    var elTarget = YAHOO.util.Event.getTarget(e);
    var elTag = elTarget.tagName.toLowerCase();
    var knownTag = false;

    if(oSelf.activeEditor) { //&& (oSelf.activeEditor.column != column)
        oSelf.activeEditor.hide();
        oSelf.activeEditor = null;
        
        // Editor causes widget to lose focus
        oSelf._bFocused = false;
        oSelf.focusTable();
    }

    if (elTag != "table") {
        while(!knownTag) {
            switch(elTag) {
                case "body":
                    knownTag = true;
                    break;
                case "td":
                    YAHOO.util.Event.stopEvent(e);
                    oSelf.fireEvent("cellDoubleclickEvent",{target:elTarget,event:e});
                    knownTag = true;
                    break;
                case "th":
                    YAHOO.util.Event.stopEvent(e);
                    oSelf.fireEvent("headCellDoubleclickEvent",{target:elTarget,event:e});
                    knownTag = true;
                    break;
                default:
                    break;
            }
            elTarget = elTarget.parentNode;
            elTag = elTarget.tagName.toLowerCase();
        }
    }
    oSelf.fireEvent("tableDoubleclickEvent",{target:elTarget,event:e});
};

/**
 * Handles keypress events on the TABLE. Mainly to support stopEvent on Mac.
 *
 * @method _onKeypress
 * @param e {HTMLEvent} The key event.
 * @param oSelf {YAHOO.widget.DataTable} DataTable instance.
 * @private
 */
YAHOO.widget.DataTable.prototype._onKeypress = function(e, oSelf) {
    var isMac = (navigator.userAgent.toLowerCase().indexOf("mac") != -1);
    if(isMac) {
        // arrow down
        if(e.keyCode == 40) {
            YAHOO.util.Event.stopEvent(e);
        }
        // arrow up
        else if(e.keyCode == 38) {
            YAHOO.util.Event.stopEvent(e);
        }
    }
};

/**
 * Handles keydown events on the TABLE. Executes arrow selection.
 *
 * @method _onKeydown
 * @param e {HTMLEvent} The key event.
 * @param oSelf {YAHOO.widget.DataTable} DataTable instance.
 * @private
 */
YAHOO.widget.DataTable.prototype._onKeydown = function(e, oSelf) {
    var oldSelected = oSelf._lastSelected;
    // Only move selection if one is already selected
    // TODO: config to allow selection even if one is NOT already selected
    // TODO: if something isn't selected already, arrow key should select first or last one
    if(oldSelected && oSelf.isSelected(oldSelected)) {
        var newSelected;
        // arrow down
        if(e.keyCode == 40) {
            YAHOO.util.Event.stopEvent(e);
            // row mode
            if(oldSelected.tagName.toLowerCase() == "tr") {
                // We have room to move down
                if(oldSelected.sectionRowIndex+1 < oSelf._elBody.rows.length) {
                            if(!e.shiftKey) {
                                oSelf.unselectAllRows();
                            }
                            newSelected = oSelf._elBody.rows[oldSelected.sectionRowIndex+1];
                            oSelf.select(newSelected);
                            
                }
            }
            // cell mode
            else if(oldSelected.tagName.toLowerCase() == "td") {
                /*// We have room to move down
                if(oldSelected.sectionRowIndex+1 < oSelf._elBody.rows.length) {
                            if(!e.shiftKey) {
                                oSelf.unselectAllRows();
                            }
                            newSelected = oSelf._elBody.rows[oldSelected.sectionRowIndex+1];
                            oSelf.select(newSelected);
                }*/
            }
            // Arrows can cause widget to lose focus
            oSelf._bFocused = false;
            oSelf.focusTable();
        }
        // arrow up
        else if(e.keyCode == 38) {
            YAHOO.util.Event.stopEvent(e);
            // row mode
            if(oldSelected.tagName.toLowerCase() == "tr") {
                // We have room to move up
                if((oldSelected.sectionRowIndex > 0)) {
                            if(!e.shiftKey) {
                                oSelf.unselectAllRows();
                            }
                            newSelected = oSelf._elBody.rows[oldSelected.sectionRowIndex-1];
                            oSelf.select(newSelected);
                }
            }
            // cell mode
            else if(oldSelected.tagName.toLowerCase() == "td") {
                // We have room to move up
                if((oldSelected.sectionRowIndex > 0)) {
                            if(!e.shiftKey) {
                                oSelf.unselectAllRows();
                            }
                            newSelected = oSelf._elBody.rows[oldSelected.sectionRowIndex-1];
                            oSelf.select(newSelected);
                }
            }
            // Arrows can cause widget to lose focus
            oSelf._bFocused = false;
            oSelf.focusTable();
        }
    }
};

/**
 * Handles keyup events on the TABLE. Executes deletion
 *
 * @method _onKeyup
 * @param e {HTMLEvent} The key event.
 * @param oSelf {YAHOO.widget.DataTable} DataTable instance.
 * @private
 */
YAHOO.widget.DataTable.prototype._onKeyup = function(e, oSelf) {
    var key = YAHOO.util.Event.getCharCode(e);
    // delete
    if(key == 46) {//TODO: && this.isFocused
        //TODO: delete row
    }
};

/**
 * Handles keyup events on the DOCUMENT. Executes interaction with editor.
 *
 * @method _onDocumentKeyup
 * @param e {HTMLEvent} The key event.
 * @param oSelf {YAHOO.widget.DataTable} DataTable instance.
 * @private
 */
YAHOO.widget.DataTable.prototype._onDocumentKeyup = function(e, oSelf) {
    // esc Clears active editor
    if((e.keyCode == 27) && (oSelf.activeEditor)) {
        oSelf.activeEditor.hide();
        oSelf.activeEditor = null;
        
        // Editor causes widget to lose focus
        oSelf._bFocused = false;
        oSelf.focusTable();
    }
    // enter Saves active editor data
    if((e.keyCode == 13) && (oSelf.activeEditor)) {
        var elCell = oSelf.activeEditor.cell;
        var oColumn = oSelf.activeEditor.column;
        var oRecord = oSelf.activeEditor.record;
        var oldValue = oRecord[oColumn.key];
        var newValue = oSelf.activeEditor.getValue();
        
        //Update Record
        //TODO: Column.key may be null!
        oSelf._oRecordSet.updateRecord(oRecord,oColumn.key,newValue);

        //Update cell
        oSelf.formatCell(elCell);

        // Hide editor
        oSelf.activeEditor.hide();
        oSelf.activeEditor = null;

        // Editor causes widget to lose focus
        oSelf._bFocused = false;
        oSelf.focusTable();
        oSelf.fireEvent("cellEditEvent",{target:elCell,oldData:oldValue,newData:newValue});
    }
};

/**
 * Handles click events on paginator links.
 *
 * @method _onPagerClick
 * @param e {HTMLEvent} The click event.
 * @param oSelf {YAHOO.widget.DataTable} DataTable instance.
 * @private
 */
YAHOO.widget.DataTable.prototype._onPagerClick = function(e, oSelf) {
    var elTarget = YAHOO.util.Event.getTarget(e);
    var elTag = elTarget.tagName.toLowerCase();
    var knownTag = false; // True if event should stop propagating

    if (elTag != "table") {
        while(!knownTag) {
            switch(elTag) {
                case "body":
                    knownTag = true;
                    break;
                case "a":
                    YAHOO.util.Event.stopEvent(e);
                    switch(elTarget.className) {
                        case YAHOO.widget.DataTable.CLASS_PAGELINK:
                            oSelf.showPage(parseInt(elTarget.innerHTML,10));
                            break;
                        case YAHOO.widget.DataTable.CLASS_FIRSTLINK:
                            oSelf.showPage(1);
                            break;
                        case YAHOO.widget.DataTable.CLASS_LASTLINK:
                            oSelf.showPage(oSelf._totalPages);
                            break;
                        case YAHOO.widget.DataTable.CLASS_PREVLINK:
                            oSelf.showPage(oSelf.pageCurrent-1);
                            break;
                        case YAHOO.widget.DataTable.CLASS_NEXTLINK:
                            oSelf.showPage(oSelf.pageCurrent+1);
                            break;
                    }
                    knownTag = true;
                    break;
                default:
                    break;
            }
            elTarget = elTarget.parentNode;
            if(elTarget) {
                elTag = elTarget.tagName.toLowerCase();
            }
            else {
                break;
            }
        }
    }
};

/**
 * Handles change events on paginator SELECT.
 *
 * @method _onPagerSelect
 * @param e {HTMLEvent} The change event.
 * @param oSelf {YAHOO.widget.DataTable} DataTable instance.
 * @private
 */
YAHOO.widget.DataTable.prototype._onPagerSelect = function(e, oSelf) {
    var elTarget = YAHOO.util.Event.getTarget(e);
    var elTag = elTarget.tagName.toLowerCase();

    // How many rows per page
    var oldRowsPerPage = oSelf.rowsPerPage;
    var rowsPerPage = parseInt(elTarget[elTarget.selectedIndex].text,10);
    if(rowsPerPage && (rowsPerPage != oSelf.rowsPerPage)) {
        if(rowsPerPage > oldRowsPerPage) {
            oSelf.pageCurrent = 1;
        }
        oSelf.rowsPerPage = rowsPerPage;
        oSelf.paginateRows();
    }
};

/////////////////////////////////////////////////////////////////////////////
//
// Private Custom Event Handlers
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Handles row delete events.
 *
 * @method _onRowDelete
 * @param oArgs.rowIndexes {Number[]} The indexes of the deleted rows.
 * @private
 */
YAHOO.widget.DataTable.prototype._onRowDelete = function(oArgs) {
    this._restripeRows();
};

/**
 * Passes along recordSetUpdate Event when recordUpdateEvent is caught from RecordSet.
 *
 * @event _onRecordUpdate
 * @param oArgs.record {YAHOO.widget.Record} The Record instance.
 * @param oArgs.key {String} The Record key.
 * @param oArgs.newData {Object} New data.
 * @param oArgs.oldData {Object} New data.
 * @private
 */
YAHOO.widget.DataTable.prototype._onRecordUpdate = function(oArgs) {
    this.fireEvent("recordSetUpdateEvent",oArgs);
};

/////////////////////////////////////////////////////////////////////////////
//
// Public member variables
//
/////////////////////////////////////////////////////////////////////////////

/**
 * DataSource instance.
 *
 * @property dataSource
 * @type YAHOO.util.DataSource
 */
YAHOO.widget.DataTable.prototype.dataSource = null;

/**
 * Initial request to send to DataSource.
 *
 * @property initialRequest
 * @type String
 * @default ""
 */
YAHOO.widget.DataTable.prototype.initialRequest = "";

/**
 * Defines value of CAPTION attribute.
 *
 * @property caption
 * @type String
 */
YAHOO.widget.DataTable.prototype.caption = null;

/**
 * Defines value of SUMMARY attribute.
 *
 * @property summary
 * @type String
 */
YAHOO.widget.DataTable.prototype.summary = null;

/**
 * True if DataTable's width is a fixed size.
 *
 * @property fixedWidth
 * @type Boolean
 * @default false
 */
YAHOO.widget.DataTable.prototype.fixedWidth = false;

/**
 * True if TBODY should scroll while THEAD remains fixed.
 *
 * @property scrollable
 * @type Boolean
 * @default false
 */
YAHOO.widget.DataTable.prototype.scrollable = false;

/**
 * True if only one row may be selected at a time.
 *
 * @property rowSingleSelect
 * @type Boolean
 * @default false
 */
YAHOO.widget.DataTable.prototype.rowSingleSelect = false;

/**
 * ContextMenu instance.
 *
 * @property contextMenu
 * @type YAHOO.widget.ContextMenu
 */
YAHOO.widget.DataTable.prototype.contextMenu = null;

/**
 * Current page number.
 *
 * @property pageCurrent
 * @type Number
 * @default 1
 */
YAHOO.widget.DataTable.prototype.pageCurrent = 1;

/**
 * Rows per page.
 *
 * @property rowsPerPage
 * @type Number
 * @default 500
 */
YAHOO.widget.DataTable.prototype.rowsPerPage = 500;

/**
 * Record index of first row of current page.
 *
 * @property startRecordIndex
 * @type Number
 * @default 1
 */
YAHOO.widget.DataTable.prototype.startRecordIndex = 1;

/**
 * Maximum number of pagination page links to show. Any page links beyond this number are
 * available through the "&lt;" and "&gt;" links. A negative value will display all page links.
 *
 * @property pageLinksLength
 * @type Number
 * @default -1
 */
YAHOO.widget.DataTable.prototype.pageLinksLength = -1;

/**
 * Options to show in the rows-per-page pagination dropdown, should be an array
 * of numbers. Null or an empty array causes no dropdown to be displayed.
 *
 * @property rowsPerPageDropdown
 * @type Number[]
 */
YAHOO.widget.DataTable.prototype.rowsPerPageDropdown = null;
        
/**
 * First pagination page link.
 *
 * @property pageLinksStart
 * @type Number
 * @default 1
 */
YAHOO.widget.DataTable.prototype.pageLinksStart = 1;

/**
 * An array of DIV elements into which pagination elements can go.
 *
 * @property pagers
 * @type HTMLElement[]
 */
YAHOO.widget.DataTable.prototype.pagers = null;

/**
 * True if the DataTable is empty of data. False if DataTable is populated with
 * data from RecordSet.
 *
 * @property isEmpty
 * @type Boolean
 */
YAHOO.widget.DataTable.prototype.isEmpty = false;

/**
 * Object literal holds sort metadata:
 *  sortedBy.colKey
 *  sortedBy.dir
 *
 *
 * @property sortedBy
 * @type Object
 */
YAHOO.widget.DataTable.prototype.sortedBy = null;


/////////////////////////////////////////////////////////////////////////////
//
// Public methods
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Public accessor to the unique name of the DataSource instance.
 *
 * @method toString
 * @return {String} Unique name of the DataSource instance.
 */

YAHOO.widget.DataTable.prototype.toString = function() {
    return "DataTable " + this._sName;
};

/**
 * Returns element reference to TABLE.
 *
 * @method getTable
 * @return {HTMLElement} Reference to TABLE element.
 */
YAHOO.widget.DataTable.prototype.getTable = function() {
    return(this._elTable);
};

/**
 * Returns element reference to THEAD.
 *
 * @method getHead
 * @return {HTMLElement} Reference to THEAD element.
 */
YAHOO.widget.DataTable.prototype.getHead = function() {
    return(this._elHead);
};

/**
 * Returns element reference to TBODY.
 *
 * @method getBody
 * @return {HTMLElement} Reference to TBODY element.
 */
YAHOO.widget.DataTable.prototype.getBody = function() {
    return(this._elBody);
};

/**
 * Returns element reference to given TR cell.
 *
 * @method getRow
 * @param index {Number} Row number.
 * @return {HTMLElement} Reference to TR element.
 */
YAHOO.widget.DataTable.prototype.getRow = function(index) {
    return(this._elBody.rows[index]);
};

/**
 * Returns element reference to given TD cell.
 *
 * @method getCell
 * @param row {Number} Row number.
 * @param col {Number} Column number.
 * @return {HTMLElement} Reference to TD element.
 */
YAHOO.widget.DataTable.prototype.getCell = function(row, col) {
    return(this._elBody.rows[row].cells[col]);
};

/**
 * Placeholder row to indicate table data is empty.
 *
 * @method showEmptyMessage
 */
YAHOO.widget.DataTable.prototype.showEmptyMessage = function() {
    if(this.isEmpty) {
        return;
    }
    if(this.isLoading) {
        this.hideTableMessages();
    }

    this._elMsgBody.style.display = "";
    var elCell = this._elMsgCell;
    elCell.className = YAHOO.widget.DataTable.CLASS_EMPTY;
    elCell.innerHTML = YAHOO.widget.DataTable.MSG_EMPTY;
    this.isEmpty = true;
};

/**
 * Placeholder row to indicate table data is loading.
 *
 * @method showLoadingMessage
 */
YAHOO.widget.DataTable.prototype.showLoadingMessage = function() {
    if(this.isLoading) {
        return;
    }
    if(this.isEmpty) {
        this.hideTableMessages();
    }

    this._elMsgBody.style.display = "";
    var elCell = this._elMsgCell;
    elCell.className = YAHOO.widget.DataTable.CLASS_LOADING;
    elCell.innerHTML = YAHOO.widget.DataTable.MSG_LOADING;
    this.isLoading = true;
};

/**
 * Hide any placeholder message row.
 *
 * @method hideTableMessages
 */
YAHOO.widget.DataTable.prototype.hideTableMessages = function() {
    if(!this.isEmpty && !this.isLoading) {
        return;
    }

    this._elMsgBody.style.display = "none";

    this.isEmpty = false;
    this.isLoading = false;
};

/**
 * Sets focus on the TABLE element.
 *
 * @method focusTable
 */
YAHOO.widget.DataTable.prototype.focusTable = function() {
    var elTable = this._elTable;
    if(!this._bFocused) {
        // http://developer.mozilla.org/en/docs/index.php?title=Key-navigable_custom_DHTML_widgets
        // The timeout is necessary in both IE and Firefox 1.5, to prevent scripts from doing
        // strange unexpected things as the user clicks on buttons and other controls.
        setTimeout(function() { elTable.focus(); },0);
        this._bFocused = true;
        this.fireEvent("tableFocusEvent");
    }
};

/**
 * Overridable method gives implementers a hook to access data before
 * it gets added to RecordSet and rendered to the TBODY.
 *
 * @method doBeforeLoadData
 * @param sRequest {String} Original request.
 * @param oResponse {Object} Response object.
 * @return {Boolean} Return true to continue loading data into RecordSet and
 * updating DataTable with new Records, false to cancel.
 */
YAHOO.widget.DataTable.prototype.doBeforeLoadData = function(sRequest, oResponse) {
    return true;
};

/**
 * Add rows to bottom of table body.
 *
 * @method appendRow
 * @param aRecords {YAHOO.widget.Record[]} Array of Records.
 */
YAHOO.widget.DataTable.prototype.appendRows = function(aRecords) {
    if(aRecords && aRecords.length > 0) {
        this.hideTableMessages();

        var rowIds = [];
        for(var i=0; i<aRecords.length; i++) {
            var rowId = this._addRow(aRecords[i]);
            rowIds.push(rowId);
        }
        
        this.fireEvent("rowAppendEvent", {rowIds:rowIds});
    }
};

/**
 * Add rows to top of table body.
 *
 * @method insertRows
 * @param aRecords {YAHOO.widget.Record[]} Array of Records.
 */
YAHOO.widget.DataTable.prototype.insertRows = function(aRecords) {
    if(aRecords && aRecords.length > 0) {
        this.hideTableMessages();

        var rowIds = [];
        for(var i=0; i<aRecords.length; i++) {
            var rowId = this._addRow(aRecords[i],0);
            rowIds.push(rowId);
        }
        
        this.fireEvent("rowInsertEvent", {rowIds:rowIds});
    }
};

/**
 * Replaces existing rows of table body with new Records.
 *
 * @method replaceRows
 * @param aRecords {YAHOO.widget.Record[]} Array of Records.
 */
YAHOO.widget.DataTable.prototype.replaceRows = function(aRecords) {
    var i;
    
    if(aRecords && aRecords.length > 0) {
        this.hideTableMessages();

        var elBody = this._elBody;
        var elRows = this._elBody.rows;
        
        // Remove extra rows
        while(elBody.hasChildNodes() && (elRows.length > aRecords.length)) {
            elBody.deleteRow(0);
        }
        
        // Unselect rows in the UI but keep tracking selected rows
        var selectedRecords = this.getSelectedRecordIds();
        if(selectedRecords.length > 0) {
            this._unselectAllRows();
        }
        
        var rowIds = [];
        // Format in-place existing rows
        for(i=0; i<elRows.length; i++) {
            if(aRecords[i]) {
                var oRecord = aRecords[i];
                rowIds.push(this._updateRow(oRecord,i));
            }
        }

        // Add rows as necessary
        for(i=elRows.length; i<aRecords.length; i++) {
            rowIds.push(this._addRow(aRecords[i]));
        }
        
        // Select any rows as necessary
        for(i=0; i<selectedRecords.length; i++) {
            var allRows = elBody.rows;
            for(var j=0; j<allRows.length; j++) {
                if(selectedRecords[i] == allRows[j].recordId) {
                    this._select([allRows[j]]);
                }
            }
        }
        
        this.fireEvent("rowReplaceEvent", {rowIds:rowIds});
    }
};

/**
 * Convenience method to add a new row to table body at position index if given,
 * or to the bottom otherwise.
 *
 * @method addRow
 * @param oRecord {YAHOO.widget.Record} Record instance.
 * @param index {Number} Position at which to add row.
 */
YAHOO.widget.DataTable.prototype.addRow = function(oRecord, index) {
    if(oRecord) {
        var rowId = this._addRow(oRecord, index);
        if(index !== undefined) {
            this.fireEvent("rowInsertEvent", {rowIds:[rowId]});
        }
        else {
            this.fireEvent("rowAppendEvent", {rowIds:[rowId]});
        }
    }
};

/**
 * Updates existing row at position index with data from the given Record.
 *
 * @method updateRow
 * @param oRecord {YAHOO.widget.Record} Record instance.
 * @param index {Number} Position at which to update row.
 */
YAHOO.widget.DataTable.prototype.updateRow = function(oRecord, index) {
    if(oRecord) {
        var rowId = this._updateRow(oRecord, index);
        this.fireEvent("rowUpdateEvent", {rowIds:[rowId]});
    }
};

/**
 * Calls delete on selected rows.
 *
 * @method deleteSelectedRows
 */
YAHOO.widget.DataTable.prototype.deleteRows = function(rows) {
    var rowIndexes = [];
    for(var i=0; i<rows.length; i++) {
        var rowIndex = (rows[i].sectionRowIndex !== undefined) ? rows[i].sectionRowIndex : null;
        rowIndexes.push(rowIndex);
        this._deleteRow(rows[i]);
        this.fireEvent("rowDeleteEvent", {rowIndexes:rowIndexes});
    }
};

/**
 * Deletes a given row element as well its corresponding Record in the RecordSet.
 *
 * @method deleteRow
 * @param elRow {element} HTML table row element reference.
 */
YAHOO.widget.DataTable.prototype.deleteRow = function(elRow) {
    if(elRow) {
        var rowIndex = (elRow.sectionRowIndex !== undefined) ? elRow.sectionRowIndex : null;
        this._deleteRow(elRow);
        this.fireEvent("rowDeleteEvent", {rowIndexes:[rowIndex]});
    }
};

/**
 * Sets one or more elements to the highlighted state.
 *
 * @method highlight
 * @param els {HTMLElement | String | HTMLElement[] | String[]} HTML TR element
 * reference, TR String ID, array of HTML TR element, or array of TR element IDs.
 */
YAHOO.widget.DataTable.prototype.highlight = function(els) {
    if(els.constructor != Array) {
        els = [els];
    }
    YAHOO.util.Dom.addClass(els,YAHOO.widget.DataTable.CLASS_HIGHLIGHT);
    this.fireEvent("highlightEvent",{els:els});
};

/**
 * Sets one or more elements to the unhighlighted state.
 *
 * @method unhighlight
 * @param els {HTMLElement | String | HTMLElement[] | String[]} HTML TR element
 * reference, TR String ID, array of HTML TR element, or array of TR element IDs.
 */
YAHOO.widget.DataTable.prototype.unhighlight = function(els) {
    if(els.constructor != Array) {
        els = [els];
    }
    YAHOO.util.Dom.removeClass(els,YAHOO.widget.DataTable.CLASS_HIGHLIGHT);
    this.fireEvent("unhighlightEvent",{els:els});
};


/**
 * Sets one or more elements to the selected state.
 *
 * @method select
 * @param els {HTMLElement | String | HTMLElement[] | String[]} HTML TR element
 * reference, TR String ID, array of HTML TR element, or array of TR element IDs.
 */
YAHOO.widget.DataTable.prototype.select = function(els) {
    if(els) {
        if(els.constructor != Array) {
            els = [els];
        }
        this._select(els);
        
        // Add Record ID to internal tracker
        var tracker = this._aSelectedRecords || [];
        for(var i=0; i<els.length; i++) {
            var id = els[i].recordId;
            // Remove if already there
            // Use Array.indexOf if available...
            if(tracker.indexOf && (tracker.indexOf(id) >  -1)) {
                tracker.splice(tracker.indexOf(id),1);
            }
            // ...or do it the old-fashioned way
            else {
                for(var j=0; j<tracker.length; j++) {
                   if(tracker[j] === id){
                        tracker.splice(j,1);
                    }
                }
            }
            // Add to the end
            tracker.push(id);
        }
        this._aSelectedRecords = tracker;
        this.fireEvent("selectEvent",{els:els});
    }
};

/**
 * Sets one or more elements to the unselected state.
 *
 * @method unselect
 * @param els {HTMLElement | String | HTMLElement[] | String[]} HTML element
 * reference, element ID, array of HTML elements, or array of element IDs
 */
YAHOO.widget.DataTable.prototype.unselect = function(els) {
    if(els) {
        if(els.constructor != Array) {
            els = [els];
        }
        this._unselect(els);
        // Remove Record ID from internal tracker
        var tracker = this._aSelectedRecords || [];
        for(var i=0; i<els.length; i++) {
            var id = els[i].recordId;
        
            // Use Array.indexOf if available...
            if(tracker.indexOf && (tracker.indexOf(id) >  -1)) {
                tracker.splice(tracker.indexOf(id),1);
            }
            // ...or do it the old-fashioned way
            else {
                for(var j=0; j<tracker.length; j++) {
                    if(tracker[j] === id){
                        tracker.splice(j,1);
                    }
                }
            }
        }
        this._aSelectedRecords = tracker;
        this.fireEvent("unselectEvent",{els:els});
    }
};

/**
 * Unselects all selected rows.
 *
 * @method unselectAllRows
 */
YAHOO.widget.DataTable.prototype.unselectAllRows = function() {
    var selectedRows = YAHOO.util.Dom.getElementsByClassName(YAHOO.widget.DataTable.CLASS_SELECTED,"tr",this._elBody);
    this.unselect(selectedRows);
    this.fireEvent("unselectEvent", {els:selectedRows});
};

/**
 * Unselects all selected cells.
 *
 * @method unselectAllCells
 */
YAHOO.widget.DataTable.prototype.unselectAllCells = function() {
    var selectedCells = YAHOO.util.Dom.getElementsByClassName(YAHOO.widget.DataTable.CLASS_SELECTED,"td",this._elBody);
    this.unselect(selectedCells);
    this.fireEvent("unselectEvent", {els:selectedCells});
};


/**
 * Returns true if given element is select, false otherwise.
 *
 * @method isSelected
 * @param el {element} HTML element reference.
 * @return {boolean} True if element is selected.
 */
YAHOO.widget.DataTable.prototype.isSelected = function(el) {
    return YAHOO.util.Dom.hasClass(el,YAHOO.widget.DataTable.CLASS_SELECTED);
};

/**
 * Returns array of selected Record IDs.
 *
 * @method getSelectedRecordIds
 * @return {HTMLElement[]} Array of selected TR elements.
 */
YAHOO.widget.DataTable.prototype.getSelectedRecordIds = function() {
    return this._aSelectedRecords || [];
};

/**
 * Returns array of selected rows.
 *
 * @method getSelectedRows
 * @return {HTMLElement[]} Array of selected TR elements.
 */
YAHOO.widget.DataTable.prototype.getSelectedRows = function() {
    //TODO: keep internal array if this is non performant
    return YAHOO.util.Dom.getElementsByClassName(YAHOO.widget.DataTable.CLASS_SELECTED,"tr",this._elBody);
};

/**
 * Returns array of selected TD cells.
 *
 * @method getSelectedCells
 * @return {HTMLElement[]} Array of selected TD elements.
 */
YAHOO.widget.DataTable.prototype.getSelectedCells = function() {
    //TODO: keep internal array
    return YAHOO.util.Dom.getElementsByClassName(YAHOO.widget.DataTable.CLASS_SELECTED,"td",this._elBody);
};

/**
 * Returns pointer to the DataTable instance's ColumnSet instance.
 *
 * @method getColumnSet
 * @return {YAHOO.widget.ColumnSet} ColumnSet instance.
 */
YAHOO.widget.DataTable.prototype.getColumnSet = function() {
    return this._oColumnSet;
};

/**
 * Returns pointer to the DataTable instance's RecordSet instance.
 *
 * @method getRecordSet
 * @return {YAHOO.widget.RecordSet} RecordSet instance.
 */
YAHOO.widget.DataTable.prototype.getRecordSet = function() {
    return this._oRecordSet;
};

/**
 * Displays a specific page of a paginated DataTable.
 *
 * @method showPage
 * @param nPage {Number} Which page.
 */
YAHOO.widget.DataTable.prototype.showPage = function(nPage) {
    // Validate input
    if(!nPage || isNaN(nPage) || (nPage < 1) || (nPage > this._totalPages)) {
        nPage = 1;
    }
    this.pageCurrent = nPage;
    this.paginateRows();
};

/**
 * If pagination is enabled, paginates all data in RecordSet and renders
 * paginator UI, others renders normal TBODY without any paginator UI.
 *
 * @method paginateRows
 */
YAHOO.widget.DataTable.prototype.paginateRows = function() {
    var i;
    
    // How many total Records
    var recordsLength = this._oRecordSet.getLength();
    
    // How many rows this page
    var maxRows = (this.rowsPerPage < recordsLength) ?
            this.rowsPerPage : recordsLength;

    // How many total pages
    this._totalPages = Math.ceil(recordsLength / maxRows);

    // First row of this page
    this.startRecordIndex = (this.pageCurrent-1) * this.rowsPerPage;

    // How many page links to display
    var pageLinksLength =
            ((this.pageLinksLength > 0) && (this.pageLinksLength < this._totalPages)) ?
            this.pageLinksLength : this._totalPages;

    // First link of this page
    this.pageLinksStart = (Math.ceil(this.pageCurrent/pageLinksLength-1) * pageLinksLength) + 1;

    // Show Records for this page
    var pageRecords = this._oRecordSet.getRecords(this.startRecordIndex, this.rowsPerPage);
    this.replaceRows(pageRecords);

    if(this.rowsPerPage < recordsLength) {
        // Markup for page links
        var isFirstPage = (this.pageCurrent == 1) ? true : false;
        var isLastPage = (this.pageCurrent == this._totalPages) ? true : false;
        var firstPageLink = (isFirstPage) ?
                " <span class=\"" + YAHOO.widget.DataTable.CLASS_FIRSTPAGE + "\">&lt;&lt;</span> " :
                " <a href=\"#\" class=\"" + YAHOO.widget.DataTable.CLASS_FIRSTLINK + "\">&lt;&lt;</a> ";
        var prevPageLink = (isFirstPage) ?
                " <span class=\"" + YAHOO.widget.DataTable.CLASS_PREVPAGE + "\">&lt;</span> " :
                " <a href=\"#\" class=\"" + YAHOO.widget.DataTable.CLASS_PREVLINK + "\">&lt;</a> " ;
        var nextPageLink = (isLastPage) ?
                " <span class=\"" + YAHOO.widget.DataTable.CLASS_NEXTPAGE + "\">&gt;</span> " :
                " <a href=\"#\" class=\"" + YAHOO.widget.DataTable.CLASS_NEXTLINK + "\">&gt;</a> " ;
        var lastPageLink = (isLastPage) ?
                " <span class=\"" + YAHOO.widget.DataTable.CLASS_LASTPAGE + "\">&gt;&gt;</span> " :
                " <a href=\"#\" class=\"" + YAHOO.widget.DataTable.CLASS_LASTLINK + "\">&gt;&gt;</a> ";
        var markup = firstPageLink + prevPageLink;
        var maxLinks = (this.pageLinksStart+pageLinksLength < this._totalPages) ?
            this.pageLinksStart+pageLinksLength-1 : this._totalPages;
        for(i=this.pageLinksStart; i<=maxLinks; i++) {
             if(i != this.pageCurrent) {
                markup += " <a href=\"#\" class=\"" + YAHOO.widget.DataTable.CLASS_PAGELINK + "\">" + i + "</a> ";
            }
            else {
                markup += " <span class=\"" + YAHOO.widget.DataTable.CLASS_CURRENTPAGE + "\">" + i + "</span>";
            }
        }
        markup += nextPageLink + lastPageLink;

        // Markup for rows-per-page dropdowns
        var dropdown = this.rowsPerPageDropdown;
        var select1, select2;
        if(dropdown && (dropdown.constructor == Array) && (dropdown.length > 0)) {
            select1 = document.createElement("select");
            select1.className = YAHOO.widget.DataTable.CLASS_PAGESELECT;
            select2 = document.createElement("select");
            select2.className = YAHOO.widget.DataTable.CLASS_PAGESELECT;
            
            for(i=0; i<dropdown.length; i++) {
                var option1 = document.createElement("option");
                var option2 = document.createElement("option");
                option1.value = dropdown[i];
                option2.value = dropdown[i];
                option1.innerHTML = dropdown[i];
                option2.innerHTML = dropdown[i];

                if(this.rowsPerPage === dropdown[i]) {
                    option1.selected = true;
                    option2.selected = true;
                }
                option1 = select1.appendChild(option1);
                option2 = select2.appendChild(option2);
            }
        }

        // Populate each pager container with markup
        if(!this.pagers || (this.pagers.length === 0)) {
            var pager1 = document.createElement("span");
            pager1.className = YAHOO.widget.DataTable.CLASS_PAGELINKS;
            
            var pager2 = document.createElement("span");
            pager2.className = YAHOO.widget.DataTable.CLASS_PAGELINKS;

            pager1 = this._elContainer.insertBefore(pager1, this._elTable);
            select1 = (select1 === undefined) ? null :
                    this._elContainer.insertBefore(select1, this._elTable);
            select2 = (select2 === undefined) ? null :
                    this._elContainer.insertBefore(select2, this._elTable.nextSibling);
            pager2 = this._elContainer.insertBefore(pager2, this._elTable.nextSibling);
            this.pagers = [
                {links:pager1,select:select1},
                {links:pager2,select:select2}
            ];
        }
        for(i=0; i<this.pagers.length; i++) {
            this.pagers[i].links.innerHTML = markup;
            YAHOO.util.Event.purgeElement(this.pagers[i].links);
            if(this.pagers[i].select) {
                YAHOO.util.Event.purgeElement(this.pagers[i].select);
            }
            this.pagers[i].innerHTML = markup;
            YAHOO.util.Event.addListener(this.pagers[i].links,"click",this._onPagerClick,this);
            if(this.pagers[i].select) {
                YAHOO.util.Event.addListener(this.pagers[i].select,"change",this._onPagerSelect,this);
            }
        }
    }
    this.fireEvent("paginateEvent");
};

/**
 * Sort given column.
 *
 * @method sortColumn
 * @param oColumn {YAHOO.widget.Column} Column to sort. TODO: accept the TH or TH.key
 */
YAHOO.widget.DataTable.prototype.sortColumn = function(oColumn) {
    if(!oColumn) {
        return;
    }
    if(!oColumn instanceof YAHOO.widget.Column) {
        //TODO: Figure out the column based on TH ref or TH.key
        return;
    }
    if(oColumn.sortable) {
        // What is the default sort direction?
        var sortDir = (oColumn.sortOptions && oColumn.sortOptions.defaultOrder) ? oColumn.sortOptions.defaultOrder : "asc";

        //TODO: what if column doesn't have key?
        // Is this column sorted already?
        if(oColumn.key && this.sortedBy && (this.sortedBy.colKey == oColumn.key)) {
            if(this.sortedBy.dir) {
                sortDir = (this.sortedBy.dir == "asc") ? "desc" : "asc";
            }
            else {
                sortDir = (sortDir == "asc") ? "desc" : "asc";
            }
        }
        else if(!this.sortedBy) {
            this.sortedBy = {};
        }

        // Define the sort handler function based on the direction
        var sortFnc = null;
        if((sortDir == "desc") && oColumn.sortOptions && oColumn.sortOptions.descFunction) {
            sortFnc = oColumn.sortOptions.descFunction;
        }
        else if((sortDir == "asc") && oColumn.sortOptions && oColumn.sortOptions.ascFunction) {
            sortFnc = oColumn.sortOptions.ascFunction;
        }

        // Custom function was not provided so use the built-in sorter
        // ONLY IF column key is defined
        // TODO: use diff default functions based on column data type
        // TODO: nested/cumulative/hierarchical sorting
        if(!sortFnc && oColumn.key) {
            var sorted;
            sortFnc = function(a, b) {
                if(sortDir == "desc") {
                    sorted = YAHOO.util.Sort.compareDesc(a[oColumn.key],b[oColumn.key]);
                    if(sorted === 0) {
                        return YAHOO.util.Sort.compareDesc(a.id,b.id);
                    }
                    else {
                        return sorted;
                    }
                }
                else {
                    sorted = YAHOO.util.Sort.compareAsc(a[oColumn.key],b[oColumn.key]);
                    if(sorted === 0) {
                        return YAHOO.util.Sort.compareAsc(a.id,b.id);
                    }
                    else {
                        return sorted;
                    }
                }
            };
        }

        if(sortFnc) {
            // Do the actual sort
            this._oRecordSet.sort(sortFnc);

            // Update the UI
            this.paginateRows();

            // Update classes
            YAHOO.util.Dom.removeClass(this.sortedBy._id,YAHOO.widget.DataTable.CLASS_SORTEDBYASC);
            YAHOO.util.Dom.removeClass(this.sortedBy._id,YAHOO.widget.DataTable.CLASS_SORTEDBYDESC);
            var newClass = (sortDir == "asc") ? YAHOO.widget.DataTable.CLASS_SORTEDBYASC : YAHOO.widget.DataTable.CLASS_SORTEDBYDESC;
            YAHOO.util.Dom.addClass(oColumn.getId(), newClass);

            // Keep track of currently sorted column
            this.sortedBy.colKey = oColumn.key;
            this.sortedBy.dir = sortDir;
            this.sortedBy._id = oColumn.getId();

            this.fireEvent("columnSortEvent",{column:oColumn,dir:sortDir});
        }
    }
    else {
        //TODO
        YAHOO.log("Column is not sortable", "info", this.toString());
    }
};

/**
 * Shows editor for given cell.
 *
 * @method editCell
 */
YAHOO.widget.DataTable.prototype.editCell = function(elCell) {
    if(elCell && !isNaN(elCell.columnIndex)) {
        var column = this._oColumnSet.keys[elCell.columnIndex];
        if(column && column.editor) {
            this.activeEditor = column.getEditor(elCell,this._oRecordSet.getRecord(elCell.parentNode.recordId));
        }
        this._bFocused = true;
        this.fireEvent("editorShowEvent",{target:elCell,column:column});
    }
};

/**
 * Formats given cell.
 *
 * @method formatCell
 */
YAHOO.widget.DataTable.prototype.formatCell = function(elCell) {
    if(elCell && !isNaN(elCell.columnIndex)) {
        var column = this._oColumnSet.keys[elCell.columnIndex];
        column.format(elCell,this._oRecordSet.getRecord(elCell.parentNode.recordId));
        this.fireEvent("cellFormatEvent", {el:elCell});
    }
};


/////////////////////////////////////////////////////////////////////////////
//
// Public Custom Event Handlers
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Overridable custom event handler to sort column.
 *
 * @method onEventSortColumn
 * @param oArgs.event {HTMLEvent} Event object.
 * @param oArgs.target {HTMLElement} Target element.
 */
YAHOO.widget.DataTable.prototype.onEventSortColumn = function(oArgs) {
    var evt = oArgs.event;
    var target = oArgs.target;
    YAHOO.util.Event.stopEvent(evt);
    
    //TODO: traverse DOM to find a columnIndex, incl safety net if none exists
    var columnIndex = target.columnIndex;
    if(!isNaN(columnIndex)) {
        this.sortColumn(this._oColumnSet.keys[columnIndex]);
    }
};

/**
 * Overridable custom event handler to select row.
 *
 * @method onEventSelectRow
 * @param oArgs.event {HTMLEvent} Event object.
 * @param oArgs.target {HTMLElement} Target element.
 */
YAHOO.widget.DataTable.prototype.onEventSelectRow = function(oArgs) {
    var i;
    var evt = oArgs.event;
    var target = oArgs.target;

    //TODO: add a safety net in case TR is never reached
    // Walk up the DOM until we get to the TR
    while(target.tagName.toLowerCase() != "tr") {
        target = target.parentNode;
    }

    if(this.isSelected(target)) {
        this.unselect(target);
    }
    else {
        if(this.rowSingleSelect && !evt.ctrlKey && !evt.shiftKey) {
            this.unselectAllRows();
        }
        if(evt.shiftKey) {
            var startRow = this._lastSelected;
            if(startRow && this.isSelected(startRow)) {
                this.unselectAllRows();
                if(startRow.sectionRowIndex < target.sectionRowIndex) {
                    for(i=startRow.sectionRowIndex; i<=target.sectionRowIndex; i++) {
                        this.select(this._elBody.rows[i]);
                    }
                }
                else {
                    for(i=target.sectionRowIndex; i<=startRow.sectionRowIndex; i++) {
                        this.select(this._elBody.rows[i]);
                    }
                }
            }
            else {
                this.select(target);
            }
        }
        else {
            this.select(target);
        }
    }
};

/**
 * Overridable custom event handler to select cell.
 *
 * @method onEventSelectCell
 * @param oArgs.event {HTMLEvent} Event object.
 * @param oArgs.target {HTMLElement} Target element.
 */
YAHOO.widget.DataTable.prototype.onEventSelectCell = function(oArgs) {
    var evt = oArgs.event;
    var target = oArgs.target;

    //TODO: add a safety net in case TD is never reached
    // Walk up the DOM until we get to the TD
    while(target.tagName.toLowerCase() != "td") {
        target = target.parentNode;
    }

    if(this.isSelected(target)) {
        this.unselect(target);
    }
    else {
        if(this.rowSingleSelect && !evt.ctrlKey) {
            this.unselectAllCells();
        }
        this.select(target);
    }
};

/**
 * Overridable custom event handler to format cell.
 *
 * @method onEventFormatCell
 * @param oArgs.event {HTMLEvent} Event object.
 * @param oArgs.target {HTMLElement} Target element.
 */
YAHOO.widget.DataTable.prototype.onEventFormatCell = function(oArgs) {
    var evt = oArgs.event;
    var element = oArgs.target;

    //TODO: add a safety net in case TD is never reached
    // Walk up the DOM until we get to the TD
    while(element.tagName.toLowerCase() != "td") {
        element = element.parentNode;
    }

    this.formatCell(element);
};

/**
 * Overridable custom event handler to highlight cell.
 *
 * @method onEventHighlightCell
 * @param oArgs.event {HTMLEvent} Event object.
 * @param oArgs.target {HTMLElement} Target element.
 */
YAHOO.widget.DataTable.prototype.onEventHighlightCell = function(oArgs) {
    var evt = oArgs.event;
    var element = oArgs.target;

    //TODO: add a safety net in case TD is never reached
    // Walk up the DOM until we get to the TD
    while(element.tagName.toLowerCase() != "td") {
        element = element.parentNode;
    }
    this.highlight(element);
};

/**
 * Overridable custom event handler to unhighlight cell.
 *
 * @method onEventUnhighlightCell
 * @param oArgs.event {HTMLEvent} Event object.
 * @param oArgs.target {HTMLElement} Target element.
 */
YAHOO.widget.DataTable.prototype.onEventUnhighlightCell = function(oArgs) {
    var evt = oArgs.event;
    var element = oArgs.target;

    //TODO: add a safety net in case TD is never reached
    // Walk up the DOM until we get to the TD
    while(element.tagName.toLowerCase() != "td") {
        element = element.parentNode;
    }
    
    this.unhighlight(element);
};
/**
 * Overridable custom event handler to edit cell.
 *
 * @method onEventEditCell
 * @param oArgs.event {HTMLEvent} Event object.
 * @param oArgs.target {HTMLElement} Target element.
 */
YAHOO.widget.DataTable.prototype.onEventEditCell = function(oArgs) {
    var evt = oArgs.event;
    var element = oArgs.target;

    //TODO: add a safety net in case TD is never reached
    // Walk up the DOM until we get to the TD
    while(element.tagName.toLowerCase() != "td") {
        element = element.parentNode;
    }

    this.editCell(element);
};

/**
 * Handles data return for adding new rows to table, including updating pagination.
 *
 * @method onDataReturnPaginateRows
 * @param sRequest {String} Original request.
 * @param oResponse {Object} Response object.
 */
YAHOO.widget.DataTable.prototype.onDataReturnPaginateRows = function(sRequest, oResponse) {
    this.fireEvent("dataReturnEvent", {request:sRequest,response:oResponse});
    
    var ok = this.doBeforeLoadData(sRequest, oResponse);
    if(ok) {
        // Update the RecordSet from the response
        var newRecords = this._oRecordSet.append(oResponse);
        if(newRecords) {
            // Update markup
            this.paginateRows();
            YAHOO.log("Data returned for " + newRecords.length + " rows","info",this.toString());
        }
    }
};

/**
 * Handles data return for adding new rows to bottom of table.
 *
 * @method onDataReturnAppendRows
 * @param sRequest {String} Original request.
 * @param oResponse {Object} Response object.
 */
YAHOO.widget.DataTable.prototype.onDataReturnAppendRows = function(sRequest, oResponse) {
    this.fireEvent("dataReturnEvent", {request:sRequest,response:oResponse});
    
    var ok = this.doBeforeLoadData(sRequest, oResponse);
    if(ok) {
        // Update the RecordSet from the response
        var newRecords = this._oRecordSet.append(oResponse);
        if(newRecords) {
            // Update markup
            this.appendRows(newRecords);
            YAHOO.log("Data returned for " + newRecords.length + " rows","info",this.toString());
        }
    }
};

/**
 * Handles data return for inserting new rows to top of table.
 *
 * @method onDataReturnInsertRows
 * @param sRequest {String} Original request.
 * @param oResponse {Object} Response object.
 */
YAHOO.widget.DataTable.prototype.onDataReturnInsertRows = function(sRequest, oResponse) {
    this.fireEvent("dataReturnEvent", {request:sRequest,response:oResponse});
    
    var ok = this.doBeforeLoadData(sRequest, oResponse);
    if(ok) {
        // Update the RecordSet from the response
        var newRecords = this._oRecordSet.insert(oResponse);
        if(newRecords) {
            // Update markup
            this.insertRows(newRecords);
            YAHOO.log("Data returned for " + newRecords.length + " rows","info",this.toString());
        }
    }
};

/**
 * Handles data return for replacing all existing of table with new rows.
 *
 * @method onDataReturnReplaceRows
 * @param sRequest {String} Original request.
 * @param oResponse {Object} Response object.
 */
YAHOO.widget.DataTable.prototype.onDataReturnReplaceRows = function(sRequest, oResponse) {
    this.fireEvent("dataReturnEvent", {request:sRequest,response:oResponse});
    
    var ok = this.doBeforeLoadData(sRequest, oResponse);
    if(ok) {
        // Update the RecordSet from the response
        var newRecords = this._oRecordSet.replace(oResponse);
        if(newRecords) {
            this.replaceRows(newRecords);
            YAHOO.log("Data returned for " + newRecords.length + " rows","info",this.toString());
        }
    }
};


/****************************************************************************/
/****************************************************************************/
/****************************************************************************/

/**
 * The ColumnSet class defines and manages a DataTable's Columns,
 * including nested hierarchies and access to individual Column instances.
 *
 * @class ColumnSet
 * @uses YAHOO.util.EventProvider
 * @constructor
 * @param aHeaders {Object[]} Array of object literals that define header cells.
 */
YAHOO.widget.ColumnSet = function(aHeaders) {
//TODO: break out nested functions into private methods
    this._sName = "instance" + YAHOO.widget.ColumnSet._nCount;

    // Top-down tree representation of all Columns
    var tree = [];
    // Flat representation of all Columns
    var flat = [];
    // Flat representation of only Columns that display data
    var keys = [];
    // ID index of nested parent heirarchies for HEADERS attribute
    var headers = [];

    var nodelevel = -1;

    // Internal recursive function to parse Columns out of object literal defs
    var parseColumns = function(nodeList, parent) {
        nodelevel++;
        // A node level is an array of Columns
        if(!tree[nodelevel]) {
            tree[nodelevel] = [];
        }

        // Determine depth of descendants at this level for node's rowspan
        var nodeLevelMaxChildren = 0;
        var recurseChildren = function(nodeList) {
            var tmpMax = 0;
            for(var i=0; i<nodeList.length; i++) {
                if(nodeList[i].children) {
                    tmpMax++;
                    recurseChildren(nodeList[i].children);
                }
                if(tmpMax > nodeLevelMaxChildren) {
                    nodeLevelMaxChildren = tmpMax;
                }
            }
        };
        recurseChildren(nodeList);

        // Parse each node for attributes and any children
        for(var j=0; j<nodeList.length; j++) {
            // Instantiate a Column for each node
            var oColumn = new YAHOO.widget.Column(nodeList[j]);
            flat.push(oColumn);
            
            // Assign parent, if applicable
            if(parent) {
                oColumn._parent = parent;
            }

            // Start with default values
            oColumn._rowspan = 1;
            oColumn._colspan = 1;

            // Column may have children
            if(nodeList[j].children) {
                var children = nodeList[j].children;
                var length = children.length;
                
                // Cascade certain properties to children if not defined on their own
                for(var k=0; k<length; k++) {
                    var child = children[k];
                    if(oColumn.className && (child.className === undefined)) {
                        child.className = oColumn.className;
                    }
                    if(oColumn.editor && (child.editor === undefined)) {
                        child.editor = oColumn.editor;
                    }
                    if(oColumn.formatter && (child.formatter === undefined)) {
                        child.formatter = oColumn.formatter;
                    }
                    if(oColumn.parser && (child.parser === undefined)) {
                        child.parser = oColumn.parser;
                    }
                    if(oColumn.resizeable && (child.resizeable === undefined)) {
                        child.resizeable = oColumn.resizeable;
                    }
                    if(oColumn.type && (child.type === undefined)) {
                        child.type = oColumn.type;
                    }
                    if(oColumn.width && (child.width === undefined)) {
                        child.width = oColumn.width;
                    }
                }
                
                // Children increase colspan of the Column
                oColumn._colspan = length;

                // Children increase colspan of the Column's parent
                if (parent && parent._colspan) {
                    parent._colspan += length-1;
                    parent._children = [];
                    parent._children.push(oColumn);
                }
                
                // Children must also be parsed
                if(!tree[nodelevel+1]) {
                    tree[nodelevel+1] = [];
                }
               parseColumns(children, oColumn);
            }
            
            // This Column does not have children,
            // but other Columns at this level do
            else if(nodeLevelMaxChildren > 0) {
                // Children of siblings increase the rowspan of the Column
                oColumn._rowspan += nodeLevelMaxChildren;
                //if(oColumn.key) {
                    oColumn._index = keys.length;
                    keys.push(oColumn);
                //}
            }
            // This entire node level does not have any children
            else {
                //if(oColumn.key) {
                    oColumn._index = keys.length;
                    keys.push(oColumn);
                //}
            }

            // Add the Column to the top-down tree
            tree[nodelevel].push(oColumn);
        }
        nodelevel--;
    };

    // Do the parsing
    if(aHeaders.length > 0) {
        parseColumns(aHeaders);
    }

    // Store header nesting in an array
    var recurseAncestors = function(i, oColumn) {
        headers[i].push(oColumn._id);
        if(oColumn._parent) {
            recurseAncestors(i, oColumn._parent);
        }
    };
    for(var i=0; i<keys.length; i++) {
        headers[i] = [];
        recurseAncestors(i, keys[i]);
        headers[i] = headers[i].reverse();
        headers[i] = headers[i].join(" ");
    }

    this.tree = tree;
    this.flat = flat;
    this.keys = keys;
    this.headers = headers;
    
    YAHOO.widget.ColumnSet._nCount++;
    YAHOO.log("ColumnSet initialized", "info", this.toString());
};

/////////////////////////////////////////////////////////////////////////////
//
// Public member variables
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Internal class variable to index multiple data table instances.
 *
 * @property _nCount
 * @type number
 * @private
 * @static
 */
YAHOO.widget.ColumnSet._nCount = 0;

/**
 * Unique instance name.
 *
 * @property _sName
 * @type String
 * @private
 */
YAHOO.widget.ColumnSet.prototype._sName = null;

/////////////////////////////////////////////////////////////////////////////
//
// Public member variables
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Top-down tree representation of Column hierarchy.
 *
 * @property tree
 * @type YAHOO.widget.Column[]
 */
YAHOO.widget.ColumnSet.prototype.tree = null;

/**
 * Flattened representation of all Columns.
 *
 * @property flat
 * @type YAHOO.widget.Column[]
 * @default []
 */
YAHOO.widget.ColumnSet.prototype.flat = null;

/**
 * Array of Columns that map one-to-one to a table column.
 *
 * @property keys
 * @type YAHOO.widget.Column[]
 * @default []
 */
YAHOO.widget.ColumnSet.prototype.keys = null;

/**
 * ID index of nested parent heirarchies for HEADERS accessibility attribute.
 *
 * @property headers
 * @type String[]
 * @default []
 */
YAHOO.widget.ColumnSet.prototype.headers = null;

/////////////////////////////////////////////////////////////////////////////
//
// Public methods
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Public accessor to the unique name of the ColumnSet instance.
 *
 * @method toString
 * @return {String} Unique name of the ColumnSet instance.
 */

YAHOO.widget.ColumnSet.prototype.toString = function() {
    return "ColumnSet " + this._sName;
};

/****************************************************************************/
/****************************************************************************/
/****************************************************************************/

/**
 * The Column class defines and manages attributes of DataTable Columns
 *
 *
 * @class Column
 * @constructor
 * @param oConfigs {Object} Object literal of configuration values.
 */
YAHOO.widget.Column = function(oConfigs) {
    // Internal variables
    this._id = "yui-dtcol"+YAHOO.widget.Column._nCount;
    
    // Object literal defines Column attributes
    if(typeof oConfigs == "object") {
        for(var sConfig in oConfigs) {
            if(sConfig) {
                this[sConfig] = oConfigs[sConfig];
            }
        }
    }
    
    YAHOO.widget.Column._nCount++;
};

/////////////////////////////////////////////////////////////////////////////
//
// Private member variables
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Internal instance counter.
 *
 * @property _nCount
 * @type Number
 * @static
 * @default 0
 */
YAHOO.widget.Column._nCount = 0;


/**
 * Unique ID, also assigned as DOM ID.
 *
 * @property _id
 * @type String
 * @private
 */
YAHOO.widget.Column.prototype._id = null;

/**
 * Reference to Column's index within its ColumnSet's key array, or null if not applicable.
 *
 * @property _index
 * @type Number
 * @private
 */
YAHOO.widget.Column.prototype._index = null;

/**
 * Number of table cells the Column spans.
 *
 * @property _colspan
 * @type Number
 * @private
 */
YAHOO.widget.Column.prototype._colspan = 1;

/**
 * Number of table rows the Column spans.
 *
 * @property _rowspan
 * @type Number
 * @private
 */
YAHOO.widget.Column.prototype._rowspan = 1;

/**
 * Column's parent, or null.
 *
 * @property _parent
 * @type YAHOO.widget.Column
 * @private
 */
YAHOO.widget.Column.prototype._parent = null;

/**
 * Array of Column's chilren, or null.
 *
 * @property _children
 * @type YAHOO.widget.Column[]
 * @private
 */
YAHOO.widget.Column.prototype._children = null;

//TODO: clean these up

/**
 * Current offsetWidth of the Column (in pixels).
 *
 * @property _width
 * @type Number
 * @private
 */
YAHOO.widget.Column.prototype._width = null;

/**
 * Minimum width the Column can support (in pixels). Value is populated only if table
 * is fixedwidth, null otherwise.
 *
 * @property _minWidth
 * @type Number
 * @private
 */
YAHOO.widget.Column.prototype._minWidth = null;

/////////////////////////////////////////////////////////////////////////////
//
// Public member variables
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Associated database field, or null.
 *
 * @property key
 * @type String
 */
YAHOO.widget.Column.prototype.key = null;

/**
 * Text or HTML for display in Column's assocated TH element.
 *
 * @property text
 * @type String
 */
YAHOO.widget.Column.prototype.text = null;

/**
 * Data types: "string", "number", "date", "currency", "checkbox", "select",
 * "email", "link".
 *
 * @property type
 * @type String
 * @default "string"
 */
YAHOO.widget.Column.prototype.type = "string";

/**
 * Column head cell ABBR for accessibility.
 *
 * @property abbr
 * @type String
 */
YAHOO.widget.Column.prototype.abbr = null;

/**
 * Array of object literals that define children (nested headers) of a Column.
 *
 * @property children
 * @type Object[]
 */
YAHOO.widget.Column.prototype.children = null;

/**
 * Column width.
 *
 * @property width
 * @type String
 */
YAHOO.widget.Column.prototype.width = null;

/**
 * Custom CSS class to be applied to every cell in the Column.
 *
 * @property className
 * @type String
 */
YAHOO.widget.Column.prototype.className = null;

/**
 * Defines a custom format function for Column, otherwise default is used,
 * according to Column type.
 *
 * @property formatter
 * @type HTMLFunction
 */
YAHOO.widget.Column.prototype.formatter = null;

/**
 * Defines a custom parse function for Column, otherwise default is used,
 * according to Column type.
 *
 * @property parser
 * @type HTMLFunction
 */
YAHOO.widget.Column.prototype.parser = null;

/**
 * Defines the type of editor for Column, otherwise Column is not editable.
 *
 * @property editor
 * @type String
 */
YAHOO.widget.Column.prototype.editor = null;

/**
 * True if Column is resizeable, false otherwise.
 *
 * @property resizeable
 * @type Boolean
 * @default false
 */
YAHOO.widget.Column.prototype.resizeable = false;

/**
 * True if Column is sortable, false otherwise.
 *
 * @property sortable
 * @type Boolean
 * @default false
 */
YAHOO.widget.Column.prototype.sortable = false;

/**
 * Custom sort handler to arrange Column in descending order.
 *
 * @property sortOptions.descFunction
 * @type Function
 * @default null
 */
YAHOO.widget.Column.prototype.descFunction = null;

/**
 * Custom sort handler to arrange Column in ascending order.
 *
 * @property sortOptions.ascFunction
 * @type Function
 * @default null
 */
YAHOO.widget.Column.prototype.ascFunction = null;















/////////////////////////////////////////////////////////////////////////////
//
// Public methods
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Public accessor returns Column's ID string.
 *
 * @method getId
 * @return {String} Column's ID string.
 */
YAHOO.widget.Column.prototype.getId = function() {
    return this._id;
};

/**
 * Public accessor returns Column's colspan number.
 *
 * @method getColSpan
 * @return {Number} Column's colspan number.
 */
YAHOO.widget.Column.prototype.getColSpan = function() {
    return this._colspan;
};

/**
 * Public accessor returns Column's rowspan number.
 *
 * @method getRowSpan
 * @return {Number} Column's rowspan number.
 */
YAHOO.widget.Column.prototype.getRowSpan = function() {
    return this._rowspan;
};


/**
 * Outputs markup into the given TD based on given Record.
 *
 * @method format
 * @param elCell {HTMLElement} TD to format for display.
 * @param oRecord {YAHOO.widget.Record} Record that holds data for the row.
 * @return {HTML} Markup.
 */
YAHOO.widget.Column.prototype.format = function(elCell,oRecord) {
    var oData = (this.key) ? oRecord[this.key] : null;
    if(this.formatter) {
        this.formatter(elCell, oRecord, this, oData);
    }
    else {
        var type = this.type;
        var markup = "";
        var classname = "";
        switch(type) {
            case "checkbox":
                YAHOO.widget.Column.formatCheckbox(elCell, oRecord, this, oData);
                classname = YAHOO.widget.DataTable.CLASS_CHECKBOX;
                break;
            case "currency":
                YAHOO.widget.Column.formatCurrency(elCell, oRecord, this, oData);
                classname = YAHOO.widget.DataTable.CLASS_CURRENCY;
                break;
            case "date":
                YAHOO.widget.Column.formatDate(elCell, oRecord, this, oData);
                classname = YAHOO.widget.DataTable.CLASS_DATE;
                break;
            case "email":
                YAHOO.widget.Column.formatEmail(elCell, oRecord, this, oData);
                classname = YAHOO.widget.DataTable.CLASS_EMAIL;
                break;
            case "link":
                YAHOO.widget.Column.formatLink(elCell, oRecord, this, oData);
                classname = YAHOO.widget.DataTable.CLASS_LINK;
                break;
            case "number":
                YAHOO.widget.Column.formatNumber(elCell, oRecord, this, oData);
                classname = YAHOO.widget.DataTable.CLASS_NUMBER;
                break;
            case "select":
                YAHOO.widget.Column.formatSelect(elCell, oRecord, this, oData);
                classname = YAHOO.widget.DataTable.CLASS_SELECT;
                break;
           default:
                elCell.innerHTML = (oData) ? oData.toString() : "";
                //elCell.innerHTML = (oData) ? "<a href=\"#\">"+oData.toString()+"</a>" : "";
                classname = YAHOO.widget.DataTable.CLASS_STRING;
                break;
        }

        YAHOO.util.Dom.addClass(elCell, classname);
        if(this.className) {
            YAHOO.util.Dom.addClass(elCell, this.className);
        }
    }
    
    if(this.editor) {
        YAHOO.util.Dom.addClass(elCell,YAHOO.widget.DataTable.CLASS_EDITABLE);
    }
};


/**
 * Formats cells in Columns of type "checkbox".
 *
 * @method formatCheckbox
 * @param elCell {HTMLElement} Table cell element.
 * @param oRecord {YAHOO.widget.Record} Record instance.
 * @param oColumn {YAHOO.widget.Column} Column instance.
 * @param oData {Object} Data value for the cell, or null
 * @static
 */
YAHOO.widget.Column.formatCheckbox = function(elCell, oRecord, oColumn, oData) {
    var bChecked = oData;
    bChecked = (bChecked) ? " checked" : "";
    elCell.innerHTML = "<input type=\"checkbox\"" + bChecked +
            " class=\"" + YAHOO.widget.DataTable.CLASS_CHECKBOX + "\">";
};

/**
 * Formats cells in Columns of type "currency". Can be overridden for custom formatting.
 *
 * @method formatCurrency
 * @param elCell {HTMLElement} Table cell element.
 * @param oRecord {YAHOO.widget.Record} Record instance.
 * @param oColumn {YAHOO.widget.Column} Column instance.
 * @param oData {Object} Data value for the cell, or null
 * @static
 */
YAHOO.widget.Column.formatCurrency = function(elCell, oRecord, oColumn, oData) {
    // Make it dollars
    var nAmount = oData;
    var markup;
        if(nAmount) {
             markup = "$"+nAmount;

            // Normalize to the penny
            var dotIndex = markup.indexOf(".");
            if(dotIndex < 0) {
                markup += ".00";
            }
            else {
                while(dotIndex != markup.length-3) {
                    markup += "0";
                }
            }
        }
        else {
            markup = "";
        }
        elCell.innerHTML = markup;
};

/**
 * Formats cells in Columns of type "date".
 *
 * @method formatDate
 * @param elCell {HTMLElement} Table cell element.
 * @param oRecord {YAHOO.widget.Record} Record instance.
 * @param oColumn {YAHOO.widget.Column} Column instance.
 * @param oData {Object} Data value for the cell, or null
 * @static
 */
YAHOO.widget.Column.formatDate = function(elCell, oRecord, oColumn, oData) {
    var oDate = oData;
    if(oDate) {
        elCell.innerHTML = oDate.getMonth() + "/" + oDate.getDate()  + "/" + oDate.getFullYear();
    }
    else {
        elCell.innerHTML = "";
    }
};

/**
 * Formats cells in Columns of type "email".
 *
 * @method formatEmail
 * @param elCell {HTMLElement} Table cell element.
 * @param oRecord {YAHOO.widget.Record} Record instance.
 * @param oColumn {YAHOO.widget.Column} Column instance.
 * @param oData {Object} Data value for the cell, or null
 * @static
 */
YAHOO.widget.Column.formatEmail = function(elCell, oRecord, oColumn, oData) {
    var sEmail = oData;
    if(sEmail) {
        elCell.innerHTML = "<a href=\"mailto:" + sEmail + "\">" + sEmail + "</a>";
    }
    else {
        elCell.innerHTML = "";
    }
};

/**
 * Formats cells in Columns of type "link".
 *
 * @method formatLink
 * @param elCell {HTMLElement} Table cell element.
 * @param oRecord {YAHOO.widget.Record} Record instance.
 * @param oColumn {YAHOO.widget.Column} Column instance.
 * @param oData {Object} Data value for the cell, or null
 * @static
 */
YAHOO.widget.Column.formatLink = function(elCell, oRecord, oColumn, oData) {
    var sLink = oData;
    if(sLink) {
        elCell.innerHTML = "<a href=\"" + sLink + "\">" + sLink + "</a>";
    }
    else {
        elCell.innerHTML = "";
    }
};

/**
 * Formats cells in Columns of type "number".
 *
 * @method formatNumber
 * @param elCell {HTMLElement} Table cell element.
 * @param oRecord {YAHOO.widget.Record} Record instance.
 * @param oColumn {YAHOO.widget.Column} Column instance.
 * @param oData {Object} Data value for the cell, or null
 * @static
 */
YAHOO.widget.Column.formatNumber = function(elCell, oRecord, oColumn, oData) {
    var nNumber = oData;
    if(nNumber) {
        elCell.innerHTML = nNumber.toString();
    }
    else {
        elCell.innerHTML = "";
    }
};

/**
 * Formats cells in Columns of type "select".
 *
 * @method formatSelect
 * @param elCell {HTMLElement} Table cell element.
 * @param oRecord {YAHOO.widget.Record} Record instance.
 * @param oColumn {YAHOO.widget.Column} Column instance.
 * @param oData {Object} Data value for the cell, or null
 * @static
 */
YAHOO.widget.Column.formatSelect = function(elCell, oRecord, oColumn, oData) {
    var selectedValue = oData;
    var options = oColumn.selectOptions;

    var markup = "<select>";
    if(options) {
        for(var i=0; i<options.length; i++) {
            var option = options[i];
            markup += "<option value=\"" + option + "\"";
            if(selectedValue === option) {
                markup += " selected";
            }
            markup += ">" + option + "</option>";
        }
    }
    else {
        if(selectedValue) {
            markup += "<option value=\"" + selectedValue + "\" selected>" + selectedValue + "</option>";
        }
    }
    markup += "</select>";
    elCell.innerHTML = markup;
};

/**
 * Takes innerHTML from TD and parses out data for storage in RecordSet.
 *
 * @method parse
 * @param sMarkup {String} The TD's innerHTML value.
 * @return {Object} Data.
 */
YAHOO.widget.Column.prototype.parse = function(sMarkup) {
    if(this.parser) {
        return this.parser(sMarkup);
    }
    else {
        var data = null;
        switch(this.type) {
            case "checkbox":
                data = YAHOO.widget.Column.parseCheckbox(sMarkup);
                break;
            case "currency":
                data = YAHOO.widget.Column.parseCurrency(sMarkup);
                break;
            case "date":
                data = YAHOO.widget.Column.parseDate(sMarkup);
                break;
            case "number":
                data = YAHOO.widget.Column.parseNumber(sMarkup);
                break;
            case "select":
                data = YAHOO.widget.Column.parseSelect(sMarkup);
                break;
           default:
                if(sMarkup) {
                    data = sMarkup;
                }
                break;
        }
        return data;
    }
};

/**
 * Default parse function for Columns of type "checkbox" takes markup and
 * extracts data. Can be overridden for custom parsing.
 *
 * @method parseCheckbox
 * @param sMarkup
 * @return {bChecked} True if checkbox is checked.
 */
YAHOO.widget.Column.parseCheckbox = function(sMarkup) {
    return (sMarkup.indexOf("checked") < 0) ? false : true;
};

/**
 * Default parse function for Columns of type "currency" takes markup and
 * extracts data. Can be overridden for custom parsing.
 *
 * @method parseCurrency
 * @param sMarkup
 * @return {nAmount} Floating point amount.
 */
YAHOO.widget.Column.parseCurrency = function(sMarkup) {
    return parseFloat(sMarkup.substring(1));
};

/**
 * Default parse function for Columns of type "date" takes markup and extracts
 * data. Can be overridden for custom parsing.
 *
 * @method parseDate
 * @param sMarkup
 * @return {oDate} Date instance.
 */
YAHOO.widget.Column.parseDate = function(sMarkup) {
    var mm = sMarkup.substring(0,sMarkup.indexOf("/"));
    sMarkup = sMarkup.substring(sMarkup.indexOf("/")+1);
    var dd = sMarkup.substring(0,sMarkup.indexOf("/"));
    var yy = sMarkup.substring(sMarkup.indexOf("/")+1);
    return new Date(yy, mm, dd);
};

/**
 * Default parse function for Columns of type "number" takes markup and extracts
 * data. Can be overridden for custom parsing.
 *
 * @method parseNumber
 * @param sMarkup
 * @return {nNumber} Number.
 */
YAHOO.widget.Column.parseNumber = function(sMarkup) {
    return parseFloat(sMarkup);
};

/**
 * Default parse function for Columns of type "select" takes markup and extracts
 * data. Can be overridden for custom parsing.
 *
 * @method parseSelect
 * @param sMarkup
 * @return {sValue} Value of selected option.
 */
YAHOO.widget.Column.parseSelect = function(sMarkup) {
    //return (sMarkup.indexOf("checked") < 0) ? false : true;
};

/**
 * Outputs editor markup into the given TD based on given Record.
 *
 * @method showEditor
 * @param elCell {HTMLElement} The cell to edit.
 * @param oRecord {YAHOO.widget.Record} The DataTable Record of the cell.
 * @return YAHOO.widget.ColumnEditor
 */
YAHOO.widget.Column.prototype.getEditor = function(elCell, oRecord) {
//Sync up the arg signature for ColumnEditor constructor and show()
    var oEditor = this.editor;
    if(oEditor.constructor == String) {
        oEditor = new YAHOO.widget.ColumnEditor(this.editor);
        oEditor.show(elCell, oRecord, this);
        this.editor = oEditor;
    }
    else if(oEditor instanceof YAHOO.widget.ColumnEditor) {
        oEditor.show(elCell, oRecord, this);
    }
    return oEditor;
};


/****************************************************************************/
/****************************************************************************/
/****************************************************************************/

/**
 * The ColumnEditor defines and manages inline editing functionality for a
 * DataTable Column.
 *
 * @class ColumnEditor
 * @constructor
 * @param elCell {HTMLElement} The cell to edit.
 * @param oRecord {YAHOO.widget.Record} The DataTable Record of the cell.
 * @param oColumn {YAHOO.widget.Column} The DataTable Column of the cell.
 * @parem sType {String} Type identifier
 */
YAHOO.widget.ColumnEditor = function(sType) {
    this.type = sType;

    //TODO: make sure ColumnEditors get destroyed if widget gets destroyed
    // Works better to attach ColumnEditor to document.body
    // rather than the DataTable container
    // elTable comes in as a cell. Traverse up DOM to find the table.
    // TODO: safety net in case table is never found.
    //while(elCell.nodeName.toLowerCase() != "table") {
    //    elCell = elCell.parentNode;
    //}
    //this.tableContainer = elCell.parentNode;
    
    var container = document.body.appendChild(document.createElement("div"));//this.tableContainer.appendChild(document.createElement("div"));
    container.style.position = "absolute";
    container.style.zIndex = 9000;
    container.id = "yui-dt-coled" + YAHOO.widget.ColumnEditor._nCount;
    this.container = container;

    YAHOO.util.Dom.addClass(this.container, 'yui-dt-coled-' + this.type);
    switch(this.type) {
        case "textbox":
            this.createTextboxEditor();
            break;
        case "textarea":
            this.createTextareaEditor();
            break;
        default:
            break;
    }

    YAHOO.widget.ColumnEditor._nCount++;
};



/////////////////////////////////////////////////////////////////////////////
//
// Private member variables
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Internal instance counter.
 *
 * @property _nCount
 * @type Number
 * @static
 * @default 0
 */
YAHOO.widget.ColumnEditor._nCount =0;

/////////////////////////////////////////////////////////////////////////////
//
// Public member variables
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Reference to the container DOM element for the ColumnEditor.
 *
 * @property container
 * @type HTMLElement
 */
YAHOO.widget.ColumnEditor.prototype.container = null;

/**
 * Reference to the ColumnEditor's Column instance.
 *
 * @property column
 * @type YAHOO.widget.Column
 */
YAHOO.widget.ColumnEditor.prototype.column = null;

/**
 * Type of editor: "textbox", etc.
 *
 * @property type
 * @type String
 */
YAHOO.widget.ColumnEditor.prototype.type = null;



/**
 * Reference to form element(s) of the ColumnEditor.
 *
 * @property input
 * @type HTMLElement || HTMLElement[]
 */
YAHOO.widget.ColumnEditor.prototype.input = null;

/////////////////////////////////////////////////////////////////////////////
//
// Public methods
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Shows ColumnEditor.
 *
 * @method show
 * @param elCell {HTMLElement} The cell to edit.
 * @param oRecord {YAHOO.widget.Record} The DataTable Record of the cell.
 * @param oColumn {YAHOO.widget.Column} The DataTable Column of the cell.
 */
YAHOO.widget.ColumnEditor.prototype.show = function(elCell, oRecord, oColumn) {
    this.cell = elCell;
    this.record = oRecord;
    this.column = oColumn;
    switch(this.type) {
        case "textbox":
            this.showTextboxEditor(elCell, oRecord, oColumn);
            break;
        case "textarea":
            this.showTextareaEditor(elCell, oRecord, oColumn);
            break;
        default:
            break;
    }
};

/**
 * Returns ColumnEditor data value.
 *
 * @method getValue
 * @return Object
 */
YAHOO.widget.ColumnEditor.prototype.getValue = function() {
    var value;
    switch(this.type) {
        case "textbox":
            value = this.getTextboxEditorValue();
            break;
        case "textarea":
            value = this.getTextareaEditorValue();
            break;
        default:
            break;
    }
    return value;
};

/**
 * Creates a textbox editor in the DOM.
 *
 * @method createTextboxEditor
 * @return {HTML} ???
 */
YAHOO.widget.ColumnEditor.prototype.createTextboxEditor = function() {
    var elTextbox = this.container.appendChild(document.createElement("input"));
    // For FF bug 236791
    elTextbox.setAttribute("autocomplete","off");
    this.input = elTextbox;
};

/**
 * Creates a textarea editor in the DOM.
 *
 * @method createTextareaEditor
 * @return {HTML} ???
 */
YAHOO.widget.ColumnEditor.prototype.createTextareaEditor = function() {
    var elTextarea = this.container.appendChild(document.createElement("textarea"));
    this.input = elTextarea;
};

/**
 * Shows ColumnEditor
 *
 * @method showTextboxEditor
 * @param elCell {HTMLElement} The cell to edit.
 * @param oRecord {YAHOO.widget.Record} The DataTable Record of the cell.
 * @param oColumn {YAHOO.widget.Column} The DataTable Column of the cell.
 */
YAHOO.widget.ColumnEditor.prototype.showTextboxEditor = function(elCell, oRecord, oColumn) {
    // Size and value
    this.input.style.width = (parseInt(elCell.offsetWidth,10)-7) + "px";
    this.input.style.height = (parseInt(elCell.offsetHeight,10)-7) + "px";
    this.input.value = elCell.innerHTML;

    // Position and show
    var x,y;
    
    // Don't use getXY for Opera
    if(navigator.userAgent.toLowerCase().indexOf("opera") != -1) {
        x = elCell.offsetLeft;
        y = elCell.offsetTop;
        while(elCell.offsetParent) {
            x += elCell.offsetParent.offsetLeft;
            y += elCell.offsetParent.offsetTop;
            elCell = elCell.offsetParent;
        }
    } else {
        var xy = YAHOO.util.Dom.getXY(elCell);
        x = parseInt(YAHOO.util.Dom.getX(elCell),10);//xy[0] + 1;
        y = parseInt(YAHOO.util.Dom.getY(elCell),10);//xy[1] + 1;
    }
    this.container.style.left = x + "px";
    this.container.style.top = y + "px";
    this.container.style.display = "block";

    this.input.tabIndex = 0;
    this.input.focus();
    this.input.select();
};

/**
 * Shows ColumnEditor
 *
 * @method showTextareaEditor
 * @param elCell {HTMLElement} The cell to edit.
 * @param oRecord {YAHOO.widget.Record} The DataTable Record of the cell.
 * @param oColumn {YAHOO.widget.Column} The DataTable Column of the cell.
 */
YAHOO.widget.ColumnEditor.prototype.showTextareaEditor = function(elCell, oRecord, oColumn) {
    // Size and value
    this.input.style.width = (parseInt(elCell.offsetWidth,10)-7) + "px";
    this.input.style.height = 4*(parseInt(elCell.offsetHeight,10)-7) + "px";
    this.input.value = elCell.innerHTML;

    // Position and show
    var x,y;

    // Don't use getXY for Opera
    if(navigator.userAgent.toLowerCase().indexOf("opera") != -1) {
        x = elCell.offsetLeft;
        y = elCell.offsetTop;
        while(elCell.offsetParent) {
            x += elCell.offsetParent.offsetLeft;
            y += elCell.offsetParent.offsetTop;
            elCell = elCell.offsetParent;
        }
    } else {
        var xy = YAHOO.util.Dom.getXY(elCell);
        x = parseInt(YAHOO.util.Dom.getX(elCell),10);//xy[0] + 1;
        y = parseInt(YAHOO.util.Dom.getY(elCell),10);//xy[1] + 1;
    }
    this.container.style.left = x + "px";
    this.container.style.top = y + "px";
    this.container.style.display = "block";

    this.input.tabIndex = 0;
    this.input.focus();
    this.input.select();
};

/**
 * Hides ColumnEditor
 *
 * @method hide
 */
YAHOO.widget.ColumnEditor.prototype.hide = function() {
    this.input.tabIndex = -1;
    this.container.style.display = "none";
};

/**
 * Returns ColumnEditor value
 *
 * @method getTextboxEditorValue
 * @return String
 */
YAHOO.widget.ColumnEditor.prototype.getTextboxEditorValue = function() {
    return this.input.value;
};

/**
 * Returns ColumnEditor value
 *
 * @method getTextareaEditorValue
 * @return String
 */
YAHOO.widget.ColumnEditor.prototype.getTextareaEditorValue = function() {
    return this.input.value;
};

/****************************************************************************/
/****************************************************************************/
/****************************************************************************/

/**
 * Sort static utility to support Column sorting.
 *
 * @class Sort
 * @static
 */
YAHOO.util.Sort = {
    /////////////////////////////////////////////////////////////////////////////
    //
    // Public methods
    //
    /////////////////////////////////////////////////////////////////////////////

    /**
     * Comparator function for sort in ascending order. String sorting is case insensitive.
     *
     * @method compareAsc
     * @param a {object} First sort argument.
     * @param b {object} Second sort argument.
     */
    compareAsc: function(a, b) {
        //TODO: is typeof better or is constructor property better?
        if(a.constructor == String) {
            a = a.toLowerCase();
        }
        if(b.constructor == String) {
            b = b.toLowerCase();
        }
        if(a < b) {
            return -1;
        }
        else if (a > b) {
            return 1;
        }
        else {
            return 0;
        }
    },

    /**
     * Comparator function for sort in descending order. String sorting is case insensitive.
     *
     * @method compareDesc
     * @param a {object} First sort argument.
     * @param b {object} Second sort argument.
     */
    compareDesc: function(a, b) {
        //TODO: is typeof better or is constructor property better?
        if(a.constructor == String) {
            a = a.toLowerCase();
        }
        if(b.constructor == String) {
            b = b.toLowerCase();
        }
        if(a < b) {
            return 1;
        }
        else if (a > b) {
            return -1;
        }
        else {
            return 0;
        }
    }
};

/****************************************************************************/
/****************************************************************************/
/****************************************************************************/

/**
 * WidthResizer subclasses DragDrop to support resizeable Columns.
 *
 * @class WidthResizer
 * @extends YAHOO.util.DragDrop
 * @constructor
 * @param colElId {string} ID of the Column's TH element being resized
 * @param handleElId {string} ID of the handle element that causes the resize
 * @param sGroup {string} Group name of related DragDrop items
 */
YAHOO.util.WidthResizer = function(oDataTable, colId, handleId, sGroup, config) {
    if (colId) {
        this.cell = YAHOO.util.Dom.get(colId);
        this.init(handleId, sGroup, config);
        //this.initFrame();
        this.datatable = oDataTable;
        this.setYConstraint(0,0);
    }
    else {
        YAHOO.log("Column resizer could not be created due to invalid colElId","warn");
    }
};

if(YAHOO.util.DD) {
    YAHOO.extend(YAHOO.util.WidthResizer, YAHOO.util.DD);
}

/////////////////////////////////////////////////////////////////////////////
//
// Public DOM event handlers
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Handles mousedown events on the Column resizer.
 *
 * @method onMouseDown
 * @param e {string} The mousedown event
 */
YAHOO.util.WidthResizer.prototype.onMouseDown = function(e) {
    this.startWidth = this.cell.offsetWidth;
    this.startPos = YAHOO.util.Dom.getX(this.getDragEl());

    if(this.datatable.fixedwidth) {
        var cellText = YAHOO.util.Dom.getElementsByClassName(YAHOO.widget.DataTable.CLASS_COLUMNTEXT,"span",this.cell)[0];
        this.minWidth = cellText.offsetWidth + 6;
        var sib = this.cell.nextSibling;
        var sibCellText = YAHOO.util.Dom.getElementsByClassName(YAHOO.widget.DataTable.CLASS_COLUMNTEXT,"span",sib)[0];
        this.sibMinWidth = sibCellText.offsetWidth + 6;
//!!
        var left = ((this.startWidth - this.minWidth) < 0) ? 0 : (this.startWidth - this.minWidth);
        var right = ((sib.offsetWidth - this.sibMinWidth) < 0) ? 0 : (sib.offsetWidth - this.sibMinWidth);
        this.setXConstraint(left, right);
        YAHOO.log("cellstartwidth:" + this.startWidth,"time");
        YAHOO.log("cellminwidth:" + this.minWidth,"time");
        YAHOO.log("sibstartwidth:" + sib.offsetWidth,"time");
        YAHOO.log("sibminwidth:" + this.sibMinWidth,"time");
        YAHOO.log("l:" + left + " AND r:" + right,"time");
    }

};

/**
 * Handles mouseup events on the Column resizer.
 *
 * @method onMouseUp
 * @param e {string} The mouseup event
 */
YAHOO.util.WidthResizer.prototype.onMouseUp = function(e) {
    //TODO: replace the resizer where it belongs:
    var resizeStyle = YAHOO.util.Dom.get(this.handleElId).style;
    resizeStyle.left = "auto";
    resizeStyle.right = 0;
    resizeStyle.marginRight = "-6px";
    resizeStyle.width = "6px";
    //.yui-dt-headresizer {position:absolute;margin-right:-6px;right:0;bottom:0;width:6px;height:100%;cursor:w-resize;cursor:col-resize;}


    //var cells = this.datatable._elTable.tHead.rows[this.datatable._elTable.tHead.rows.length-1].cells;
    //for(var i=0; i<cells.length; i++) {
        //cells[i].style.width = "5px";
    //}

    //TODO: set new ColumnSet width values
    this.datatable.fireEvent("columnResizeEvent",{datatable:this.datatable,target:YAHOO.util.Dom.get(this.id)});
};

/**
 * Handles drag events on the Column resizer.
 *
 * @method onDrag
 * @param e {string} The drag event
 */
YAHOO.util.WidthResizer.prototype.onDrag = function(e) {
    var newPos = YAHOO.util.Dom.getX(this.getDragEl());//YAHOO.log("newpos:"+newPos,"warn");//YAHOO.util.Event.getPageX(e);
    var offsetX = newPos - this.startPos;//YAHOO.log("offset:"+offsetX,"warn");
    //YAHOO.log("startwidth:"+this.startWidth + " and offset:"+offsetX,"warn");
    var newWidth = this.startWidth + offsetX;//YAHOO.log("newwidth:"+newWidth,"warn");

    if(newWidth < this.minWidth) {
        newWidth = this.minWidth;
    }

    // Resize the Column
    var oDataTable = this.datatable;
    var elCell = this.cell;

    //YAHOO.log("newwidth" + newWidth,"warn");
    //YAHOO.log(newWidth + " AND "+ elColumn.offsetWidth + " AND " + elColumn.id,"warn");

    // Resize the other Columns
    if(oDataTable.fixedwidth) {
        // Moving right or left?
        var sib = elCell.nextSibling;
        //var sibIndex = elCell.index + 1;
        var sibnewwidth = sib.offsetWidth - offsetX;
        if(sibnewwidth < this.sibMinWidth) {
            sibnewwidth = this.sibMinWidth;
        }

        //TODO: how else to cycle through all the Columns without having to use an index property?
        for(var i=0; i<oDataTable._oColumnSet.length; i++) {
            if((i != elCell.index) &&  (i!=sibIndex)) {
                YAHOO.util.Dom.get(oDataTable._oColumnSet.keys[i].id).style.width = oDataTable._oColumnSet.keys[i].width + "px";
            }
        }
        sib.style.width = sibnewwidth;
        elCell.style.width = newWidth + "px";
        //oDataTable._oColumnSet.flat[sibIndex].width = sibnewwidth;
        //oDataTable._oColumnSet.flat[elCell.index].width = newWidth;

    }
    else {
        elCell.style.width = newWidth + "px";
    }
};




/****************************************************************************/
/****************************************************************************/
/****************************************************************************/

/**
 * A RecordSet defines and manages a set of Records.
 *
 * @class RecordSet
 * @param data {Object || Object[]} An object literal or an array of data.
 * @constructor
 */
YAHOO.widget.RecordSet = function(data) {
    // Internal variables
    this._nIndex = YAHOO.widget.RecordSet._nCount;
    this._records = [];
    
    if(data) {
        if(data.constructor == Array) {
            this.addRecords(data);
        }
        else if(data.constructor == Object) {
            this.addRecord(data);
        }
    }

    /**
     * Fired when a Record is updated with new data.
     *
     * @event recordUpdateEvent
     * @param oArgs.record {YAHOO.widget.Record} The Record instance.
     * @param oArgs.key {String} The Record key.
     * @param oArgs.newData {Object} New data.
     * @param oArgs.oldData {Object} Old data.
     *
     */
    this.createEvent("recordUpdateEvent");
    
    
    YAHOO.widget.RecordSet._nCount++;
    YAHOO.log("RecordSet initialized", "info", this.toString());
};

if(YAHOO.util.EventProvider) {
    YAHOO.augment(YAHOO.widget.RecordSet, YAHOO.util.EventProvider);
}
else {
    YAHOO.log("Missing dependency: YAHOO.util.EventProvider","error",this.toString());
}

/////////////////////////////////////////////////////////////////////////////
//
// Private member variables
//
/////////////////////////////////////////////////////////////////////////////
/**
 * Internal class variable to index multiple data table instances.
 *
 * @property _nCount
 * @type number
 * @private
 * @static
 */
YAHOO.widget.RecordSet._nCount = 0;

/**
 * Instance index.
 *
 * @property _nIndex
 * @type number
 * @private
 */
YAHOO.widget.RecordSet.prototype._nIndex = null;

/**
 * Internal counter of how many records are in the RecordSet
 *
 * @property _length
 * @private
 */
YAHOO.widget.RecordSet.prototype._length = null;

/////////////////////////////////////////////////////////////////////////////
//
// Private methods
//
/////////////////////////////////////////////////////////////////////////////

/////////////////////////////////////////////////////////////////////////////
//
// Public methods
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Public accessor to the unique name of the RecordSet instance.
 *
 * @method toString
 * @return {string} Unique name of the RecordSet instance
 */
YAHOO.widget.RecordSet.prototype.toString = function() {
    return "RecordSet instance " + this._nIndex;
};

/**
 * Returns the number of non-null records in the sparse RecordSet
 *
 * @method getLength
 * @return {Number} Number records in the RecordSet
 */
YAHOO.widget.RecordSet.prototype.getLength = function() {
        return this._length;
};

/**
 * Returns record with given name, at the given index, or null.
 *
 * @method getRecord
 * @param identifier {String || Number} Record ID or record index
 * @return {Object} Record object
 */
YAHOO.widget.RecordSet.prototype.getRecord = function(identifier) {
    if(identifier) {
        if(identifier.constructor == String) {
            for(var i=0; i<this._records.length; i++) {
                if(this._records[i].id == identifier) {
                    return this._records[i];
                }
            }
            return null;
        }
        else {
            return this._records[identifier];
        }
    }
    return null;
};

/**
 * Returns an array of Records from the RecordSet.
 *
 * @method getRecords
 * @param i {number} Index of which record to start at
 * @param range {number} (optional) Number of records to get
 * @return {Array} Array of records starting at given index and lenth equal to
 * given range. If range is null, entire RecordSet array is returned.
 */
YAHOO.widget.RecordSet.prototype.getRecords = function(i, range) {
    if(i === undefined) {
        return this._records;
    }
    i = parseInt(i,10);
    if(isNaN(i)) {
        return null;
    }
    if(range === undefined) {
        return this._records.slice(i);
    }
    range = parseInt(range,10);
    if(isNaN(range)) {
        return null;
    }
    return this._records.slice(i, i+range);
};

/**
 * Returns index for the given record.
 *
 * @method getRecordIndex
 * @param oRecord {object} Record object
 * @return {number} index
 */

/*YAHOO.widget.RecordSet.prototype.getRecordIndex = function(oRecord) {
    //TODO: return i;
};*/

/**
 * Returns the record(2) with the given value at the given key.
 *
 * @method getRecordBy
 * @param sKey {String} Key to search.
 * @param oValue {Object} to match against.
 * @return {YAHOO.widget.Record || YAHOO.widget.Record[]} Record or array of
 * Records with the given value at the given key, or null.
 */
/*YAHOO.widget.RecordSet.prototype.getRecordBy = function(sKey, oValue) {
     TODO: redo to match new algorithm
    var record = null;
    var length = this._records.length;
    for(var i=length-1; i>0; i--) {
        record = this._records[i];
        if(record && (record.extid == extId)) {
            return record;
        }
    }
    return null;

};*/

/**
 * Updates given Record at given key with given data.
 *
 * @method updateRecord
 * @param oRecord {YAHOO.widget.Record} A Record instance.
 * @param sKey {String} Key.
 * @param oData {Object) New data.
 */
YAHOO.widget.RecordSet.prototype.updateRecord = function(oRecord, sKey, oData) {
    var oldData = oRecord[sKey];
    oRecord[sKey] = oData;
    this.fireEvent("recordUpdateEvent",{record:oRecord,key:sKey,newData:oData,oldData:oldData});
};

/**
 * Adds one Record to the RecordSet at the given index. If index is null,
 * then adds the Record to the end of the RecordSet.
 *
 * @method addRecord
 * @param oObjectLiteral {Object} An object literal of data.
 * @param index {Number} (optional) Position index.
 * @return {YAHOO.widget.Record} A Record instance.
 */
YAHOO.widget.RecordSet.prototype.addRecord = function(oObjectLiteral, index) {
    if(oObjectLiteral) {
        var oRecord = new YAHOO.widget.Record(oObjectLiteral);
        if(!isNaN(index) && (index > -1)) {
            this._records.splice(index,0,oRecord);
        }
        else {
            this._records.push(oRecord);
        }
        this._length++;
        return oRecord;
    }
    else {
        return null;
    }
};

/**
 * Adds multiple Records to the RecordSet at the given index. If index is null,
 * then adds the Records to the end of the RecordSet.
 *
 * @method addRecords
 * @param data {Object[]} An array of object literal data.
 * @param index {Number} (optional) Position index.
 * @return {YAHOO.widget.Record} An array of Record instances.
 */
YAHOO.widget.RecordSet.prototype.addRecords = function(data, index) {
    if(data) {
        if(data.constructor == Array) {
            var newRecords = [];
            // Can't go backwards bc we need to preserve order
            for(var i=0; i<data.length; i++) {
                var record = this.addRecord(data[i], index);
                newRecords.push(record);
           }
           return newRecords;
        }
        else if(data.constructor == Object) {
            return this.addRecord(data);
        }
    }
    else {
        return null;
    }
};

/**
 * Convenience method to append the given data to the end of the RecordSet.
 *
 * @method append
 * @param data {Object || Object[]} An object literal or array of data.
 * @return {YAHOO.widget.Record || YAHOO.widget.Record[]} A Record or array of Records.
 */
YAHOO.widget.RecordSet.prototype.append = function(data) {
    if(data) {
        if(data.constructor == Array) {
            var newRecords = [];
            // Cant't go backwards bc we need to preserve order
            for(var i=0; i<data.length; i++) {
                var record = this.addRecord(data[i]);
                newRecords.push(record);
           }
           return newRecords;
        }
        else if(data.constructor == Object) {
            return this.addRecord(data);
        }
    }
    else {
        return null;
    }
    
};

/**
 * Convenience method to insert the given data into the beginning of the RecordSet.
 *
 * @method insert
 * @param data {Object || Object[]} An object literal or array of data.
 * @return {YAHOO.widget.Record || YAHOO.widget.Record[]} A Record or array of Records.
 */
YAHOO.widget.RecordSet.prototype.insert = function(data) {
    if(data) {
        if(data.constructor == Array) {
            var newRecords = [];
            // Can't go backwards bc we need to preserve order
            for(var i=data.length-1; i>-1; i--) {
                var record = this.addRecord(data[i], 0);
                newRecords.push(record);
           }
           return newRecords;
        }
        else if(data.constructor == Object) {
            return this.addRecord(data, 0);
        }
    }
    else {
        return null;
    }
};

/**
 * Replaces all Records in RecordSet with new data.
 *
 * @method replace
 * @param data {Object || Object[]} An object literal or array or data.
 * @return {YAHOO.widget.Record || YAHOO.widget.Record[]} A Record or array of Records.
 */
YAHOO.widget.RecordSet.prototype.replace = function(data) {
    if(data) {
        this.reset();
        return this.append(data);
    }
    else {
        return null;
    }
};

/**
 * Sorts RecordSet by given function.
 *
 * @method sort
 * @param fnSort {Function} Reference to a sort function.
 * @return {Array} Sorted array of Records
 */
YAHOO.widget.RecordSet.prototype.sort = function(fnSort) {
    return this._records.sort(fnSort);
};


/**
 * Removes the record at the given index from the RecordSet. If a range is
 * given, starts at the given index and removes all records in the range.
 *
 * @method deleteRecord
 * @param i {Number} Record index
 * @param range {Number} (optional) Range of records to remove, or null.
 */
YAHOO.widget.RecordSet.prototype.deleteRecord = function(i, range) {
    if(!range || isNaN(range)) {
        range = 1;
    }
    if(i && !isNaN(i)) {
        this._records.splice(i, range);
        this._length = this._length - range;
    }
};

/**
 * Removes all Records from the RecordSet.
 *
 * @method reset
 */
YAHOO.widget.RecordSet.prototype.reset = function() {
    this._records = [];
    this._length = 0;
};


/****************************************************************************/
/****************************************************************************/
/****************************************************************************/

/**
 * The Record class defines a DataTable record.
 *
 * @class Record
 * @constructor
 * @param oConfigs {Object} (optional) Object literal of key/value pairs.
 */
YAHOO.widget.Record = function(oLiteral) {
    if(typeof oLiteral == "object") {
        for(var sKey in oLiteral) {
            if(sKey) {
                this[sKey] = oLiteral[sKey];
            }
        }
    }
    this.id = "yui-dtrec"+YAHOO.widget.Record._nCount;
    YAHOO.widget.Record._nCount++;
};

/////////////////////////////////////////////////////////////////////////////
//
// Private member variables
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Internal class variable to index multiple data table instances.
 *
 * @property _nCount
 * @type number
 * @private
 * @static
 */
YAHOO.widget.Record._nCount = 0;

/////////////////////////////////////////////////////////////////////////////
//
// Public member variables
//
/////////////////////////////////////////////////////////////////////////////

/**
 * Unique name assigned at instantation, indicates original order.
 *
 * @property id
 * @type string
 */
YAHOO.widget.Record.prototype.id = null;

YAHOO.register("datatable", YAHOO.widget.DataTable, {version: "2.2.0", build: "122"});