1 files changed, 2258 insertions, 2258 deletions
diff --git a/framework/Web/UI/WebControls/TDataGrid.php b/framework/Web/UI/WebControls/TDataGrid.php
index 2af66b33..2e2c5252 100644
--- a/framework/Web/UI/WebControls/TDataGrid.php
+++ b/framework/Web/UI/WebControls/TDataGrid.php
@@ -1,2258 +1,2258 @@
-<?php
-/**
- * TDataGrid related class files.
- * This file contains the definition of the following classes:
- * TDataGrid, TDataGridItem, TDataGridItemCollection, TDataGridColumnCollection,
- * TDataGridPagerStyle, TDataGridItemEventParameter,
- * TDataGridCommandEventParameter, TDataGridSortCommandEventParameter,
- * TDataGridPageChangedEventParameter
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @link http://www.pradosoft.com/
- * @copyright Copyright &copy; 2005-2012 PradoSoft
- * @license http://www.pradosoft.com/license/
- * @version $Id$
- * @package System.Web.UI.WebControls
- */
-
-/**
- * Includes TBaseList, TPagedDataSource, TDummyDataSource and TTable classes
- */
-Prado::using('System.Web.UI.WebControls.TBaseDataList');
-Prado::using('System.Collections.TPagedDataSource');
-Prado::using('System.Collections.TDummyDataSource');
-Prado::using('System.Web.UI.WebControls.TTable');
-Prado::using('System.Web.UI.WebControls.TPanel');
-Prado::using('System.Web.UI.WebControls.TDataGridPagerStyle');
-
-/**
- * TDataGrid class
- *
- * TDataGrid represents a data bound and updatable grid control.
- *
- * To populate data into the datagrid, sets its {@link setDataSource DataSource}
- * to a tabular data source and call {@link dataBind()}.
- * Each row of data will be represented by an item in the {@link getItems Items}
- * collection of the datagrid.
- *
- * An item can be at one of three states: browsing, selected and edit.
- * The state determines how the item will be displayed. For example, if an item
- * is in edit state, it may be displayed as a table row with input text boxes
- * if the columns are of type {@link TBoundColumn}; and if in browsing state,
- * they are displayed as static text.
- *
- * To change the state of an item, set {@link setEditItemIndex EditItemIndex}
- * or {@link setSelectedItemIndex SelectedItemIndex} property.
- *
- * Each datagrid item has a {@link TDataGridItem::getItemType type}
- * which tells the position and state of the item in the datalist. An item in the header
- * of the repeater is of type Header. A body item may be of either
- * Item, AlternatingItem, SelectedItem or EditItem, depending whether the item
- * index is odd or even, whether it is being selected or edited.
- *
- * A datagrid is specified with a list of columns. Each column specifies how the corresponding
- * table column will be displayed. For example, the header/footer text of that column,
- * the cells in that column, and so on. The following column types are currently
- * provided by the framework,
- * - {@link TBoundColumn}, associated with a specific field in datasource and displays the corresponding data.
- * - {@link TEditCommandColumn}, displaying edit/update/cancel command buttons
- * - {@link TButtonColumn}, displaying generic command buttons that may be bound to specific field in datasource.
- * - {@link TDropDownListColumn}, displaying a dropdown list when the item is in edit state
- * - {@link THyperLinkColumn}, displaying a hyperlink that may be bound to specific field in datasource.
- * - {@link TCheckBoxColumn}, displaying a checkbox that may be bound to specific field in datasource.
- * - {@link TTemplateColumn}, displaying content based on templates.
- *
- * There are three ways to specify columns for a datagrid.
- * <ul>
- *  <li>Automatically generated based on data source.
- *  By setting {@link setAutoGenerateColumns AutoGenerateColumns} to true,
- *  a list of columns will be automatically generated based on the schema of the data source.
- *  Each column corresponds to a column of the data.</li>
- *  <li>Specified in template. For example,
- *    <code>
- *     <com:TDataGrid ...>
- *        <com:TBoundColumn .../>
- *        <com:TEditCommandColumn .../>
- *     </com:TDataGrid>
- *    </code>
- *  </li>
- *  <li>Manually created in code. Columns can be manipulated via
- *  the {@link setColumns Columns} property of the datagrid. For example,
- *  <code>
- *    $column=new TBoundColumn;
- *    $datagrid->Columns[]=$column;
- *  </code>
- *  </li>
- * </ul>
- * Note, automatically generated columns cannot be accessed via
- * the {@link getColumns Columns} property.
- *
- * TDataGrid supports sorting. If the {@link setAllowSorting AllowSorting}
- * is set to true, a column with nonempty {@link setSortExpression SortExpression}
- * will have its header text displayed as a clickable link button.
- * Clicking on the link button will raise {@link onSortCommand OnSortCommand}
- * event. You can respond to this event, sort the data source according
- * to the event parameter, and then invoke {@link databind()} on the datagrid
- * to show to end users the sorted data.
- *
- * TDataGrid supports paging. If the {@link setAllowPaging AllowPaging}
- * is set to true, a pager will be displayed on top and/or bottom of the table.
- * How the pager will be displayed is determined by the {@link getPagerStyle PagerStyle}
- * property. Clicking on a pager button will raise an {@link onPageIndexChanged OnPageIndexChanged}
- * event. You can respond to this event, specify the page to be displayed by
- * setting {@link setCurrentPageIndex CurrentPageIndex}</b> property,
- * and then invoke {@link databind()} on the datagrid to show to end users
- * a new page of data.
- *
- * TDataGrid supports two kinds of paging. The first one is based on the number of data items in
- * datasource. The number of pages {@link getPageCount PageCount} is calculated based
- * the item number and the {@link setPageSize PageSize} property.
- * The datagrid will manage which section of the data source to be displayed
- * based on the {@link setCurrentPageIndex CurrentPageIndex} property.
- * The second approach calculates the page number based on the
- * {@link setVirtualItemCount VirtualItemCount} property and
- * the {@link setPageSize PageSize} property. The datagrid will always
- * display from the beginning of the datasource up to the number of
- * {@link setPageSize PageSize} data items. This approach is especially
- * useful when the datasource may contain too many data items to be managed by
- * the datagrid efficiently.
- *
- * When the datagrid contains a button control that raises an {@link onCommand OnCommand}
- * event, the event will be bubbled up to the datagrid control.
- * If the event's command name is recognizable by the datagrid control,
- * a corresponding item event will be raised. The following item events will be
- * raised upon a specific command:
- * - OnEditCommand, if CommandName=edit
- * - OnCancelCommand, if CommandName=cancel
- * - OnSelectCommand, if CommandName=select
- * - OnDeleteCommand, if CommandName=delete
- * - OnUpdateCommand, if CommandName=update
- * - onPageIndexChanged, if CommandName=page
- * - OnSortCommand, if CommandName=sort
- * Note, an {@link onItemCommand OnItemCommand} event is raised in addition to
- * the above specific command events.
- *
- * TDataGrid also raises an {@link onItemCreated OnItemCreated} event for
- * every newly created datagrid item. You can respond to this event to customize
- * the content or style of the newly created item.
- *
- * Note, the data bound to the datagrid are reset to null after databinding.
- * There are several ways to access the data associated with a datagrid row:
- * - Access the data in {@link onItemDataBound OnItemDataBound} event
- * - Use {@link getDataKeys DataKeys} to obtain the data key associated with
- * the specified datagrid row and use the key to fetch the corresponding data
- * from some persistent storage such as DB.
- * - Save the data in viewstate and get it back during postbacks.
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id$
- * @package System.Web.UI.WebControls
- * @since 3.0
- */
-class TDataGrid extends TBaseDataList implements INamingContainer
-{
-	/**
-	 * datagrid item types
-	 * @deprecated deprecated since version 3.0.4. Use TListItemType constants instead.
-	 */
-	const IT_HEADER='Header';
-	const IT_FOOTER='Footer';
-	const IT_ITEM='Item';
-	const IT_SEPARATOR='Separator';
-	const IT_ALTERNATINGITEM='AlternatingItem';
-	const IT_EDITITEM='EditItem';
-	const IT_SELECTEDITEM='SelectedItem';
-	const IT_PAGER='Pager';
-
-	/**
-	 * Command name that TDataGrid understands.
-	 */
-	const CMD_SELECT='Select';
-	const CMD_EDIT='Edit';
-	const CMD_UPDATE='Update';
-	const CMD_DELETE='Delete';
-	const CMD_CANCEL='Cancel';
-	const CMD_SORT='Sort';
-	const CMD_PAGE='Page';
-	const CMD_PAGE_NEXT='Next';
-	const CMD_PAGE_PREV='Previous';
-	const CMD_PAGE_FIRST='First';
-	const CMD_PAGE_LAST='Last';
-
-	/**
-	 * @var TDataGridColumnCollection manually created column collection
-	 */
-	private $_columns=null;
-	/**
-	 * @var TDataGridColumnCollection automatically created column collection
-	 */
-	private $_autoColumns=null;
-	/**
-	 * @var TList all columns including both manually and automatically created columns
-	 */
-	private $_allColumns=null;
-	/**
-	 * @var TDataGridItemCollection datagrid item collection
-	 */
-	private $_items=null;
-	/**
-	 * @var TDataGridItem header item
-	 */
-	private $_header=null;
-	/**
-	 * @var TDataGridItem footer item
-	 */
-	private $_footer=null;
-	/**
-	 * @var TPagedDataSource paged data source object
-	 */
-	private $_pagedDataSource=null;
-	private $_topPager=null;
-	private $_bottomPager=null;
-	/**
-	 * @var ITemplate template used when empty data is bounded
-	 */
-	private $_emptyTemplate=null;
-	/**
-	 * @var boolean whether empty template is effective
-	 */
-	private $_useEmptyTemplate=false;
-
-	/**
-	 * @return string tag name (table) of the datagrid
-	 */
-	protected function getTagName()
-	{
-		return 'table';
-	}
-
-	/**
-	 * @return string Name of the class used in AutoGenerateColumns mode
-	 */
-	protected function getAutoGenerateColumnName()
-	{
-		return 'TBoundColumn';
-	}
-
-	/**
-	 * Adds objects parsed in template to datagrid.
-	 * Datagrid columns are added into {@link getColumns Columns} collection.
-	 * @param mixed object parsed in template
-	 */
-	public function addParsedObject($object)
-	{
-		if($object instanceof TDataGridColumn)
-			$this->getColumns()->add($object);
-		else
-			parent::addParsedObject($object);  // this is needed by EmptyTemplate
-	}
-
-	/**
-	 * @return TDataGridColumnCollection manually specified datagrid columns
-	 */
-	public function getColumns()
-	{
-		if(!$this->_columns)
-			$this->_columns=new TDataGridColumnCollection($this);
-		return $this->_columns;
-	}
-
-	/**
-	 * @return TDataGridColumnCollection automatically generated datagrid columns
-	 */
-	public function getAutoColumns()
-	{
-		if(!$this->_autoColumns)
-			$this->_autoColumns=new TDataGridColumnCollection($this);
-		return $this->_autoColumns;
-	}
-
-	/**
-	 * @return TDataGridItemCollection datagrid item collection
-	 */
-	public function getItems()
-	{
-		if(!$this->_items)
-			$this->_items=new TDataGridItemCollection;
-		return $this->_items;
-	}
-
-	/**
-	 * @return integer number of items
-	 */
-	public function getItemCount()
-	{
-		return $this->_items?$this->_items->getCount():0;
-	}
-
-	/**
-	 * Creates a style object for the control.
-	 * This method creates a {@link TTableStyle} to be used by datagrid.
-	 * @return TTableStyle control style to be used
-	 */
-	protected function createStyle()
-	{
-		return new TTableStyle;
-	}
-
-	/**
-	 * @return string the URL of the background image for the datagrid
-	 */
-	public function getBackImageUrl()
-	{
-		return $this->getStyle()->getBackImageUrl();
-	}
-
-	/**
-	 * @param string the URL of the background image for the datagrid
-	 */
-	public function setBackImageUrl($value)
-	{
-		$this->getStyle()->setBackImageUrl($value);
-	}
-
-	/**
-	 * @return TTableItemStyle the style for every item
-	 */
-	public function getItemStyle()
-	{
-		if(($style=$this->getViewState('ItemStyle',null))===null)
-		{
-			$style=new TTableItemStyle;
-			$this->setViewState('ItemStyle',$style,null);
-		}
-		return $style;
-	}
-
-	/**
-	 * @return TTableItemStyle the style for each alternating item
-	 */
-	public function getAlternatingItemStyle()
-	{
-		if(($style=$this->getViewState('AlternatingItemStyle',null))===null)
-		{
-			$style=new TTableItemStyle;
-			$this->setViewState('AlternatingItemStyle',$style,null);
-		}
-		return $style;
-	}
-
-	/**
-	 * @return TTableItemStyle the style for selected item
-	 */
-	public function getSelectedItemStyle()
-	{
-		if(($style=$this->getViewState('SelectedItemStyle',null))===null)
-		{
-			$style=new TTableItemStyle;
-			$this->setViewState('SelectedItemStyle',$style,null);
-		}
-		return $style;
-	}
-
-	/**
-	 * @return TTableItemStyle the style for edit item
-	 */
-	public function getEditItemStyle()
-	{
-		if(($style=$this->getViewState('EditItemStyle',null))===null)
-		{
-			$style=new TTableItemStyle;
-			$this->setViewState('EditItemStyle',$style,null);
-		}
-		return $style;
-	}
-
-	/**
-	 * @return TTableItemStyle the style for header
-	 */
-	public function getHeaderStyle()
-	{
-		if(($style=$this->getViewState('HeaderStyle',null))===null)
-		{
-			$style=new TTableItemStyle;
-			$this->setViewState('HeaderStyle',$style,null);
-		}
-		return $style;
-	}
-
-	/**
-	 * @return TTableItemStyle the style for footer
-	 */
-	public function getFooterStyle()
-	{
-		if(($style=$this->getViewState('FooterStyle',null))===null)
-		{
-			$style=new TTableItemStyle;
-			$this->setViewState('FooterStyle',$style,null);
-		}
-		return $style;
-	}
-
-	/**
-	 * @return TDataGridPagerStyle the style for pager
-	 */
-	public function getPagerStyle()
-	{
-		if(($style=$this->getViewState('PagerStyle',null))===null)
-		{
-			$style=new TDataGridPagerStyle;
-			$this->setViewState('PagerStyle',$style,null);
-		}
-		return $style;
-	}
-
-	/**
-	 * @return TStyle the style for thead element, if any
-	 * @since 3.1.1
-	 */
-	public function getTableHeadStyle()
-	{
-		if(($style=$this->getViewState('TableHeadStyle',null))===null)
-		{
-			$style=new TStyle;
-			$this->setViewState('TableHeadStyle',$style,null);
-		}
-		return $style;
-	}
-
-	/**
-	 * @return TStyle the style for tbody element, if any
-	 * @since 3.1.1
-	 */
-	public function getTableBodyStyle()
-	{
-		if(($style=$this->getViewState('TableBodyStyle',null))===null)
-		{
-			$style=new TStyle;
-			$this->setViewState('TableBodyStyle',$style,null);
-		}
-		return $style;
-	}
-
-	/**
-	 * @return TStyle the style for tfoot element, if any
-	 * @since 3.1.1
-	 */
-	public function getTableFootStyle()
-	{
-		if(($style=$this->getViewState('TableFootStyle',null))===null)
-		{
-			$style=new TStyle;
-			$this->setViewState('TableFootStyle',$style,null);
-		}
-		return $style;
-	}
-
-	/**
-	 * @return string caption for the datagrid
-	 */
-	public function getCaption()
-	{
-		return $this->getViewState('Caption','');
-	}
-
-	/**
-	 * @param string caption for the datagrid
-	 */
-	public function setCaption($value)
-	{
-		$this->setViewState('Caption',$value,'');
-	}
-
-	/**
-	 * @return TTableCaptionAlign datagrid caption alignment. Defaults to TTableCaptionAlign::NotSet.
-	 */
-	public function getCaptionAlign()
-	{
-		return $this->getViewState('CaptionAlign',TTableCaptionAlign::NotSet);
-	}
-
-	/**
-	 * @param TTableCaptionAlign datagrid caption alignment. Valid values include
-	 */
-	public function setCaptionAlign($value)
-	{
-		$this->setViewState('CaptionAlign',TPropertyValue::ensureEnum($value,'TTableCaptionAlign'),TTableCaptionAlign::NotSet);
-	}
-
-	/**
-	 * @return TDataGridItem the header item
-	 */
-	public function getHeader()
-	{
-		return $this->_header;
-	}
-
-	/**
-	 * @return TDataGridItem the footer item
-	 */
-	public function getFooter()
-	{
-		return $this->_footer;
-	}
-
-	/**
-	 * @return TDataGridPager the pager displayed at the top of datagrid. It could be null if paging is disabled.
-	 */
-	public function getTopPager()
-	{
-		return $this->_topPager;
-	}
-
-	/**
-	 * @return TDataGridPager the pager displayed at the bottom of datagrid. It could be null if paging is disabled.
-	 */
-	public function getBottomPager()
-	{
-		return $this->_bottomPager;
-	}
-
-	/**
-	 * @return TDataGridItem the selected item, null if no item is selected.
-	 */
-	public function getSelectedItem()
-	{
-		$index=$this->getSelectedItemIndex();
-		$items=$this->getItems();
-		if($index>=0 && $index<$items->getCount())
-			return $items->itemAt($index);
-		else
-			return null;
-	}
-
-	/**
-	 * @return integer the zero-based index of the selected item in {@link getItems Items}.
-	 * A value -1 means no item selected.
-	 */
-	public function getSelectedItemIndex()
-	{
-		return $this->getViewState('SelectedItemIndex',-1);
-	}
-
-	/**
-	 * Selects an item by its index in {@link getItems Items}.
-	 * Previously selected item will be un-selected.
-	 * If the item to be selected is already in edit mode, it will remain in edit mode.
-	 * If the index is less than 0, any existing selection will be cleared up.
-	 * @param integer the selected item index
-	 */
-	public function setSelectedItemIndex($value)
-	{
-		if(($value=TPropertyValue::ensureInteger($value))<0)
-			$value=-1;
-		if(($current=$this->getSelectedItemIndex())!==$value)
-		{
-			$this->setViewState('SelectedItemIndex',$value,-1);
-			$items=$this->getItems();
-			$itemCount=$items->getCount();
-			if($current>=0 && $current<$itemCount)
-			{
-				$item=$items->itemAt($current);
-				if($item->getItemType()!==TListItemType::EditItem)
-					$item->setItemType($current%2?TListItemType::AlternatingItem:TListItemType::Item);
-			}
-			if($value>=0 && $value<$itemCount)
-			{
-				$item=$items->itemAt($value);
-				if($item->getItemType()!==TListItemType::EditItem)
-					$item->setItemType(TListItemType::SelectedItem);
-			}
-		}
-	}
-
-	/**
-	 * @return TDataGridItem the edit item
-	 */
-	public function getEditItem()
-	{
-		$index=$this->getEditItemIndex();
-		$items=$this->getItems();
-		if($index>=0 && $index<$items->getCount())
-			return $items->itemAt($index);
-		else
-			return null;
-	}
-
-	/**
-	 * @return integer the zero-based index of the edit item in {@link getItems Items}.
-	 * A value -1 means no item is in edit mode.
-	 */
-	public function getEditItemIndex()
-	{
-		return $this->getViewState('EditItemIndex',-1);
-	}
-
-	/**
-	 * Edits an item by its index in {@link getItems Items}.
-	 * Previously editting item will change to normal item state.
-	 * If the index is less than 0, any existing edit item will be cleared up.
-	 * @param integer the edit item index
-	 */
-	public function setEditItemIndex($value)
-	{
-		if(($value=TPropertyValue::ensureInteger($value))<0)
-			$value=-1;
-		if(($current=$this->getEditItemIndex())!==$value)
-		{
-			$this->setViewState('EditItemIndex',$value,-1);
-			$items=$this->getItems();
-			$itemCount=$items->getCount();
-			if($current>=0 && $current<$itemCount)
-				$items->itemAt($current)->setItemType($current%2?TListItemType::AlternatingItem:TListItemType::Item);
-			if($value>=0 && $value<$itemCount)
-				$items->itemAt($value)->setItemType(TListItemType::EditItem);
-		}
-	}
-
-	/**
-	 * @return boolean whether sorting is enabled. Defaults to false.
-	 */
-	public function getAllowSorting()
-	{
-		return $this->getViewState('AllowSorting',false);
-	}
-
-	/**
-	 * @param boolean whether sorting is enabled
-	 */
-	public function setAllowSorting($value)
-	{
-		$this->setViewState('AllowSorting',TPropertyValue::ensureBoolean($value),false);
-	}
-
-	/**
-	 * @return boolean whether datagrid columns should be automatically generated. Defaults to true.
-	 */
-	public function getAutoGenerateColumns()
-	{
-		return $this->getViewState('AutoGenerateColumns',true);
-	}
-
-	/**
-	 * @param boolean whether datagrid columns should be automatically generated
-	 */
-	public function setAutoGenerateColumns($value)
-	{
-		$this->setViewState('AutoGenerateColumns',TPropertyValue::ensureBoolean($value),true);
-	}
-
-	/**
-	 * @return boolean whether the header should be displayed. Defaults to true.
-	 */
-	public function getShowHeader()
-	{
-		return $this->getViewState('ShowHeader',true);
-	}
-
-	/**
-	 * @param boolean whether the header should be displayed
-	 */
-	public function setShowHeader($value)
-	{
-		$this->setViewState('ShowHeader',TPropertyValue::ensureBoolean($value),true);
-	}
-
-	/**
-	 * @return boolean whether the footer should be displayed. Defaults to false.
-	 */
-	public function getShowFooter()
-	{
-		return $this->getViewState('ShowFooter',false);
-	}
-
-	/**
-	 * @param boolean whether the footer should be displayed
-	 */
-	public function setShowFooter($value)
-	{
-		$this->setViewState('ShowFooter',TPropertyValue::ensureBoolean($value),false);
-	}
-
-	/**
-	 * @return ITemplate the template applied when no data is bound to the datagrid
-	 */
-	public function getEmptyTemplate()
-	{
-		return $this->_emptyTemplate;
-	}
-
-	/**
-	 * @param ITemplate the template applied when no data is bound to the datagrid
-	 * @throws TInvalidDataTypeException if the input is not an {@link ITemplate} or not null.
-	 */
-	public function setEmptyTemplate($value)
-	{
-		if($value instanceof ITemplate || $value===null)
-			$this->_emptyTemplate=$value;
-		else
-			throw new TInvalidDataTypeException('datagrid_template_required','EmptyTemplate');
-	}
-
-	/**
-	 * This method overrides parent's implementation to handle
-	 * {@link onItemCommand OnItemCommand} event which is bubbled from
-	 * {@link TDataGridItem} child controls.
-	 * If the event parameter is {@link TDataGridCommandEventParameter} and
-	 * the command name is a recognized one, which includes 'select', 'edit',
-	 * 'delete', 'update', and 'cancel' (case-insensitive), then a
-	 * corresponding command event is also raised (such as {@link onEditCommand OnEditCommand}).
-	 * This method should only be used by control developers.
-	 * @param TControl the sender of the event
-	 * @param TEventParameter event parameter
-	 * @return boolean whether the event bubbling should stop here.
-	 */
-	public function bubbleEvent($sender,$param)
-	{
-		if($param instanceof TDataGridCommandEventParameter)
-		{
-			$this->onItemCommand($param);
-			$command=$param->getCommandName();
-			if(strcasecmp($command,self::CMD_SELECT)===0)
-			{
-				$this->setSelectedItemIndex($param->getItem()->getItemIndex());
-				$this->onSelectedIndexChanged($param);
-				return true;
-			}
-			else if(strcasecmp($command,self::CMD_EDIT)===0)
-			{
-				$this->onEditCommand($param);
-				return true;
-			}
-			else if(strcasecmp($command,self::CMD_DELETE)===0)
-			{
-				$this->onDeleteCommand($param);
-				return true;
-			}
-			else if(strcasecmp($command,self::CMD_UPDATE)===0)
-			{
-				$this->onUpdateCommand($param);
-				return true;
-			}
-			else if(strcasecmp($command,self::CMD_CANCEL)===0)
-			{
-				$this->onCancelCommand($param);
-				return true;
-			}
-			else if(strcasecmp($command,self::CMD_SORT)===0)
-			{
-				$this->onSortCommand(new TDataGridSortCommandEventParameter($sender,$param));
-				return true;
-			}
-			else if(strcasecmp($command,self::CMD_PAGE)===0)
-			{
-				$p=$param->getCommandParameter();
-				if(strcasecmp($p,self::CMD_PAGE_NEXT)===0)
-					$pageIndex=$this->getCurrentPageIndex()+1;
-				else if(strcasecmp($p,self::CMD_PAGE_PREV)===0)
-					$pageIndex=$this->getCurrentPageIndex()-1;
-				else if(strcasecmp($p,self::CMD_PAGE_FIRST)===0)
-					$pageIndex=0;
-				else if(strcasecmp($p,self::CMD_PAGE_LAST)===0)
-					$pageIndex=$this->getPageCount()-1;
-				else
-					$pageIndex=TPropertyValue::ensureInteger($p)-1;
-				$this->onPageIndexChanged(new TDataGridPageChangedEventParameter($sender,$pageIndex));
-				return true;
-			}
-		}
-		return false;
-	}
-
-	/**
-	 * Raises <b>OnCancelCommand</b> event.
-	 * This method is invoked when a button control raises <b>OnCommand</b> event
-	 * with <b>cancel</b> command name.
-	 * @param TDataGridCommandEventParameter event parameter
-	 */
-	public function onCancelCommand($param)
-	{
-		$this->raiseEvent('OnCancelCommand',$this,$param);
-	}
-
-	/**
-	 * Raises <b>OnDeleteCommand</b> event.
-	 * This method is invoked when a button control raises <b>OnCommand</b> event
-	 * with <b>delete</b> command name.
-	 * @param TDataGridCommandEventParameter event parameter
-	 */
-	public function onDeleteCommand($param)
-	{
-		$this->raiseEvent('OnDeleteCommand',$this,$param);
-	}
-
-	/**
-	 * Raises <b>OnEditCommand</b> event.
-	 * This method is invoked when a button control raises <b>OnCommand</b> event
-	 * with <b>edit</b> command name.
-	 * @param TDataGridCommandEventParameter event parameter
-	 */
-	public function onEditCommand($param)
-	{
-		$this->raiseEvent('OnEditCommand',$this,$param);
-	}
-
-	/**
-	 * Raises <b>OnItemCommand</b> event.
-	 * This method is invoked when a button control raises <b>OnCommand</b> event.
-	 * @param TDataGridCommandEventParameter event parameter
-	 */
-	public function onItemCommand($param)
-	{
-		$this->raiseEvent('OnItemCommand',$this,$param);
-	}
-
-	/**
-	 * Raises <b>OnSortCommand</b> event.
-	 * This method is invoked when a button control raises <b>OnCommand</b> event
-	 * with <b>sort</b> command name.
-	 * @param TDataGridSortCommandEventParameter event parameter
-	 */
-	public function onSortCommand($param)
-	{
-		$this->raiseEvent('OnSortCommand',$this,$param);
-	}
-
-	/**
-	 * Raises <b>OnUpdateCommand</b> event.
-	 * This method is invoked when a button control raises <b>OnCommand</b> event
-	 * with <b>update</b> command name.
-	 * @param TDataGridCommandEventParameter event parameter
-	 */
-	public function onUpdateCommand($param)
-	{
-		$this->raiseEvent('OnUpdateCommand',$this,$param);
-	}
-
-	/**
-	 * Raises <b>OnItemCreated</b> event.
-	 * This method is invoked right after a datagrid item is created and before
-	 * added to page hierarchy.
-	 * @param TDataGridItemEventParameter event parameter
-	 */
-	public function onItemCreated($param)
-	{
-		$this->raiseEvent('OnItemCreated',$this,$param);
-	}
-
-	/**
-	 * Raises <b>OnPagerCreated</b> event.
-	 * This method is invoked right after a datagrid pager is created and before
-	 * added to page hierarchy.
-	 * @param TDataGridPagerEventParameter event parameter
-	 */
-	public function onPagerCreated($param)
-	{
-		$this->raiseEvent('OnPagerCreated',$this,$param);
-	}
-
-	/**
-	 * Raises <b>OnItemDataBound</b> event.
-	 * This method is invoked for each datagrid item after it performs
-	 * databinding.
-	 * @param TDataGridItemEventParameter event parameter
-	 */
-	public function onItemDataBound($param)
-	{
-		$this->raiseEvent('OnItemDataBound',$this,$param);
-	}
-
-	/**
-	 * Raises <b>OnPageIndexChanged</b> event.
-	 * This method is invoked when current page is changed.
-	 * @param TDataGridPageChangedEventParameter event parameter
-	 */
-	public function onPageIndexChanged($param)
-	{
-		$this->raiseEvent('OnPageIndexChanged',$this,$param);
-	}
-
-	/**
-	 * Saves item count in viewstate.
-	 * This method is invoked right before control state is to be saved.
-	 */
-	public function saveState()
-	{
-		parent::saveState();
-		if(!$this->getEnableViewState(true))
-			return;
-		if($this->_items)
-			$this->setViewState('ItemCount',$this->_items->getCount(),0);
-		else
-			$this->clearViewState('ItemCount');
-		if($this->_autoColumns)
-		{
-			$state=array();
-			foreach($this->_autoColumns as $column)
-				$state[]=$column->saveState();
-			$this->setViewState('AutoColumns',$state,array());
-		}
-		else
-			$this->clearViewState('AutoColumns');
-		if($this->_columns)
-		{
-			$state=array();
-			foreach($this->_columns as $column)
-				$state[]=$column->saveState();
-			$this->setViewState('Columns',$state,array());
-		}
-		else
-			$this->clearViewState('Columns');
-	}
-
-	/**
-	 * Loads item count information from viewstate.
-	 * This method is invoked right after control state is loaded.
-	 */
-	public function loadState()
-	{
-		parent::loadState();
-		if(!$this->getEnableViewState(true))
-			return;
-		if(!$this->getIsDataBound())
-		{
-			$state=$this->getViewState('AutoColumns',array());
-			if(!empty($state))
-			{
-				$this->_autoColumns=new TDataGridColumnCollection($this);
-				foreach($state as $st)
-				{
-					$column=new $this->AutoGenerateColumnName;
-					$column->loadState($st);
-					$this->_autoColumns->add($column);
-				}
-			}
-			else
-				$this->_autoColumns=null;
-			$state=$this->getViewState('Columns',array());
-			if($this->_columns && $this->_columns->getCount()===count($state))
-			{
-				$i=0;
-				foreach($this->_columns as $column)
-				{
-					$column->loadState($state[$i]);
-					$i++;
-				}
-			}
-			$this->restoreGridFromViewState();
-		}
-	}
-
-	/**
-	 * Clears up all items in the datagrid.
-	 */
-	public function reset()
-	{
-		$this->getControls()->clear();
-		$this->getItems()->clear();
-		$this->_header=null;
-		$this->_footer=null;
-		$this->_topPager=null;
-		$this->_bottomPager=null;
-		$this->_useEmptyTemplate=false;
-	}
-
-	/**
-	 * Restores datagrid content from viewstate.
-	 */
-	protected function restoreGridFromViewState()
-	{
-		$this->reset();
-
-		$allowPaging=$this->getAllowPaging();
-
-		$itemCount=$this->getViewState('ItemCount',0);
-		$dsIndex=$this->getViewState('DataSourceIndex',0);
-
-		$columns=new TList($this->getColumns());
-		$columns->mergeWith($this->_autoColumns);
-		$this->_allColumns=$columns;
-
-		$items=$this->getItems();
-
-		if($columns->getCount())
-		{
-			foreach($columns as $column)
-				$column->initialize();
-			$selectedIndex=$this->getSelectedItemIndex();
-			$editIndex=$this->getEditItemIndex();
-			for($index=0;$index<$itemCount;++$index)
-			{
-				if($index===0)
-				{
-					if($allowPaging)
-						$this->_topPager=$this->createPager();
-					$this->_header=$this->createItemInternal(-1,-1,TListItemType::Header,false,null,$columns);
-				}
-				if($index===$editIndex)
-					$itemType=TListItemType::EditItem;
-				else if($index===$selectedIndex)
-					$itemType=TListItemType::SelectedItem;
-				else if($index % 2)
-					$itemType=TListItemType::AlternatingItem;
-				else
-					$itemType=TListItemType::Item;
-				$items->add($this->createItemInternal($index,$dsIndex,$itemType,false,null,$columns));
-				$dsIndex++;
-			}
-			if($index>0)
-			{
-				$this->_footer=$this->createItemInternal(-1,-1,TListItemType::Footer,false,null,$columns);
-				if($allowPaging)
-					$this->_bottomPager=$this->createPager();
-			}
-		}
-		if(!$dsIndex && $this->_emptyTemplate!==null)
-		{
-			$this->_useEmptyTemplate=true;
-			$this->_emptyTemplate->instantiateIn($this);
-		}
-	}
-
-	/**
-	 * Performs databinding to populate datagrid items from data source.
-	 * This method is invoked by {@link dataBind()}.
-	 * You may override this function to provide your own way of data population.
-	 * @param Traversable the bound data
-	 */
-	protected function performDataBinding($data)
-	{
-		$this->reset();
-		$keys=$this->getDataKeys();
-		$keys->clear();
-		$keyField=$this->getDataKeyField();
-
-		// get all columns
-		if($this->getAutoGenerateColumns())
-		{
-			$columns=new TList($this->getColumns());
-			$autoColumns=$this->createAutoColumns($data);
-			$columns->mergeWith($autoColumns);
-		}
-		else
-			$columns=$this->getColumns();
-		$this->_allColumns=$columns;
-
-		$items=$this->getItems();
-
-		$index=0;
-		$allowPaging=$this->getAllowPaging() && ($data instanceof TPagedDataSource);
-		$dsIndex=$allowPaging?$data->getFirstIndexInPage():0;
-		$this->setViewState('DataSourceIndex',$dsIndex,0);
-		if($columns->getCount())
-		{
-			foreach($columns as $column)
-				$column->initialize();
-
-			$selectedIndex=$this->getSelectedItemIndex();
-			$editIndex=$this->getEditItemIndex();
-			foreach($data as $key=>$row)
-			{
-				if($keyField!=='')
-					$keys->add($this->getDataFieldValue($row,$keyField));
-				else
-					$keys->add($key);
-				if($index===0)
-				{
-					if($allowPaging)
-						$this->_topPager=$this->createPager();
-					$this->_header=$this->createItemInternal(-1,-1,TListItemType::Header,true,null,$columns);
-				}
-				if($index===$editIndex)
-					$itemType=TListItemType::EditItem;
-				else if($index===$selectedIndex)
-					$itemType=TListItemType::SelectedItem;
-				else if($index % 2)
-					$itemType=TListItemType::AlternatingItem;
-				else
-					$itemType=TListItemType::Item;
-				$items->add($this->createItemInternal($index,$dsIndex,$itemType,true,$row,$columns));
-				$index++;
-				$dsIndex++;
-			}
-			if($index>0)
-			{
-				$this->_footer=$this->createItemInternal(-1,-1,TListItemType::Footer,true,null,$columns);
-				if($allowPaging)
-					$this->_bottomPager=$this->createPager();
-			}
-		}
-		$this->setViewState('ItemCount',$index,0);
-		if(!$dsIndex && $this->_emptyTemplate!==null)
-		{
-			$this->_useEmptyTemplate=true;
-			$this->_emptyTemplate->instantiateIn($this);
-			$this->dataBindChildren();
-		}
-	}
-
-	/**
-	 * Merges consecutive cells who have the same text.
-	 * @since 3.1.1
-	 */
-	private function groupCells()
-	{
-		if(($columns=$this->_allColumns)===null)
-			return;
-		$items=$this->getItems();
-		foreach($columns as $id=>$column)
-		{
-			if(!$column->getEnableCellGrouping())
-				continue;
-			$prevCell=null;
-			$prevCellText=null;
-			foreach($items as $item)
-			{
-				$itemType=$item->getItemType();
-				$cell=$item->getCells()->itemAt($id);
-				if(!$cell->getVisible())
-					continue;
-				if($itemType===TListItemType::Item || $itemType===TListItemType::AlternatingItem || $itemType===TListItemType::SelectedItem)
-				{
-					if(($cellText=$this->getCellText($cell))==='')
-					{
-						$prevCell=null;
-						$prevCellText=null;
-						continue;
-					}
-					if($prevCell===null || $prevCellText!==$cellText)
-					{
-						$prevCell=$cell;
-						$prevCellText=$cellText;
-					}
-					else
-					{
-						if(($rowSpan=$prevCell->getRowSpan())===0)
-							$rowSpan=1;
-						$prevCell->setRowSpan($rowSpan+1);
-						$cell->setVisible(false);
-					}
-				}
-			}
-		}
-	}
-
-	private function getCellText($cell)
-	{
-		if(($data=$cell->getText())==='' && $cell->getHasControls())
-		{
-			$controls=$cell->getControls();
-			foreach($controls as $control)
-			{
-				if($control instanceof IDataRenderer)
-					return $control->getData();
-			}
-		}
-		return $data;
-	}
-
-	/**
-	 * Creates a datagrid item instance based on the item type and index.
-	 * @param integer zero-based item index
-	 * @param TListItemType item type
-	 * @return TDataGridItem created data list item
-	 */
-	protected function createItem($itemIndex,$dataSourceIndex,$itemType)
-	{
-		return new TDataGridItem($itemIndex,$dataSourceIndex,$itemType);
-	}
-
-	private function createItemInternal($itemIndex,$dataSourceIndex,$itemType,$dataBind,$dataItem,$columns)
-	{
-		$item=$this->createItem($itemIndex,$dataSourceIndex,$itemType);
-		$this->initializeItem($item,$columns);
-		$param=new TDataGridItemEventParameter($item);
-		if($dataBind)
-		{
-			$item->setDataItem($dataItem);
-			$this->onItemCreated($param);
-			$this->getControls()->add($item);
-			$item->dataBind();
-			$this->onItemDataBound($param);
-		}
-		else
-		{
-			$this->onItemCreated($param);
-			$this->getControls()->add($item);
-		}
-		return $item;
-	}
-
-	/**
-	 * Initializes a datagrid item and cells inside it
-	 * @param TDataGrid datagrid item to be initialized
-	 * @param TDataGridColumnCollection datagrid columns to be used to initialize the cells in the item
-	 */
-	protected function initializeItem($item,$columns)
-	{
-		$cells=$item->getCells();
-		$itemType=$item->getItemType();
-		$index=0;
-		foreach($columns as $column)
-		{
-			if($itemType===TListItemType::Header)
-				$cell=new TTableHeaderCell;
-			else
-				$cell=new TTableCell;
-			if(($id=$column->getID())!=='')
-				$item->registerObject($id,$cell);
-			$cells->add($cell);
-			$column->initializeCell($cell,$index,$itemType);
-			$index++;
-		}
-	}
-
-	protected function createPager()
-	{
-		$pager=new TDataGridPager($this);
-		$this->buildPager($pager);
-		$this->onPagerCreated(new TDataGridPagerEventParameter($pager));
-		$this->getControls()->add($pager);
-		return $pager;
-	}
-
-	/**
-	 * Builds the pager content based on pager style.
-	 * @param TDataGridPager the container for the pager
-	 */
-	protected function buildPager($pager)
-	{
-		switch($this->getPagerStyle()->getMode())
-		{
-			case TDataGridPagerMode::NextPrev:
-				$this->buildNextPrevPager($pager);
-				break;
-			case TDataGridPagerMode::Numeric:
-				$this->buildNumericPager($pager);
-				break;
-		}
-	}
-
-	/**
-	 * Creates a pager button.
-	 * Depending on the button type, a TLinkButton or a TButton may be created.
-	 * If it is enabled (clickable), its command name and parameter will also be set.
-	 * Derived classes may override this method to create additional types of buttons, such as TImageButton.
-	 * @param mixed the container pager instance of TActiveDatagridPager 
-	 * @param string button type, either LinkButton or PushButton
-	 * @param boolean whether the button should be enabled
-	 * @param string caption of the button
-	 * @param string CommandName corresponding to the OnCommand event of the button
-	 * @param string CommandParameter corresponding to the OnCommand event of the button
-	 * @return mixed the button instance
-	 */
-	protected function createPagerButton($pager,$buttonType,$enabled,$text,$commandName,$commandParameter)
-	{
-		if($buttonType===TDataGridPagerButtonType::LinkButton)
-		{
-			if($enabled)
-				$button=new TLinkButton;
-			else
-			{
-				$button=new TLabel;
-				$button->setText($text);
-				return $button;
-			}
-		}
-		else
-		{
-			$button=new TButton;
-			if(!$enabled)
-				$button->setEnabled(false);
-		}
-		$button->setText($text);
-		$button->setCommandName($commandName);
-		$button->setCommandParameter($commandParameter);
-		$button->setCausesValidation(false);
-		return $button;
-	}
-
-	/**
-	 * Builds a next-prev pager
-	 * @param TDataGridPager the container for the pager
-	 */
-	protected function buildNextPrevPager($pager)
-	{
-		$style=$this->getPagerStyle();
-		$buttonType=$style->getButtonType();
-		$controls=$pager->getControls();
-		$currentPageIndex=$this->getCurrentPageIndex();
-		if($currentPageIndex===0)
-		{
-			if(($text=$style->getFirstPageText())!=='')
-			{
-				$label=$this->createPagerButton($pager,$buttonType,false,$text,'','');
-				$controls->add($label);
-				$controls->add("\n");
-			}
-
-			$label=$this->createPagerButton($pager,$buttonType,false,$style->getPrevPageText(),'','');
-			$controls->add($label);
-		}
-		else
-		{
-			if(($text=$style->getFirstPageText())!=='')
-			{
-				$button=$this->createPagerButton($pager,$buttonType,true,$text,self::CMD_PAGE,self::CMD_PAGE_FIRST);
-				$controls->add($button);
-				$controls->add("\n");
-			}
-
-			$button=$this->createPagerButton($pager,$buttonType,true,$style->getPrevPageText(),self::CMD_PAGE,self::CMD_PAGE_PREV);
-			$controls->add($button);
-		}
-		$controls->add("\n");
-		if($currentPageIndex===$this->getPageCount()-1)
-		{
-			$label=$this->createPagerButton($pager,$buttonType,false,$style->getNextPageText(),'','');
-			$controls->add($label);
-			if(($text=$style->getLastPageText())!=='')
-			{
-				$controls->add("\n");
-				$label=$this->createPagerButton($pager,$buttonType,false,$text,'','');
-				$controls->add($label);
-			}
-		}
-		else
-		{
-			$button=$this->createPagerButton($pager,$buttonType,true,$style->getNextPageText(),self::CMD_PAGE,self::CMD_PAGE_NEXT);
-			$controls->add($button);
-			if(($text=$style->getLastPageText())!=='')
-			{
-				$controls->add("\n");
-				$button=$this->createPagerButton($pager,$buttonType,true,$text,self::CMD_PAGE,self::CMD_PAGE_LAST);
-				$controls->add($button);
-			}
-		}
-	}
-
-	/**
-	 * Builds a numeric pager
-	 * @param TDataGridPager the container for the pager
-	 */
-	protected function buildNumericPager($pager)
-	{
-		$style=$this->getPagerStyle();
-		$buttonType=$style->getButtonType();
-		$controls=$pager->getControls();
-		$pageCount=$this->getPageCount();
-		$pageIndex=$this->getCurrentPageIndex()+1;
-		$maxButtonCount=$style->getPageButtonCount();
-		$buttonCount=$maxButtonCount>$pageCount?$pageCount:$maxButtonCount;
-		$startPageIndex=1;
-		$endPageIndex=$buttonCount;
-		if($pageIndex>$endPageIndex)
-		{
-			$startPageIndex=((int)(($pageIndex-1)/$maxButtonCount))*$maxButtonCount+1;
-			if(($endPageIndex=$startPageIndex+$maxButtonCount-1)>$pageCount)
-				$endPageIndex=$pageCount;
-			if($endPageIndex-$startPageIndex+1<$maxButtonCount)
-			{
-				if(($startPageIndex=$endPageIndex-$maxButtonCount+1)<1)
-					$startPageIndex=1;
-			}
-		}
-
-		if($startPageIndex>1)
-		{
-			if(($text=$style->getFirstPageText())!=='')
-			{
-				$button=$this->createPagerButton($pager,$buttonType,true,$text,self::CMD_PAGE,self::CMD_PAGE_FIRST);
-				$controls->add($button);
-				$controls->add("\n");
-			}
-			$prevPageIndex=$startPageIndex-1;
-			$button=$this->createPagerButton($pager,$buttonType,true,$style->getPrevPageText(),self::CMD_PAGE,"$prevPageIndex");
-			$controls->add($button);
-			$controls->add("\n");
-		}
-
-		for($i=$startPageIndex;$i<=$endPageIndex;++$i)
-		{
-			if($i===$pageIndex)
-			{
-				$label=$this->createPagerButton($pager,$buttonType,false,"$i",'','');
-				$controls->add($label);
-			}
-			else
-			{
-				$button=$this->createPagerButton($pager,$buttonType,true,"$i",self::CMD_PAGE,"$i");
-				$controls->add($button);
-			}
-			if($i<$endPageIndex)
-				$controls->add("\n");
-		}
-
-		if($pageCount>$endPageIndex)
-		{
-			$controls->add("\n");
-			$nextPageIndex=$endPageIndex+1;
-			$button=$this->createPagerButton($pager,$buttonType,true,$style->getNextPageText(),self::CMD_PAGE,"$nextPageIndex");
-			$controls->add($button);
-			if(($text=$style->getLastPageText())!=='')
-			{
-				$controls->add("\n");
-				$button=$this->createPagerButton($pager,$buttonType,true,$text,self::CMD_PAGE,self::CMD_PAGE_LAST);
-				$controls->add($button);
-			}
-		}
-	}
-
-	/**
-	 * Automatically generates datagrid columns based on datasource schema
-	 * @param Traversable data source bound to the datagrid
-	 * @return TDataGridColumnCollection
-	 */
-	protected function createAutoColumns($dataSource)
-	{
-		if(!$dataSource)
-			return null;
-		$autoColumns=$this->getAutoColumns();
-		$autoColumns->clear();
-		foreach($dataSource as $row)
-		{
-			foreach($row as $key=>$value)
-			{
-				$column=new $this->AutoGenerateColumnName;
-				if(is_string($key))
-				{
-					$column->setHeaderText($key);
-					$column->setDataField($key);
-					$column->setSortExpression($key);
-					$autoColumns->add($column);
-				}
-				else
-				{
-					$column->setHeaderText(TListItemType::Item);
-					$column->setDataField($key);
-					$column->setSortExpression(TListItemType::Item);
-					$autoColumns->add($column);
-				}
-			}
-			break;
-		}
-		return $autoColumns;
-	}
-
-	/**
-	 * Applies styles to items, header, footer and separators.
-	 * Item styles are applied in a hierarchical way. Style in higher hierarchy
-	 * will inherit from styles in lower hierarchy.
-	 * Starting from the lowest hierarchy, the item styles include
-	 * item's own style, {@link getItemStyle ItemStyle}, {@link getAlternatingItemStyle AlternatingItemStyle},
-	 * {@link getSelectedItemStyle SelectedItemStyle}, and {@link getEditItemStyle EditItemStyle}.
-	 * Therefore, if background color is set as red in {@link getItemStyle ItemStyle},
-	 * {@link getEditItemStyle EditItemStyle} will also have red background color
-	 * unless it is set to a different value explicitly.
-	 */
-	protected function applyItemStyles()
-	{
-		$itemStyle=$this->getViewState('ItemStyle',null);
-
-		$alternatingItemStyle=$this->getViewState('AlternatingItemStyle',null);
-		if($itemStyle!==null)
-		{
-			if($alternatingItemStyle===null)
-				$alternatingItemStyle=$itemStyle;
-			else
-				$alternatingItemStyle->mergeWith($itemStyle);
-		}
-
-		$selectedItemStyle=$this->getViewState('SelectedItemStyle',null);
-
-		$editItemStyle=$this->getViewState('EditItemStyle',null);
-		if($selectedItemStyle!==null)
-		{
-			if($editItemStyle===null)
-				$editItemStyle=$selectedItemStyle;
-			else
-				$editItemStyle->mergeWith($selectedItemStyle);
-		}
-
-		$headerStyle=$this->getViewState('HeaderStyle',null);
-		$footerStyle=$this->getViewState('FooterStyle',null);
-		$pagerStyle=$this->getViewState('PagerStyle',null);
-		$separatorStyle=$this->getViewState('SeparatorStyle',null);
-
-		foreach($this->getControls() as $index=>$item)
-		{
-			if(!($item instanceof TDataGridItem) && !($item instanceof TDataGridPager))
-				continue;
-			$itemType=$item->getItemType();
-			switch($itemType)
-			{
-				case TListItemType::Header:
-					if($headerStyle)
-						$item->getStyle()->mergeWith($headerStyle);
-					if(!$this->getShowHeader())
-						$item->setVisible(false);
-					break;
-				case TListItemType::Footer:
-					if($footerStyle)
-						$item->getStyle()->mergeWith($footerStyle);
-					if(!$this->getShowFooter())
-						$item->setVisible(false);
-					break;
-				case TListItemType::Separator:
-					if($separatorStyle)
-						$item->getStyle()->mergeWith($separatorStyle);
-					break;
-				case TListItemType::Item:
-					if($itemStyle)
-						$item->getStyle()->mergeWith($itemStyle);
-					break;
-				case TListItemType::AlternatingItem:
-					if($alternatingItemStyle)
-						$item->getStyle()->mergeWith($alternatingItemStyle);
-					break;
-				case TListItemType::SelectedItem:
-					if($selectedItemStyle)
-						$item->getStyle()->mergeWith($selectedItemStyle);
-					if($index % 2==1)
-					{
-						if($itemStyle)
-							$item->getStyle()->mergeWith($itemStyle);
-					}
-					else
-					{
-						if($alternatingItemStyle)
-							$item->getStyle()->mergeWith($alternatingItemStyle);
-					}
-					break;
-				case TListItemType::EditItem:
-					if($editItemStyle)
-						$item->getStyle()->mergeWith($editItemStyle);
-					if($index % 2==1)
-					{
-						if($itemStyle)
-							$item->getStyle()->mergeWith($itemStyle);
-					}
-					else
-					{
-						if($alternatingItemStyle)
-							$item->getStyle()->mergeWith($alternatingItemStyle);
-					}
-					break;
-				case TListItemType::Pager:
-					if($pagerStyle)
-					{
-						$item->getStyle()->mergeWith($pagerStyle);
-						if($index===0)
-						{
-							if($pagerStyle->getPosition()===TDataGridPagerPosition::Bottom || !$pagerStyle->getVisible())
-								$item->setVisible(false);
-						}
-						else
-						{
-							if($pagerStyle->getPosition()===TDataGridPagerPosition::Top || !$pagerStyle->getVisible())
-								$item->setVisible(false);
-						}
-					}
-					break;
-				default:
-					break;
-			}
-			if($this->_columns && $itemType!==TListItemType::Pager)
-			{
-				$n=$this->_columns->getCount();
-				$cells=$item->getCells();
-				for($i=0;$i<$n;++$i)
-				{
-					$cell=$cells->itemAt($i);
-					$column=$this->_columns->itemAt($i);
-					if(!$column->getVisible())
-						$cell->setVisible(false);
-					else
-					{
-						if($itemType===TListItemType::Header)
-							$style=$column->getHeaderStyle(false);
-						else if($itemType===TListItemType::Footer)
-							$style=$column->getFooterStyle(false);
-						else
-							$style=$column->getItemStyle(false);
-						if($style!==null)
-							$cell->getStyle()->mergeWith($style);
-					}
-				}
-			}
-		}
-	}
-
-	/**
-	 * Renders the openning tag for the datagrid control which will render table caption if present.
-	 * @param THtmlWriter the writer used for the rendering purpose
-	 */
-	public function renderBeginTag($writer)
-	{
-		parent::renderBeginTag($writer);
-		if(($caption=$this->getCaption())!=='')
-		{
-			if(($align=$this->getCaptionAlign())!==TTableCaptionAlign::NotSet)
-				$writer->addAttribute('align',strtolower($align));
-			$writer->renderBeginTag('caption');
-			$writer->write($caption);
-			$writer->renderEndTag();
-		}
-	}
-
-	/**
-	 * Renders the datagrid.
-	 * @param THtmlWriter writer for the rendering purpose
-	 */
-	public function render($writer)
-	{
-		if($this->getHasControls())
-		{
-			$this->groupCells();
-			if($this->_useEmptyTemplate)
-			{
-				$control=new TWebControl;
-				$control->setID($this->getClientID());
-				$control->copyBaseAttributes($this);
-				if($this->getHasStyle())
-					$control->getStyle()->copyFrom($this->getStyle());
-				$control->renderBeginTag($writer);
-				$this->renderContents($writer);
-				$control->renderEndTag($writer);
-			}
-			else if($this->getViewState('ItemCount',0)>0)
-			{
-				$this->applyItemStyles();
-				if($this->_topPager)
-				{
-					$this->_topPager->renderControl($writer);
-					$writer->writeLine();
-				}
-				$this->renderTable($writer);
-				if($this->_bottomPager)
-				{
-					$writer->writeLine();
-					$this->_bottomPager->renderControl($writer);
-				}
-			}
-		}
-	}
-
-	/**
-	 * Renders the tabular data.
-	 * @param THtmlWriter writer
-	 */
-	protected function renderTable($writer)
-	{
-		$this->renderBeginTag($writer);
-		if($this->_header && $this->_header->getVisible())
-		{
-			$writer->writeLine();
-			if($style=$this->getViewState('TableHeadStyle',null))
-				$style->addAttributesToRender($writer);
-			$writer->renderBeginTag('thead');
-			$this->_header->render($writer);
-			$writer->renderEndTag();
-		}
-		$writer->writeLine();
-		if($style=$this->getViewState('TableBodyStyle',null))
-			$style->addAttributesToRender($writer);
-		$writer->renderBeginTag('tbody');
-		foreach($this->getItems() as $item)
-			$item->renderControl($writer);
-		$writer->renderEndTag();
-
-		if($this->_footer && $this->_footer->getVisible())
-		{
-			$writer->writeLine();
-			if($style=$this->getViewState('TableFootStyle',null))
-				$style->addAttributesToRender($writer);
-			$writer->renderBeginTag('tfoot');
-			$this->_footer->render($writer);
-			$writer->renderEndTag();
-		}
-
-		$writer->writeLine();
-		$this->renderEndTag($writer);
-	}
-}
-
-/**
- * TDataGridItemEventParameter class
- *
- * TDataGridItemEventParameter encapsulates the parameter data for
- * {@link TDataGrid::onItemCreated OnItemCreated} event of {@link TDataGrid} controls.
- * The {@link getItem Item} property indicates the datagrid item related with the event.
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id$
- * @package System.Web.UI.WebControls
- * @since 3.0
- */
-class TDataGridItemEventParameter extends TEventParameter
-{
-	/**
-	 * The TDataGridItem control responsible for the event.
-	 * @var TDataGridItem
-	 */
-	private $_item=null;
-
-	/**
-	 * Constructor.
-	 * @param TDataGridItem datagrid item related with the corresponding event
-	 */
-	public function __construct(TDataGridItem $item)
-	{
-		$this->_item=$item;
-	}
-
-	/**
-	 * @return TDataGridItem datagrid item related with the corresponding event
-	 */
-	public function getItem()
-	{
-		return $this->_item;
-	}
-}
-
-/**
- * TDataGridPagerEventParameter class
- *
- * TDataGridPagerEventParameter encapsulates the parameter data for
- * {@link TDataGrid::onPagerCreated OnPagerCreated} event of {@link TDataGrid} controls.
- * The {@link getPager Pager} property indicates the datagrid pager related with the event.
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id$
- * @package System.Web.UI.WebControls
- * @since 3.0
- */
-class TDataGridPagerEventParameter extends TEventParameter
-{
-	/**
-	 * The TDataGridPager control responsible for the event.
-	 * @var TDataGridPager
-	 */
-	protected $_pager=null;
-
-	/**
-	 * Constructor.
-	 * @param TDataGridPager datagrid pager related with the corresponding event
-	 */
-	public function __construct(TDataGridPager $pager)
-	{
-		$this->_pager=$pager;
-	}
-
-	/**
-	 * @return TDataGridPager datagrid pager related with the corresponding event
-	 */
-	public function getPager()
-	{
-		return $this->_pager;
-	}
-}
-
-/**
- * TDataGridCommandEventParameter class
- *
- * TDataGridCommandEventParameter encapsulates the parameter data for
- * {@link TDataGrid::onItemCommand ItemCommand} event of {@link TDataGrid} controls.
- *
- * The {@link getItem Item} property indicates the datagrid item related with the event.
- * The {@link getCommandSource CommandSource} refers to the control that originally
- * raises the Command event.
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id$
- * @package System.Web.UI.WebControls
- * @since 3.0
- */
-class TDataGridCommandEventParameter extends TCommandEventParameter
-{
-	/**
-	 * @var TDataGridItem the TDataGridItem control responsible for the event.
-	 */
-	private $_item=null;
-	/**
-	 * @var TControl the control originally raises the <b>Command</b> event.
-	 */
-	private $_source=null;
-
-	/**
-	 * Constructor.
-	 * @param TDataGridItem datagrid item responsible for the event
-	 * @param TControl original event sender
-	 * @param TCommandEventParameter original event parameter
-	 */
-	public function __construct($item,$source,TCommandEventParameter $param)
-	{
-		$this->_item=$item;
-		$this->_source=$source;
-		parent::__construct($param->getCommandName(),$param->getCommandParameter());
-	}
-
-	/**
-	 * @return TDataGridItem the TDataGridItem control responsible for the event.
-	 */
-	public function getItem()
-	{
-		return $this->_item;
-	}
-
-	/**
-	 * @return TControl the control originally raises the <b>Command</b> event.
-	 */
-	public function getCommandSource()
-	{
-		return $this->_source;
-	}
-}
-
-/**
- * TDataGridSortCommandEventParameter class
- *
- * TDataGridSortCommandEventParameter encapsulates the parameter data for
- * {@link TDataGrid::onSortCommand SortCommand} event of {@link TDataGrid} controls.
- *
- * The {@link getCommandSource CommandSource} property refers to the control
- * that originally raises the OnCommand event, while {@link getSortExpression SortExpression}
- * gives the sort expression carried with the sort command.
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id$
- * @package System.Web.UI.WebControls
- * @since 3.0
- */
-class TDataGridSortCommandEventParameter extends TEventParameter
-{
-	/**
-	 * @var string sort expression
-	 */
-	private $_sortExpression='';
-	/**
-	 * @var TControl original event sender
-	 */
-	private $_source=null;
-
-	/**
-	 * Constructor.
-	 * @param TControl the control originally raises the <b>OnCommand</b> event.
-	 * @param TDataGridCommandEventParameter command event parameter
-	 */
-	public function __construct($source,TDataGridCommandEventParameter $param)
-	{
-		$this->_source=$source;
-		$this->_sortExpression=$param->getCommandParameter();
-	}
-
-	/**
-	 * @return TControl the control originally raises the <b>OnCommand</b> event.
-	 */
-	public function getCommandSource()
-	{
-		return $this->_source;
-	}
-
-	/**
-	 * @return string sort expression
-	 */
-	public function getSortExpression()
-	{
-		return $this->_sortExpression;
-	}
-}
-
-/**
- * TDataGridPageChangedEventParameter class
- *
- * TDataGridPageChangedEventParameter encapsulates the parameter data for
- * {@link TDataGrid::onPageIndexChanged PageIndexChanged} event of {@link TDataGrid} controls.
- *
- * The {@link getCommandSource CommandSource} property refers to the control
- * that originally raises the OnCommand event, while {@link getNewPageIndex NewPageIndex}
- * returns the new page index carried with the page command.
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id$
- * @package System.Web.UI.WebControls
- * @since 3.0
- */
-class TDataGridPageChangedEventParameter extends TEventParameter
-{
-	/**
-	 * @var integer new page index
-	 */
-	private $_newIndex;
-	/**
-	 * @var TControl original event sender
-	 */
-	private $_source=null;
-
-	/**
-	 * Constructor.
-	 * @param TControl the control originally raises the <b>OnCommand</b> event.
-	 * @param integer new page index
-	 */
-	public function __construct($source,$newPageIndex)
-	{
-		$this->_source=$source;
-		$this->_newIndex=$newPageIndex;
-	}
-
-	/**
-	 * @return TControl the control originally raises the <b>OnCommand</b> event.
-	 */
-	public function getCommandSource()
-	{
-		return $this->_source;
-	}
-
-	/**
-	 * @return integer new page index
-	 */
-	public function getNewPageIndex()
-	{
-		return $this->_newIndex;
-	}
-}
-
-/**
- * TDataGridItem class
- *
- * A TDataGridItem control represents an item in the {@link TDataGrid} control,
- * such as heading section, footer section, or a data item.
- * The index and data value of the item can be accessed via {@link getItemIndex ItemIndex}>
- * and {@link getDataItem DataItem} properties, respectively. The type of the item
- * is given by {@link getItemType ItemType} property. Property {@link getDataSourceIndex DataSourceIndex}
- * gives the index of the item from the bound data source.
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id$
- * @package System.Web.UI.WebControls
- * @since 3.0
- */
-class TDataGridItem extends TTableRow implements INamingContainer
-{
-	/**
-	 * @var integer index of the data item in the Items collection of datagrid
-	 */
-	private $_itemIndex='';
-	/**
-	 * @var integer index of the item from the bound data source
-	 */
-	private $_dataSourceIndex=0;
-	/**
-	 * type of the TDataGridItem
-	 * @var string
-	 */
-	private $_itemType='';
-	/**
-	 * value of the data item
-	 * @var mixed
-	 */
-	private $_data=null;
-
-	/**
-	 * Constructor.
-	 * @param integer zero-based index of the item in the item collection of datagrid
-	 * @param TListItemType item type
-	 */
-	public function __construct($itemIndex,$dataSourceIndex,$itemType)
-	{
-		$this->_itemIndex=$itemIndex;
-		$this->_dataSourceIndex=$dataSourceIndex;
-		$this->setItemType($itemType);
-		if($itemType===TListItemType::Header)
-			$this->setTableSection(TTableRowSection::Header);
-		else if($itemType===TListItemType::Footer)
-			$this->setTableSection(TTableRowSection::Footer);
-	}
-
-	/**
-	 * @return TListItemType item type.
-	 */
-	public function getItemType()
-	{
-		return $this->_itemType;
-	}
-
-	/**
-	 * @param TListItemType item type
-	 */
-	public function setItemType($value)
-	{
-		$this->_itemType=TPropertyValue::ensureEnum($value,'TListItemType');
-	}
-
-	/**
-	 * @return integer zero-based index of the item in the item collection of datagrid
-	 */
-	public function getItemIndex()
-	{
-		return $this->_itemIndex;
-	}
-
-	/**
-	 * @return integer the index of the datagrid item from the bound data source
-	 */
-	public function getDataSourceIndex()
-	{
-		return $this->_dataSourceIndex;
-	}
-
-	/**
-	 * @return mixed data associated with the item
-	 * @since 3.1.0
-	 */
-	public function getData()
-	{
-		return $this->_data;
-	}
-
-	/**
-	 * @param mixed data to be associated with the item
-	 * @since 3.1.0
-	 */
-	public function setData($value)
-	{
-		$this->_data=$value;
-	}
-
-	/**
-	 * This property is deprecated since v3.1.0.
-	 * @return mixed data associated with the item
-	 * @deprecated deprecated since v3.1.0. Use {@link getData} instead.
-	 */
-	public function getDataItem()
-	{
-		return $this->getData();
-	}
-
-	/**
-	 * This property is deprecated since v3.1.0.
-	 * @param mixed data to be associated with the item
-	 * @deprecated deprecated since version 3.1.0. Use {@link setData} instead.
-	 */
-	public function setDataItem($value)
-	{
-		return $this->setData($value);
-	}
-
-	/**
-	 * This method overrides parent's implementation by wrapping event parameter
-	 * for <b>OnCommand</b> event with item information.
-	 * @param TControl the sender of the event
-	 * @param TEventParameter event parameter
-	 * @return boolean whether the event bubbling should stop here.
-	 */
-	public function bubbleEvent($sender,$param)
-	{
-		if($param instanceof TCommandEventParameter)
-		{
-			$this->raiseBubbleEvent($this,new TDataGridCommandEventParameter($this,$sender,$param));
-			return true;
-		}
-		else
-			return false;
-	}
-}
-
-
-/**
- * TDataGridPager class.
- *
- * TDataGridPager represents a datagrid pager.
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id$
- * @package System.Web.UI.WebControls
- * @since 3.0
- */
-class TDataGridPager extends TPanel implements INamingContainer
-{
-	private $_dataGrid;
-
-	/**
-	 * Constructor.
-	 * @param TDataGrid datagrid object
-	 */
-	public function __construct($dataGrid)
-	{
-		$this->_dataGrid=$dataGrid;
-	}
-
-	/**
-	 * This method overrides parent's implementation by wrapping event parameter
-	 * for <b>OnCommand</b> event with item information.
-	 * @param TControl the sender of the event
-	 * @param TEventParameter event parameter
-	 * @return boolean whether the event bubbling should stop here.
-	 */
-	public function bubbleEvent($sender,$param)
-	{
-		if($param instanceof TCommandEventParameter)
-		{
-			$this->raiseBubbleEvent($this,new TDataGridCommandEventParameter($this,$sender,$param));
-			return true;
-		}
-		else
-			return false;
-	}
-
-	/**
-	 * @return TDataGrid the datagrid owning this pager
-	 */
-	public function getDataGrid()
-	{
-		return $this->_dataGrid;
-	}
-
-	/**
-	 * @return string item type.
-	 */
-	public function getItemType()
-	{
-		return TListItemType::Pager;
-	}
-}
-
-
-/**
- * TDataGridItemCollection class.
- *
- * TDataGridItemCollection represents a collection of data grid items.
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id$
- * @package System.Web.UI.WebControls
- * @since 3.0
- */
-class TDataGridItemCollection extends TList
-{
-	/**
-	 * Inserts an item at the specified position.
-	 * This overrides the parent implementation by inserting only TDataGridItem.
-	 * @param integer the speicified position.
-	 * @param mixed new item
-	 * @throws TInvalidDataTypeException if the item to be inserted is not a TDataGridItem.
-	 */
-	public function insertAt($index,$item)
-	{
-		if($item instanceof TDataGridItem)
-			parent::insertAt($index,$item);
-		else
-			throw new TInvalidDataTypeException('datagriditemcollection_datagriditem_required');
-	}
-}
-
-/**
- * TDataGridColumnCollection class.
- *
- * TDataGridColumnCollection represents a collection of data grid columns.
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id$
- * @package System.Web.UI.WebControls
- * @since 3.0
- */
-class TDataGridColumnCollection extends TList
-{
-	/**
-	 * the control that owns this collection.
-	 * @var TControl
-	 */
-	private $_o;
-
-	/**
-	 * Constructor.
-	 * @param TDataGrid the control that owns this collection.
-	 */
-	public function __construct(TDataGrid $owner)
-	{
-		$this->_o=$owner;
-	}
-
-	/**
-	 * @return TDataGrid the control that owns this collection.
-	 */
-	protected function getOwner()
-	{
-		return $this->_o;
-	}
-
-	/**
-	 * Inserts an item at the specified position.
-	 * This overrides the parent implementation by inserting only TDataGridColumn.
-	 * @param integer the speicified position.
-	 * @param mixed new item
-	 * @throws TInvalidDataTypeException if the item to be inserted is not a TDataGridColumn.
-	 */
-	public function insertAt($index,$item)
-	{
-		if($item instanceof TDataGridColumn)
-		{
-			$item->setOwner($this->_o);
-			parent::insertAt($index,$item);
-		}
-		else
-			throw new TInvalidDataTypeException('datagridcolumncollection_datagridcolumn_required');
-	}
-}
-
-/**
- * TDataGridPagerMode class.
- * TDataGridPagerMode defines the enumerable type for the possible modes that a datagrid pager can take.
- *
- * The following enumerable values are defined:
- * - NextPrev: pager buttons are displayed as next and previous pages
- * - Numeric: pager buttons are displayed as numeric page numbers
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id$
- * @package System.Web.UI.WebControls
- * @since 3.0.4
- */
-class TDataGridPagerMode extends TEnumerable
-{
-	const NextPrev='NextPrev';
-	const Numeric='Numeric';
-}
-
-
-/**
- * TDataGridPagerButtonType class.
- * TDataGridPagerButtonType defines the enumerable type for the possible types of datagrid pager buttons.
- *
- * The following enumerable values are defined:
- * - LinkButton: link buttons
- * - PushButton: form submit buttons
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id$
- * @package System.Web.UI.WebControls
- * @since 3.0.4
- */
-class TDataGridPagerButtonType extends TEnumerable
-{
-	const LinkButton='LinkButton';
-	const PushButton='PushButton';
-}
-
-
-/**
- * TDataGridPagerPosition class.
- * TDataGridPagerPosition defines the enumerable type for the possible positions that a datagrid pager can be located at.
- *
- * The following enumerable values are defined:
- * - Bottom: pager appears only at the bottom of the data grid.
- * - Top: pager appears only at the top of the data grid.
- * - TopAndBottom: pager appears on both top and bottom of the data grid.
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id$
- * @package System.Web.UI.WebControls
- * @since 3.0.4
- */
-class TDataGridPagerPosition extends TEnumerable
-{
-	const Bottom='Bottom';
-	const Top='Top';
-	const TopAndBottom='TopAndBottom';
-}
-
+<?php
+/**
+ * TDataGrid related class files.
+ * This file contains the definition of the following classes:
+ * TDataGrid, TDataGridItem, TDataGridItemCollection, TDataGridColumnCollection,
+ * TDataGridPagerStyle, TDataGridItemEventParameter,
+ * TDataGridCommandEventParameter, TDataGridSortCommandEventParameter,
+ * TDataGridPageChangedEventParameter
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @link http://www.pradosoft.com/
+ * @copyright Copyright &copy; 2005-2012 PradoSoft
+ * @license http://www.pradosoft.com/license/
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ */
+
+/**
+ * Includes TBaseList, TPagedDataSource, TDummyDataSource and TTable classes
+ */
+Prado::using('System.Web.UI.WebControls.TBaseDataList');
+Prado::using('System.Collections.TPagedDataSource');
+Prado::using('System.Collections.TDummyDataSource');
+Prado::using('System.Web.UI.WebControls.TTable');
+Prado::using('System.Web.UI.WebControls.TPanel');
+Prado::using('System.Web.UI.WebControls.TDataGridPagerStyle');
+
+/**
+ * TDataGrid class
+ *
+ * TDataGrid represents a data bound and updatable grid control.
+ *
+ * To populate data into the datagrid, sets its {@link setDataSource DataSource}
+ * to a tabular data source and call {@link dataBind()}.
+ * Each row of data will be represented by an item in the {@link getItems Items}
+ * collection of the datagrid.
+ *
+ * An item can be at one of three states: browsing, selected and edit.
+ * The state determines how the item will be displayed. For example, if an item
+ * is in edit state, it may be displayed as a table row with input text boxes
+ * if the columns are of type {@link TBoundColumn}; and if in browsing state,
+ * they are displayed as static text.
+ *
+ * To change the state of an item, set {@link setEditItemIndex EditItemIndex}
+ * or {@link setSelectedItemIndex SelectedItemIndex} property.
+ *
+ * Each datagrid item has a {@link TDataGridItem::getItemType type}
+ * which tells the position and state of the item in the datalist. An item in the header
+ * of the repeater is of type Header. A body item may be of either
+ * Item, AlternatingItem, SelectedItem or EditItem, depending whether the item
+ * index is odd or even, whether it is being selected or edited.
+ *
+ * A datagrid is specified with a list of columns. Each column specifies how the corresponding
+ * table column will be displayed. For example, the header/footer text of that column,
+ * the cells in that column, and so on. The following column types are currently
+ * provided by the framework,
+ * - {@link TBoundColumn}, associated with a specific field in datasource and displays the corresponding data.
+ * - {@link TEditCommandColumn}, displaying edit/update/cancel command buttons
+ * - {@link TButtonColumn}, displaying generic command buttons that may be bound to specific field in datasource.
+ * - {@link TDropDownListColumn}, displaying a dropdown list when the item is in edit state
+ * - {@link THyperLinkColumn}, displaying a hyperlink that may be bound to specific field in datasource.
+ * - {@link TCheckBoxColumn}, displaying a checkbox that may be bound to specific field in datasource.
+ * - {@link TTemplateColumn}, displaying content based on templates.
+ *
+ * There are three ways to specify columns for a datagrid.
+ * <ul>
+ *  <li>Automatically generated based on data source.
+ *  By setting {@link setAutoGenerateColumns AutoGenerateColumns} to true,
+ *  a list of columns will be automatically generated based on the schema of the data source.
+ *  Each column corresponds to a column of the data.</li>
+ *  <li>Specified in template. For example,
+ *    <code>
+ *     <com:TDataGrid ...>
+ *        <com:TBoundColumn .../>
+ *        <com:TEditCommandColumn .../>
+ *     </com:TDataGrid>
+ *    </code>
+ *  </li>
+ *  <li>Manually created in code. Columns can be manipulated via
+ *  the {@link setColumns Columns} property of the datagrid. For example,
+ *  <code>
+ *    $column=new TBoundColumn;
+ *    $datagrid->Columns[]=$column;
+ *  </code>
+ *  </li>
+ * </ul>
+ * Note, automatically generated columns cannot be accessed via
+ * the {@link getColumns Columns} property.
+ *
+ * TDataGrid supports sorting. If the {@link setAllowSorting AllowSorting}
+ * is set to true, a column with nonempty {@link setSortExpression SortExpression}
+ * will have its header text displayed as a clickable link button.
+ * Clicking on the link button will raise {@link onSortCommand OnSortCommand}
+ * event. You can respond to this event, sort the data source according
+ * to the event parameter, and then invoke {@link databind()} on the datagrid
+ * to show to end users the sorted data.
+ *
+ * TDataGrid supports paging. If the {@link setAllowPaging AllowPaging}
+ * is set to true, a pager will be displayed on top and/or bottom of the table.
+ * How the pager will be displayed is determined by the {@link getPagerStyle PagerStyle}
+ * property. Clicking on a pager button will raise an {@link onPageIndexChanged OnPageIndexChanged}
+ * event. You can respond to this event, specify the page to be displayed by
+ * setting {@link setCurrentPageIndex CurrentPageIndex}</b> property,
+ * and then invoke {@link databind()} on the datagrid to show to end users
+ * a new page of data.
+ *
+ * TDataGrid supports two kinds of paging. The first one is based on the number of data items in
+ * datasource. The number of pages {@link getPageCount PageCount} is calculated based
+ * the item number and the {@link setPageSize PageSize} property.
+ * The datagrid will manage which section of the data source to be displayed
+ * based on the {@link setCurrentPageIndex CurrentPageIndex} property.
+ * The second approach calculates the page number based on the
+ * {@link setVirtualItemCount VirtualItemCount} property and
+ * the {@link setPageSize PageSize} property. The datagrid will always
+ * display from the beginning of the datasource up to the number of
+ * {@link setPageSize PageSize} data items. This approach is especially
+ * useful when the datasource may contain too many data items to be managed by
+ * the datagrid efficiently.
+ *
+ * When the datagrid contains a button control that raises an {@link onCommand OnCommand}
+ * event, the event will be bubbled up to the datagrid control.
+ * If the event's command name is recognizable by the datagrid control,
+ * a corresponding item event will be raised. The following item events will be
+ * raised upon a specific command:
+ * - OnEditCommand, if CommandName=edit
+ * - OnCancelCommand, if CommandName=cancel
+ * - OnSelectCommand, if CommandName=select
+ * - OnDeleteCommand, if CommandName=delete
+ * - OnUpdateCommand, if CommandName=update
+ * - onPageIndexChanged, if CommandName=page
+ * - OnSortCommand, if CommandName=sort
+ * Note, an {@link onItemCommand OnItemCommand} event is raised in addition to
+ * the above specific command events.
+ *
+ * TDataGrid also raises an {@link onItemCreated OnItemCreated} event for
+ * every newly created datagrid item. You can respond to this event to customize
+ * the content or style of the newly created item.
+ *
+ * Note, the data bound to the datagrid are reset to null after databinding.
+ * There are several ways to access the data associated with a datagrid row:
+ * - Access the data in {@link onItemDataBound OnItemDataBound} event
+ * - Use {@link getDataKeys DataKeys} to obtain the data key associated with
+ * the specified datagrid row and use the key to fetch the corresponding data
+ * from some persistent storage such as DB.
+ * - Save the data in viewstate and get it back during postbacks.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ * @since 3.0
+ */
+class TDataGrid extends TBaseDataList implements INamingContainer
+{
+	/**
+	 * datagrid item types
+	 * @deprecated deprecated since version 3.0.4. Use TListItemType constants instead.
+	 */
+	const IT_HEADER='Header';
+	const IT_FOOTER='Footer';
+	const IT_ITEM='Item';
+	const IT_SEPARATOR='Separator';
+	const IT_ALTERNATINGITEM='AlternatingItem';
+	const IT_EDITITEM='EditItem';
+	const IT_SELECTEDITEM='SelectedItem';
+	const IT_PAGER='Pager';
+
+	/**
+	 * Command name that TDataGrid understands.
+	 */
+	const CMD_SELECT='Select';
+	const CMD_EDIT='Edit';
+	const CMD_UPDATE='Update';
+	const CMD_DELETE='Delete';
+	const CMD_CANCEL='Cancel';
+	const CMD_SORT='Sort';
+	const CMD_PAGE='Page';
+	const CMD_PAGE_NEXT='Next';
+	const CMD_PAGE_PREV='Previous';
+	const CMD_PAGE_FIRST='First';
+	const CMD_PAGE_LAST='Last';
+
+	/**
+	 * @var TDataGridColumnCollection manually created column collection
+	 */
+	private $_columns=null;
+	/**
+	 * @var TDataGridColumnCollection automatically created column collection
+	 */
+	private $_autoColumns=null;
+	/**
+	 * @var TList all columns including both manually and automatically created columns
+	 */
+	private $_allColumns=null;
+	/**
+	 * @var TDataGridItemCollection datagrid item collection
+	 */
+	private $_items=null;
+	/**
+	 * @var TDataGridItem header item
+	 */
+	private $_header=null;
+	/**
+	 * @var TDataGridItem footer item
+	 */
+	private $_footer=null;
+	/**
+	 * @var TPagedDataSource paged data source object
+	 */
+	private $_pagedDataSource=null;
+	private $_topPager=null;
+	private $_bottomPager=null;
+	/**
+	 * @var ITemplate template used when empty data is bounded
+	 */
+	private $_emptyTemplate=null;
+	/**
+	 * @var boolean whether empty template is effective
+	 */
+	private $_useEmptyTemplate=false;
+
+	/**
+	 * @return string tag name (table) of the datagrid
+	 */
+	protected function getTagName()
+	{
+		return 'table';
+	}
+
+	/**
+	 * @return string Name of the class used in AutoGenerateColumns mode
+	 */
+	protected function getAutoGenerateColumnName()
+	{
+		return 'TBoundColumn';
+	}
+
+	/**
+	 * Adds objects parsed in template to datagrid.
+	 * Datagrid columns are added into {@link getColumns Columns} collection.
+	 * @param mixed object parsed in template
+	 */
+	public function addParsedObject($object)
+	{
+		if($object instanceof TDataGridColumn)
+			$this->getColumns()->add($object);
+		else
+			parent::addParsedObject($object);  // this is needed by EmptyTemplate
+	}
+
+	/**
+	 * @return TDataGridColumnCollection manually specified datagrid columns
+	 */
+	public function getColumns()
+	{
+		if(!$this->_columns)
+			$this->_columns=new TDataGridColumnCollection($this);
+		return $this->_columns;
+	}
+
+	/**
+	 * @return TDataGridColumnCollection automatically generated datagrid columns
+	 */
+	public function getAutoColumns()
+	{
+		if(!$this->_autoColumns)
+			$this->_autoColumns=new TDataGridColumnCollection($this);
+		return $this->_autoColumns;
+	}
+
+	/**
+	 * @return TDataGridItemCollection datagrid item collection
+	 */
+	public function getItems()
+	{
+		if(!$this->_items)
+			$this->_items=new TDataGridItemCollection;
+		return $this->_items;
+	}
+
+	/**
+	 * @return integer number of items
+	 */
+	public function getItemCount()
+	{
+		return $this->_items?$this->_items->getCount():0;
+	}
+
+	/**
+	 * Creates a style object for the control.
+	 * This method creates a {@link TTableStyle} to be used by datagrid.
+	 * @return TTableStyle control style to be used
+	 */
+	protected function createStyle()
+	{
+		return new TTableStyle;
+	}
+
+	/**
+	 * @return string the URL of the background image for the datagrid
+	 */
+	public function getBackImageUrl()
+	{
+		return $this->getStyle()->getBackImageUrl();
+	}
+
+	/**
+	 * @param string the URL of the background image for the datagrid
+	 */
+	public function setBackImageUrl($value)
+	{
+		$this->getStyle()->setBackImageUrl($value);
+	}
+
+	/**
+	 * @return TTableItemStyle the style for every item
+	 */
+	public function getItemStyle()
+	{
+		if(($style=$this->getViewState('ItemStyle',null))===null)
+		{
+			$style=new TTableItemStyle;
+			$this->setViewState('ItemStyle',$style,null);
+		}
+		return $style;
+	}
+
+	/**
+	 * @return TTableItemStyle the style for each alternating item
+	 */
+	public function getAlternatingItemStyle()
+	{
+		if(($style=$this->getViewState('AlternatingItemStyle',null))===null)
+		{
+			$style=new TTableItemStyle;
+			$this->setViewState('AlternatingItemStyle',$style,null);
+		}
+		return $style;
+	}
+
+	/**
+	 * @return TTableItemStyle the style for selected item
+	 */
+	public function getSelectedItemStyle()
+	{
+		if(($style=$this->getViewState('SelectedItemStyle',null))===null)
+		{
+			$style=new TTableItemStyle;
+			$this->setViewState('SelectedItemStyle',$style,null);
+		}
+		return $style;
+	}
+
+	/**
+	 * @return TTableItemStyle the style for edit item
+	 */
+	public function getEditItemStyle()
+	{
+		if(($style=$this->getViewState('EditItemStyle',null))===null)
+		{
+			$style=new TTableItemStyle;
+			$this->setViewState('EditItemStyle',$style,null);
+		}
+		return $style;
+	}
+
+	/**
+	 * @return TTableItemStyle the style for header
+	 */
+	public function getHeaderStyle()
+	{
+		if(($style=$this->getViewState('HeaderStyle',null))===null)
+		{
+			$style=new TTableItemStyle;
+			$this->setViewState('HeaderStyle',$style,null);
+		}
+		return $style;
+	}
+
+	/**
+	 * @return TTableItemStyle the style for footer
+	 */
+	public function getFooterStyle()
+	{
+		if(($style=$this->getViewState('FooterStyle',null))===null)
+		{
+			$style=new TTableItemStyle;
+			$this->setViewState('FooterStyle',$style,null);
+		}
+		return $style;
+	}
+
+	/**
+	 * @return TDataGridPagerStyle the style for pager
+	 */
+	public function getPagerStyle()
+	{
+		if(($style=$this->getViewState('PagerStyle',null))===null)
+		{
+			$style=new TDataGridPagerStyle;
+			$this->setViewState('PagerStyle',$style,null);
+		}
+		return $style;
+	}
+
+	/**
+	 * @return TStyle the style for thead element, if any
+	 * @since 3.1.1
+	 */
+	public function getTableHeadStyle()
+	{
+		if(($style=$this->getViewState('TableHeadStyle',null))===null)
+		{
+			$style=new TStyle;
+			$this->setViewState('TableHeadStyle',$style,null);
+		}
+		return $style;
+	}
+
+	/**
+	 * @return TStyle the style for tbody element, if any
+	 * @since 3.1.1
+	 */
+	public function getTableBodyStyle()
+	{
+		if(($style=$this->getViewState('TableBodyStyle',null))===null)
+		{
+			$style=new TStyle;
+			$this->setViewState('TableBodyStyle',$style,null);
+		}
+		return $style;
+	}
+
+	/**
+	 * @return TStyle the style for tfoot element, if any
+	 * @since 3.1.1
+	 */
+	public function getTableFootStyle()
+	{
+		if(($style=$this->getViewState('TableFootStyle',null))===null)
+		{
+			$style=new TStyle;
+			$this->setViewState('TableFootStyle',$style,null);
+		}
+		return $style;
+	}
+
+	/**
+	 * @return string caption for the datagrid
+	 */
+	public function getCaption()
+	{
+		return $this->getViewState('Caption','');
+	}
+
+	/**
+	 * @param string caption for the datagrid
+	 */
+	public function setCaption($value)
+	{
+		$this->setViewState('Caption',$value,'');
+	}
+
+	/**
+	 * @return TTableCaptionAlign datagrid caption alignment. Defaults to TTableCaptionAlign::NotSet.
+	 */
+	public function getCaptionAlign()
+	{
+		return $this->getViewState('CaptionAlign',TTableCaptionAlign::NotSet);
+	}
+
+	/**
+	 * @param TTableCaptionAlign datagrid caption alignment. Valid values include
+	 */
+	public function setCaptionAlign($value)
+	{
+		$this->setViewState('CaptionAlign',TPropertyValue::ensureEnum($value,'TTableCaptionAlign'),TTableCaptionAlign::NotSet);
+	}
+
+	/**
+	 * @return TDataGridItem the header item
+	 */
+	public function getHeader()
+	{
+		return $this->_header;
+	}
+
+	/**
+	 * @return TDataGridItem the footer item
+	 */
+	public function getFooter()
+	{
+		return $this->_footer;
+	}
+
+	/**
+	 * @return TDataGridPager the pager displayed at the top of datagrid. It could be null if paging is disabled.
+	 */
+	public function getTopPager()
+	{
+		return $this->_topPager;
+	}
+
+	/**
+	 * @return TDataGridPager the pager displayed at the bottom of datagrid. It could be null if paging is disabled.
+	 */
+	public function getBottomPager()
+	{
+		return $this->_bottomPager;
+	}
+
+	/**
+	 * @return TDataGridItem the selected item, null if no item is selected.
+	 */
+	public function getSelectedItem()
+	{
+		$index=$this->getSelectedItemIndex();
+		$items=$this->getItems();
+		if($index>=0 && $index<$items->getCount())
+			return $items->itemAt($index);
+		else
+			return null;
+	}
+
+	/**
+	 * @return integer the zero-based index of the selected item in {@link getItems Items}.
+	 * A value -1 means no item selected.
+	 */
+	public function getSelectedItemIndex()
+	{
+		return $this->getViewState('SelectedItemIndex',-1);
+	}
+
+	/**
+	 * Selects an item by its index in {@link getItems Items}.
+	 * Previously selected item will be un-selected.
+	 * If the item to be selected is already in edit mode, it will remain in edit mode.
+	 * If the index is less than 0, any existing selection will be cleared up.
+	 * @param integer the selected item index
+	 */
+	public function setSelectedItemIndex($value)
+	{
+		if(($value=TPropertyValue::ensureInteger($value))<0)
+			$value=-1;
+		if(($current=$this->getSelectedItemIndex())!==$value)
+		{
+			$this->setViewState('SelectedItemIndex',$value,-1);
+			$items=$this->getItems();
+			$itemCount=$items->getCount();
+			if($current>=0 && $current<$itemCount)
+			{
+				$item=$items->itemAt($current);
+				if($item->getItemType()!==TListItemType::EditItem)
+					$item->setItemType($current%2?TListItemType::AlternatingItem:TListItemType::Item);
+			}
+			if($value>=0 && $value<$itemCount)
+			{
+				$item=$items->itemAt($value);
+				if($item->getItemType()!==TListItemType::EditItem)
+					$item->setItemType(TListItemType::SelectedItem);
+			}
+		}
+	}
+
+	/**
+	 * @return TDataGridItem the edit item
+	 */
+	public function getEditItem()
+	{
+		$index=$this->getEditItemIndex();
+		$items=$this->getItems();
+		if($index>=0 && $index<$items->getCount())
+			return $items->itemAt($index);
+		else
+			return null;
+	}
+
+	/**
+	 * @return integer the zero-based index of the edit item in {@link getItems Items}.
+	 * A value -1 means no item is in edit mode.
+	 */
+	public function getEditItemIndex()
+	{
+		return $this->getViewState('EditItemIndex',-1);
+	}
+
+	/**
+	 * Edits an item by its index in {@link getItems Items}.
+	 * Previously editting item will change to normal item state.
+	 * If the index is less than 0, any existing edit item will be cleared up.
+	 * @param integer the edit item index
+	 */
+	public function setEditItemIndex($value)
+	{
+		if(($value=TPropertyValue::ensureInteger($value))<0)
+			$value=-1;
+		if(($current=$this->getEditItemIndex())!==$value)
+		{
+			$this->setViewState('EditItemIndex',$value,-1);
+			$items=$this->getItems();
+			$itemCount=$items->getCount();
+			if($current>=0 && $current<$itemCount)
+				$items->itemAt($current)->setItemType($current%2?TListItemType::AlternatingItem:TListItemType::Item);
+			if($value>=0 && $value<$itemCount)
+				$items->itemAt($value)->setItemType(TListItemType::EditItem);
+		}
+	}
+
+	/**
+	 * @return boolean whether sorting is enabled. Defaults to false.
+	 */
+	public function getAllowSorting()
+	{
+		return $this->getViewState('AllowSorting',false);
+	}
+
+	/**
+	 * @param boolean whether sorting is enabled
+	 */
+	public function setAllowSorting($value)
+	{
+		$this->setViewState('AllowSorting',TPropertyValue::ensureBoolean($value),false);
+	}
+
+	/**
+	 * @return boolean whether datagrid columns should be automatically generated. Defaults to true.
+	 */
+	public function getAutoGenerateColumns()
+	{
+		return $this->getViewState('AutoGenerateColumns',true);
+	}
+
+	/**
+	 * @param boolean whether datagrid columns should be automatically generated
+	 */
+	public function setAutoGenerateColumns($value)
+	{
+		$this->setViewState('AutoGenerateColumns',TPropertyValue::ensureBoolean($value),true);
+	}
+
+	/**
+	 * @return boolean whether the header should be displayed. Defaults to true.
+	 */
+	public function getShowHeader()
+	{
+		return $this->getViewState('ShowHeader',true);
+	}
+
+	/**
+	 * @param boolean whether the header should be displayed
+	 */
+	public function setShowHeader($value)
+	{
+		$this->setViewState('ShowHeader',TPropertyValue::ensureBoolean($value),true);
+	}
+
+	/**
+	 * @return boolean whether the footer should be displayed. Defaults to false.
+	 */
+	public function getShowFooter()
+	{
+		return $this->getViewState('ShowFooter',false);
+	}
+
+	/**
+	 * @param boolean whether the footer should be displayed
+	 */
+	public function setShowFooter($value)
+	{
+		$this->setViewState('ShowFooter',TPropertyValue::ensureBoolean($value),false);
+	}
+
+	/**
+	 * @return ITemplate the template applied when no data is bound to the datagrid
+	 */
+	public function getEmptyTemplate()
+	{
+		return $this->_emptyTemplate;
+	}
+
+	/**
+	 * @param ITemplate the template applied when no data is bound to the datagrid
+	 * @throws TInvalidDataTypeException if the input is not an {@link ITemplate} or not null.
+	 */
+	public function setEmptyTemplate($value)
+	{
+		if($value instanceof ITemplate || $value===null)
+			$this->_emptyTemplate=$value;
+		else
+			throw new TInvalidDataTypeException('datagrid_template_required','EmptyTemplate');
+	}
+
+	/**
+	 * This method overrides parent's implementation to handle
+	 * {@link onItemCommand OnItemCommand} event which is bubbled from
+	 * {@link TDataGridItem} child controls.
+	 * If the event parameter is {@link TDataGridCommandEventParameter} and
+	 * the command name is a recognized one, which includes 'select', 'edit',
+	 * 'delete', 'update', and 'cancel' (case-insensitive), then a
+	 * corresponding command event is also raised (such as {@link onEditCommand OnEditCommand}).
+	 * This method should only be used by control developers.
+	 * @param TControl the sender of the event
+	 * @param TEventParameter event parameter
+	 * @return boolean whether the event bubbling should stop here.
+	 */
+	public function bubbleEvent($sender,$param)
+	{
+		if($param instanceof TDataGridCommandEventParameter)
+		{
+			$this->onItemCommand($param);
+			$command=$param->getCommandName();
+			if(strcasecmp($command,self::CMD_SELECT)===0)
+			{
+				$this->setSelectedItemIndex($param->getItem()->getItemIndex());
+				$this->onSelectedIndexChanged($param);
+				return true;
+			}
+			else if(strcasecmp($command,self::CMD_EDIT)===0)
+			{
+				$this->onEditCommand($param);
+				return true;
+			}
+			else if(strcasecmp($command,self::CMD_DELETE)===0)
+			{
+				$this->onDeleteCommand($param);
+				return true;
+			}
+			else if(strcasecmp($command,self::CMD_UPDATE)===0)
+			{
+				$this->onUpdateCommand($param);
+				return true;
+			}
+			else if(strcasecmp($command,self::CMD_CANCEL)===0)
+			{
+				$this->onCancelCommand($param);
+				return true;
+			}
+			else if(strcasecmp($command,self::CMD_SORT)===0)
+			{
+				$this->onSortCommand(new TDataGridSortCommandEventParameter($sender,$param));
+				return true;
+			}
+			else if(strcasecmp($command,self::CMD_PAGE)===0)
+			{
+				$p=$param->getCommandParameter();
+				if(strcasecmp($p,self::CMD_PAGE_NEXT)===0)
+					$pageIndex=$this->getCurrentPageIndex()+1;
+				else if(strcasecmp($p,self::CMD_PAGE_PREV)===0)
+					$pageIndex=$this->getCurrentPageIndex()-1;
+				else if(strcasecmp($p,self::CMD_PAGE_FIRST)===0)
+					$pageIndex=0;
+				else if(strcasecmp($p,self::CMD_PAGE_LAST)===0)
+					$pageIndex=$this->getPageCount()-1;
+				else
+					$pageIndex=TPropertyValue::ensureInteger($p)-1;
+				$this->onPageIndexChanged(new TDataGridPageChangedEventParameter($sender,$pageIndex));
+				return true;
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * Raises <b>OnCancelCommand</b> event.
+	 * This method is invoked when a button control raises <b>OnCommand</b> event
+	 * with <b>cancel</b> command name.
+	 * @param TDataGridCommandEventParameter event parameter
+	 */
+	public function onCancelCommand($param)
+	{
+		$this->raiseEvent('OnCancelCommand',$this,$param);
+	}
+
+	/**
+	 * Raises <b>OnDeleteCommand</b> event.
+	 * This method is invoked when a button control raises <b>OnCommand</b> event
+	 * with <b>delete</b> command name.
+	 * @param TDataGridCommandEventParameter event parameter
+	 */
+	public function onDeleteCommand($param)
+	{
+		$this->raiseEvent('OnDeleteCommand',$this,$param);
+	}
+
+	/**
+	 * Raises <b>OnEditCommand</b> event.
+	 * This method is invoked when a button control raises <b>OnCommand</b> event
+	 * with <b>edit</b> command name.
+	 * @param TDataGridCommandEventParameter event parameter
+	 */
+	public function onEditCommand($param)
+	{
+		$this->raiseEvent('OnEditCommand',$this,$param);
+	}
+
+	/**
+	 * Raises <b>OnItemCommand</b> event.
+	 * This method is invoked when a button control raises <b>OnCommand</b> event.
+	 * @param TDataGridCommandEventParameter event parameter
+	 */
+	public function onItemCommand($param)
+	{
+		$this->raiseEvent('OnItemCommand',$this,$param);
+	}
+
+	/**
+	 * Raises <b>OnSortCommand</b> event.
+	 * This method is invoked when a button control raises <b>OnCommand</b> event
+	 * with <b>sort</b> command name.
+	 * @param TDataGridSortCommandEventParameter event parameter
+	 */
+	public function onSortCommand($param)
+	{
+		$this->raiseEvent('OnSortCommand',$this,$param);
+	}
+
+	/**
+	 * Raises <b>OnUpdateCommand</b> event.
+	 * This method is invoked when a button control raises <b>OnCommand</b> event
+	 * with <b>update</b> command name.
+	 * @param TDataGridCommandEventParameter event parameter
+	 */
+	public function onUpdateCommand($param)
+	{
+		$this->raiseEvent('OnUpdateCommand',$this,$param);
+	}
+
+	/**
+	 * Raises <b>OnItemCreated</b> event.
+	 * This method is invoked right after a datagrid item is created and before
+	 * added to page hierarchy.
+	 * @param TDataGridItemEventParameter event parameter
+	 */
+	public function onItemCreated($param)
+	{
+		$this->raiseEvent('OnItemCreated',$this,$param);
+	}
+
+	/**
+	 * Raises <b>OnPagerCreated</b> event.
+	 * This method is invoked right after a datagrid pager is created and before
+	 * added to page hierarchy.
+	 * @param TDataGridPagerEventParameter event parameter
+	 */
+	public function onPagerCreated($param)
+	{
+		$this->raiseEvent('OnPagerCreated',$this,$param);
+	}
+
+	/**
+	 * Raises <b>OnItemDataBound</b> event.
+	 * This method is invoked for each datagrid item after it performs
+	 * databinding.
+	 * @param TDataGridItemEventParameter event parameter
+	 */
+	public function onItemDataBound($param)
+	{
+		$this->raiseEvent('OnItemDataBound',$this,$param);
+	}
+
+	/**
+	 * Raises <b>OnPageIndexChanged</b> event.
+	 * This method is invoked when current page is changed.
+	 * @param TDataGridPageChangedEventParameter event parameter
+	 */
+	public function onPageIndexChanged($param)
+	{
+		$this->raiseEvent('OnPageIndexChanged',$this,$param);
+	}
+
+	/**
+	 * Saves item count in viewstate.
+	 * This method is invoked right before control state is to be saved.
+	 */
+	public function saveState()
+	{
+		parent::saveState();
+		if(!$this->getEnableViewState(true))
+			return;
+		if($this->_items)
+			$this->setViewState('ItemCount',$this->_items->getCount(),0);
+		else
+			$this->clearViewState('ItemCount');
+		if($this->_autoColumns)
+		{
+			$state=array();
+			foreach($this->_autoColumns as $column)
+				$state[]=$column->saveState();
+			$this->setViewState('AutoColumns',$state,array());
+		}
+		else
+			$this->clearViewState('AutoColumns');
+		if($this->_columns)
+		{
+			$state=array();
+			foreach($this->_columns as $column)
+				$state[]=$column->saveState();
+			$this->setViewState('Columns',$state,array());
+		}
+		else
+			$this->clearViewState('Columns');
+	}
+
+	/**
+	 * Loads item count information from viewstate.
+	 * This method is invoked right after control state is loaded.
+	 */
+	public function loadState()
+	{
+		parent::loadState();
+		if(!$this->getEnableViewState(true))
+			return;
+		if(!$this->getIsDataBound())
+		{
+			$state=$this->getViewState('AutoColumns',array());
+			if(!empty($state))
+			{
+				$this->_autoColumns=new TDataGridColumnCollection($this);
+				foreach($state as $st)
+				{
+					$column=new $this->AutoGenerateColumnName;
+					$column->loadState($st);
+					$this->_autoColumns->add($column);
+				}
+			}
+			else
+				$this->_autoColumns=null;
+			$state=$this->getViewState('Columns',array());
+			if($this->_columns && $this->_columns->getCount()===count($state))
+			{
+				$i=0;
+				foreach($this->_columns as $column)
+				{
+					$column->loadState($state[$i]);
+					$i++;
+				}
+			}
+			$this->restoreGridFromViewState();
+		}
+	}
+
+	/**
+	 * Clears up all items in the datagrid.
+	 */
+	public function reset()
+	{
+		$this->getControls()->clear();
+		$this->getItems()->clear();
+		$this->_header=null;
+		$this->_footer=null;
+		$this->_topPager=null;
+		$this->_bottomPager=null;
+		$this->_useEmptyTemplate=false;
+	}
+
+	/**
+	 * Restores datagrid content from viewstate.
+	 */
+	protected function restoreGridFromViewState()
+	{
+		$this->reset();
+
+		$allowPaging=$this->getAllowPaging();
+
+		$itemCount=$this->getViewState('ItemCount',0);
+		$dsIndex=$this->getViewState('DataSourceIndex',0);
+
+		$columns=new TList($this->getColumns());
+		$columns->mergeWith($this->_autoColumns);
+		$this->_allColumns=$columns;
+
+		$items=$this->getItems();
+
+		if($columns->getCount())
+		{
+			foreach($columns as $column)
+				$column->initialize();
+			$selectedIndex=$this->getSelectedItemIndex();
+			$editIndex=$this->getEditItemIndex();
+			for($index=0;$index<$itemCount;++$index)
+			{
+				if($index===0)
+				{
+					if($allowPaging)
+						$this->_topPager=$this->createPager();
+					$this->_header=$this->createItemInternal(-1,-1,TListItemType::Header,false,null,$columns);
+				}
+				if($index===$editIndex)
+					$itemType=TListItemType::EditItem;
+				else if($index===$selectedIndex)
+					$itemType=TListItemType::SelectedItem;
+				else if($index % 2)
+					$itemType=TListItemType::AlternatingItem;
+				else
+					$itemType=TListItemType::Item;
+				$items->add($this->createItemInternal($index,$dsIndex,$itemType,false,null,$columns));
+				$dsIndex++;
+			}
+			if($index>0)
+			{
+				$this->_footer=$this->createItemInternal(-1,-1,TListItemType::Footer,false,null,$columns);
+				if($allowPaging)
+					$this->_bottomPager=$this->createPager();
+			}
+		}
+		if(!$dsIndex && $this->_emptyTemplate!==null)
+		{
+			$this->_useEmptyTemplate=true;
+			$this->_emptyTemplate->instantiateIn($this);
+		}
+	}
+
+	/**
+	 * Performs databinding to populate datagrid items from data source.
+	 * This method is invoked by {@link dataBind()}.
+	 * You may override this function to provide your own way of data population.
+	 * @param Traversable the bound data
+	 */
+	protected function performDataBinding($data)
+	{
+		$this->reset();
+		$keys=$this->getDataKeys();
+		$keys->clear();
+		$keyField=$this->getDataKeyField();
+
+		// get all columns
+		if($this->getAutoGenerateColumns())
+		{
+			$columns=new TList($this->getColumns());
+			$autoColumns=$this->createAutoColumns($data);
+			$columns->mergeWith($autoColumns);
+		}
+		else
+			$columns=$this->getColumns();
+		$this->_allColumns=$columns;
+
+		$items=$this->getItems();
+
+		$index=0;
+		$allowPaging=$this->getAllowPaging() && ($data instanceof TPagedDataSource);
+		$dsIndex=$allowPaging?$data->getFirstIndexInPage():0;
+		$this->setViewState('DataSourceIndex',$dsIndex,0);
+		if($columns->getCount())
+		{
+			foreach($columns as $column)
+				$column->initialize();
+
+			$selectedIndex=$this->getSelectedItemIndex();
+			$editIndex=$this->getEditItemIndex();
+			foreach($data as $key=>$row)
+			{
+				if($keyField!=='')
+					$keys->add($this->getDataFieldValue($row,$keyField));
+				else
+					$keys->add($key);
+				if($index===0)
+				{
+					if($allowPaging)
+						$this->_topPager=$this->createPager();
+					$this->_header=$this->createItemInternal(-1,-1,TListItemType::Header,true,null,$columns);
+				}
+				if($index===$editIndex)
+					$itemType=TListItemType::EditItem;
+				else if($index===$selectedIndex)
+					$itemType=TListItemType::SelectedItem;
+				else if($index % 2)
+					$itemType=TListItemType::AlternatingItem;
+				else
+					$itemType=TListItemType::Item;
+				$items->add($this->createItemInternal($index,$dsIndex,$itemType,true,$row,$columns));
+				$index++;
+				$dsIndex++;
+			}
+			if($index>0)
+			{
+				$this->_footer=$this->createItemInternal(-1,-1,TListItemType::Footer,true,null,$columns);
+				if($allowPaging)
+					$this->_bottomPager=$this->createPager();
+			}
+		}
+		$this->setViewState('ItemCount',$index,0);
+		if(!$dsIndex && $this->_emptyTemplate!==null)
+		{
+			$this->_useEmptyTemplate=true;
+			$this->_emptyTemplate->instantiateIn($this);
+			$this->dataBindChildren();
+		}
+	}
+
+	/**
+	 * Merges consecutive cells who have the same text.
+	 * @since 3.1.1
+	 */
+	private function groupCells()
+	{
+		if(($columns=$this->_allColumns)===null)
+			return;
+		$items=$this->getItems();
+		foreach($columns as $id=>$column)
+		{
+			if(!$column->getEnableCellGrouping())
+				continue;
+			$prevCell=null;
+			$prevCellText=null;
+			foreach($items as $item)
+			{
+				$itemType=$item->getItemType();
+				$cell=$item->getCells()->itemAt($id);
+				if(!$cell->getVisible())
+					continue;
+				if($itemType===TListItemType::Item || $itemType===TListItemType::AlternatingItem || $itemType===TListItemType::SelectedItem)
+				{
+					if(($cellText=$this->getCellText($cell))==='')
+					{
+						$prevCell=null;
+						$prevCellText=null;
+						continue;
+					}
+					if($prevCell===null || $prevCellText!==$cellText)
+					{
+						$prevCell=$cell;
+						$prevCellText=$cellText;
+					}
+					else
+					{
+						if(($rowSpan=$prevCell->getRowSpan())===0)
+							$rowSpan=1;
+						$prevCell->setRowSpan($rowSpan+1);
+						$cell->setVisible(false);
+					}
+				}
+			}
+		}
+	}
+
+	private function getCellText($cell)
+	{
+		if(($data=$cell->getText())==='' && $cell->getHasControls())
+		{
+			$controls=$cell->getControls();
+			foreach($controls as $control)
+			{
+				if($control instanceof IDataRenderer)
+					return $control->getData();
+			}
+		}
+		return $data;
+	}
+
+	/**
+	 * Creates a datagrid item instance based on the item type and index.
+	 * @param integer zero-based item index
+	 * @param TListItemType item type
+	 * @return TDataGridItem created data list item
+	 */
+	protected function createItem($itemIndex,$dataSourceIndex,$itemType)
+	{
+		return new TDataGridItem($itemIndex,$dataSourceIndex,$itemType);
+	}
+
+	private function createItemInternal($itemIndex,$dataSourceIndex,$itemType,$dataBind,$dataItem,$columns)
+	{
+		$item=$this->createItem($itemIndex,$dataSourceIndex,$itemType);
+		$this->initializeItem($item,$columns);
+		$param=new TDataGridItemEventParameter($item);
+		if($dataBind)
+		{
+			$item->setDataItem($dataItem);
+			$this->onItemCreated($param);
+			$this->getControls()->add($item);
+			$item->dataBind();
+			$this->onItemDataBound($param);
+		}
+		else
+		{
+			$this->onItemCreated($param);
+			$this->getControls()->add($item);
+		}
+		return $item;
+	}
+
+	/**
+	 * Initializes a datagrid item and cells inside it
+	 * @param TDataGrid datagrid item to be initialized
+	 * @param TDataGridColumnCollection datagrid columns to be used to initialize the cells in the item
+	 */
+	protected function initializeItem($item,$columns)
+	{
+		$cells=$item->getCells();
+		$itemType=$item->getItemType();
+		$index=0;
+		foreach($columns as $column)
+		{
+			if($itemType===TListItemType::Header)
+				$cell=new TTableHeaderCell;
+			else
+				$cell=new TTableCell;
+			if(($id=$column->getID())!=='')
+				$item->registerObject($id,$cell);
+			$cells->add($cell);
+			$column->initializeCell($cell,$index,$itemType);
+			$index++;
+		}
+	}
+
+	protected function createPager()
+	{
+		$pager=new TDataGridPager($this);
+		$this->buildPager($pager);
+		$this->onPagerCreated(new TDataGridPagerEventParameter($pager));
+		$this->getControls()->add($pager);
+		return $pager;
+	}
+
+	/**
+	 * Builds the pager content based on pager style.
+	 * @param TDataGridPager the container for the pager
+	 */
+	protected function buildPager($pager)
+	{
+		switch($this->getPagerStyle()->getMode())
+		{
+			case TDataGridPagerMode::NextPrev:
+				$this->buildNextPrevPager($pager);
+				break;
+			case TDataGridPagerMode::Numeric:
+				$this->buildNumericPager($pager);
+				break;
+		}
+	}
+
+	/**
+	 * Creates a pager button.
+	 * Depending on the button type, a TLinkButton or a TButton may be created.
+	 * If it is enabled (clickable), its command name and parameter will also be set.
+	 * Derived classes may override this method to create additional types of buttons, such as TImageButton.
+	 * @param mixed the container pager instance of TActiveDatagridPager 
+	 * @param string button type, either LinkButton or PushButton
+	 * @param boolean whether the button should be enabled
+	 * @param string caption of the button
+	 * @param string CommandName corresponding to the OnCommand event of the button
+	 * @param string CommandParameter corresponding to the OnCommand event of the button
+	 * @return mixed the button instance
+	 */
+	protected function createPagerButton($pager,$buttonType,$enabled,$text,$commandName,$commandParameter)
+	{
+		if($buttonType===TDataGridPagerButtonType::LinkButton)
+		{
+			if($enabled)
+				$button=new TLinkButton;
+			else
+			{
+				$button=new TLabel;
+				$button->setText($text);
+				return $button;
+			}
+		}
+		else
+		{
+			$button=new TButton;
+			if(!$enabled)
+				$button->setEnabled(false);
+		}
+		$button->setText($text);
+		$button->setCommandName($commandName);
+		$button->setCommandParameter($commandParameter);
+		$button->setCausesValidation(false);
+		return $button;
+	}
+
+	/**
+	 * Builds a next-prev pager
+	 * @param TDataGridPager the container for the pager
+	 */
+	protected function buildNextPrevPager($pager)
+	{
+		$style=$this->getPagerStyle();
+		$buttonType=$style->getButtonType();
+		$controls=$pager->getControls();
+		$currentPageIndex=$this->getCurrentPageIndex();
+		if($currentPageIndex===0)
+		{
+			if(($text=$style->getFirstPageText())!=='')
+			{
+				$label=$this->createPagerButton($pager,$buttonType,false,$text,'','');
+				$controls->add($label);
+				$controls->add("\n");
+			}
+
+			$label=$this->createPagerButton($pager,$buttonType,false,$style->getPrevPageText(),'','');
+			$controls->add($label);
+		}
+		else
+		{
+			if(($text=$style->getFirstPageText())!=='')
+			{
+				$button=$this->createPagerButton($pager,$buttonType,true,$text,self::CMD_PAGE,self::CMD_PAGE_FIRST);
+				$controls->add($button);
+				$controls->add("\n");
+			}
+
+			$button=$this->createPagerButton($pager,$buttonType,true,$style->getPrevPageText(),self::CMD_PAGE,self::CMD_PAGE_PREV);
+			$controls->add($button);
+		}
+		$controls->add("\n");
+		if($currentPageIndex===$this->getPageCount()-1)
+		{
+			$label=$this->createPagerButton($pager,$buttonType,false,$style->getNextPageText(),'','');
+			$controls->add($label);
+			if(($text=$style->getLastPageText())!=='')
+			{
+				$controls->add("\n");
+				$label=$this->createPagerButton($pager,$buttonType,false,$text,'','');
+				$controls->add($label);
+			}
+		}
+		else
+		{
+			$button=$this->createPagerButton($pager,$buttonType,true,$style->getNextPageText(),self::CMD_PAGE,self::CMD_PAGE_NEXT);
+			$controls->add($button);
+			if(($text=$style->getLastPageText())!=='')
+			{
+				$controls->add("\n");
+				$button=$this->createPagerButton($pager,$buttonType,true,$text,self::CMD_PAGE,self::CMD_PAGE_LAST);
+				$controls->add($button);
+			}
+		}
+	}
+
+	/**
+	 * Builds a numeric pager
+	 * @param TDataGridPager the container for the pager
+	 */
+	protected function buildNumericPager($pager)
+	{
+		$style=$this->getPagerStyle();
+		$buttonType=$style->getButtonType();
+		$controls=$pager->getControls();
+		$pageCount=$this->getPageCount();
+		$pageIndex=$this->getCurrentPageIndex()+1;
+		$maxButtonCount=$style->getPageButtonCount();
+		$buttonCount=$maxButtonCount>$pageCount?$pageCount:$maxButtonCount;
+		$startPageIndex=1;
+		$endPageIndex=$buttonCount;
+		if($pageIndex>$endPageIndex)
+		{
+			$startPageIndex=((int)(($pageIndex-1)/$maxButtonCount))*$maxButtonCount+1;
+			if(($endPageIndex=$startPageIndex+$maxButtonCount-1)>$pageCount)
+				$endPageIndex=$pageCount;
+			if($endPageIndex-$startPageIndex+1<$maxButtonCount)
+			{
+				if(($startPageIndex=$endPageIndex-$maxButtonCount+1)<1)
+					$startPageIndex=1;
+			}
+		}
+
+		if($startPageIndex>1)
+		{
+			if(($text=$style->getFirstPageText())!=='')
+			{
+				$button=$this->createPagerButton($pager,$buttonType,true,$text,self::CMD_PAGE,self::CMD_PAGE_FIRST);
+				$controls->add($button);
+				$controls->add("\n");
+			}
+			$prevPageIndex=$startPageIndex-1;
+			$button=$this->createPagerButton($pager,$buttonType,true,$style->getPrevPageText(),self::CMD_PAGE,"$prevPageIndex");
+			$controls->add($button);
+			$controls->add("\n");
+		}
+
+		for($i=$startPageIndex;$i<=$endPageIndex;++$i)
+		{
+			if($i===$pageIndex)
+			{
+				$label=$this->createPagerButton($pager,$buttonType,false,"$i",'','');
+				$controls->add($label);
+			}
+			else
+			{
+				$button=$this->createPagerButton($pager,$buttonType,true,"$i",self::CMD_PAGE,"$i");
+				$controls->add($button);
+			}
+			if($i<$endPageIndex)
+				$controls->add("\n");
+		}
+
+		if($pageCount>$endPageIndex)
+		{
+			$controls->add("\n");
+			$nextPageIndex=$endPageIndex+1;
+			$button=$this->createPagerButton($pager,$buttonType,true,$style->getNextPageText(),self::CMD_PAGE,"$nextPageIndex");
+			$controls->add($button);
+			if(($text=$style->getLastPageText())!=='')
+			{
+				$controls->add("\n");
+				$button=$this->createPagerButton($pager,$buttonType,true,$text,self::CMD_PAGE,self::CMD_PAGE_LAST);
+				$controls->add($button);
+			}
+		}
+	}
+
+	/**
+	 * Automatically generates datagrid columns based on datasource schema
+	 * @param Traversable data source bound to the datagrid
+	 * @return TDataGridColumnCollection
+	 */
+	protected function createAutoColumns($dataSource)
+	{
+		if(!$dataSource)
+			return null;
+		$autoColumns=$this->getAutoColumns();
+		$autoColumns->clear();
+		foreach($dataSource as $row)
+		{
+			foreach($row as $key=>$value)
+			{
+				$column=new $this->AutoGenerateColumnName;
+				if(is_string($key))
+				{
+					$column->setHeaderText($key);
+					$column->setDataField($key);
+					$column->setSortExpression($key);
+					$autoColumns->add($column);
+				}
+				else
+				{
+					$column->setHeaderText(TListItemType::Item);
+					$column->setDataField($key);
+					$column->setSortExpression(TListItemType::Item);
+					$autoColumns->add($column);
+				}
+			}
+			break;
+		}
+		return $autoColumns;
+	}
+
+	/**
+	 * Applies styles to items, header, footer and separators.
+	 * Item styles are applied in a hierarchical way. Style in higher hierarchy
+	 * will inherit from styles in lower hierarchy.
+	 * Starting from the lowest hierarchy, the item styles include
+	 * item's own style, {@link getItemStyle ItemStyle}, {@link getAlternatingItemStyle AlternatingItemStyle},
+	 * {@link getSelectedItemStyle SelectedItemStyle}, and {@link getEditItemStyle EditItemStyle}.
+	 * Therefore, if background color is set as red in {@link getItemStyle ItemStyle},
+	 * {@link getEditItemStyle EditItemStyle} will also have red background color
+	 * unless it is set to a different value explicitly.
+	 */
+	protected function applyItemStyles()
+	{
+		$itemStyle=$this->getViewState('ItemStyle',null);
+
+		$alternatingItemStyle=$this->getViewState('AlternatingItemStyle',null);
+		if($itemStyle!==null)
+		{
+			if($alternatingItemStyle===null)
+				$alternatingItemStyle=$itemStyle;
+			else
+				$alternatingItemStyle->mergeWith($itemStyle);
+		}
+
+		$selectedItemStyle=$this->getViewState('SelectedItemStyle',null);
+
+		$editItemStyle=$this->getViewState('EditItemStyle',null);
+		if($selectedItemStyle!==null)
+		{
+			if($editItemStyle===null)
+				$editItemStyle=$selectedItemStyle;
+			else
+				$editItemStyle->mergeWith($selectedItemStyle);
+		}
+
+		$headerStyle=$this->getViewState('HeaderStyle',null);
+		$footerStyle=$this->getViewState('FooterStyle',null);
+		$pagerStyle=$this->getViewState('PagerStyle',null);
+		$separatorStyle=$this->getViewState('SeparatorStyle',null);
+
+		foreach($this->getControls() as $index=>$item)
+		{
+			if(!($item instanceof TDataGridItem) && !($item instanceof TDataGridPager))
+				continue;
+			$itemType=$item->getItemType();
+			switch($itemType)
+			{
+				case TListItemType::Header:
+					if($headerStyle)
+						$item->getStyle()->mergeWith($headerStyle);
+					if(!$this->getShowHeader())
+						$item->setVisible(false);
+					break;
+				case TListItemType::Footer:
+					if($footerStyle)
+						$item->getStyle()->mergeWith($footerStyle);
+					if(!$this->getShowFooter())
+						$item->setVisible(false);
+					break;
+				case TListItemType::Separator:
+					if($separatorStyle)
+						$item->getStyle()->mergeWith($separatorStyle);
+					break;
+				case TListItemType::Item:
+					if($itemStyle)
+						$item->getStyle()->mergeWith($itemStyle);
+					break;
+				case TListItemType::AlternatingItem:
+					if($alternatingItemStyle)
+						$item->getStyle()->mergeWith($alternatingItemStyle);
+					break;
+				case TListItemType::SelectedItem:
+					if($selectedItemStyle)
+						$item->getStyle()->mergeWith($selectedItemStyle);
+					if($index % 2==1)
+					{
+						if($itemStyle)
+							$item->getStyle()->mergeWith($itemStyle);
+					}
+					else
+					{
+						if($alternatingItemStyle)
+							$item->getStyle()->mergeWith($alternatingItemStyle);
+					}
+					break;
+				case TListItemType::EditItem:
+					if($editItemStyle)
+						$item->getStyle()->mergeWith($editItemStyle);
+					if($index % 2==1)
+					{
+						if($itemStyle)
+							$item->getStyle()->mergeWith($itemStyle);
+					}
+					else
+					{
+						if($alternatingItemStyle)
+							$item->getStyle()->mergeWith($alternatingItemStyle);
+					}
+					break;
+				case TListItemType::Pager:
+					if($pagerStyle)
+					{
+						$item->getStyle()->mergeWith($pagerStyle);
+						if($index===0)
+						{
+							if($pagerStyle->getPosition()===TDataGridPagerPosition::Bottom || !$pagerStyle->getVisible())
+								$item->setVisible(false);
+						}
+						else
+						{
+							if($pagerStyle->getPosition()===TDataGridPagerPosition::Top || !$pagerStyle->getVisible())
+								$item->setVisible(false);
+						}
+					}
+					break;
+				default:
+					break;
+			}
+			if($this->_columns && $itemType!==TListItemType::Pager)
+			{
+				$n=$this->_columns->getCount();
+				$cells=$item->getCells();
+				for($i=0;$i<$n;++$i)
+				{
+					$cell=$cells->itemAt($i);
+					$column=$this->_columns->itemAt($i);
+					if(!$column->getVisible())
+						$cell->setVisible(false);
+					else
+					{
+						if($itemType===TListItemType::Header)
+							$style=$column->getHeaderStyle(false);
+						else if($itemType===TListItemType::Footer)
+							$style=$column->getFooterStyle(false);
+						else
+							$style=$column->getItemStyle(false);
+						if($style!==null)
+							$cell->getStyle()->mergeWith($style);
+					}
+				}
+			}
+		}
+	}
+
+	/**
+	 * Renders the openning tag for the datagrid control which will render table caption if present.
+	 * @param THtmlWriter the writer used for the rendering purpose
+	 */
+	public function renderBeginTag($writer)
+	{
+		parent::renderBeginTag($writer);
+		if(($caption=$this->getCaption())!=='')
+		{
+			if(($align=$this->getCaptionAlign())!==TTableCaptionAlign::NotSet)
+				$writer->addAttribute('align',strtolower($align));
+			$writer->renderBeginTag('caption');
+			$writer->write($caption);
+			$writer->renderEndTag();
+		}
+	}
+
+	/**
+	 * Renders the datagrid.
+	 * @param THtmlWriter writer for the rendering purpose
+	 */
+	public function render($writer)
+	{
+		if($this->getHasControls())
+		{
+			$this->groupCells();
+			if($this->_useEmptyTemplate)
+			{
+				$control=new TWebControl;
+				$control->setID($this->getClientID());
+				$control->copyBaseAttributes($this);
+				if($this->getHasStyle())
+					$control->getStyle()->copyFrom($this->getStyle());
+				$control->renderBeginTag($writer);
+				$this->renderContents($writer);
+				$control->renderEndTag($writer);
+			}
+			else if($this->getViewState('ItemCount',0)>0)
+			{
+				$this->applyItemStyles();
+				if($this->_topPager)
+				{
+					$this->_topPager->renderControl($writer);
+					$writer->writeLine();
+				}
+				$this->renderTable($writer);
+				if($this->_bottomPager)
+				{
+					$writer->writeLine();
+					$this->_bottomPager->renderControl($writer);
+				}
+			}
+		}
+	}
+
+	/**
+	 * Renders the tabular data.
+	 * @param THtmlWriter writer
+	 */
+	protected function renderTable($writer)
+	{
+		$this->renderBeginTag($writer);
+		if($this->_header && $this->_header->getVisible())
+		{
+			$writer->writeLine();
+			if($style=$this->getViewState('TableHeadStyle',null))
+				$style->addAttributesToRender($writer);
+			$writer->renderBeginTag('thead');
+			$this->_header->render($writer);
+			$writer->renderEndTag();
+		}
+		$writer->writeLine();
+		if($style=$this->getViewState('TableBodyStyle',null))
+			$style->addAttributesToRender($writer);
+		$writer->renderBeginTag('tbody');
+		foreach($this->getItems() as $item)
+			$item->renderControl($writer);
+		$writer->renderEndTag();
+
+		if($this->_footer && $this->_footer->getVisible())
+		{
+			$writer->writeLine();
+			if($style=$this->getViewState('TableFootStyle',null))
+				$style->addAttributesToRender($writer);
+			$writer->renderBeginTag('tfoot');
+			$this->_footer->render($writer);
+			$writer->renderEndTag();
+		}
+
+		$writer->writeLine();
+		$this->renderEndTag($writer);
+	}
+}
+
+/**
+ * TDataGridItemEventParameter class
+ *
+ * TDataGridItemEventParameter encapsulates the parameter data for
+ * {@link TDataGrid::onItemCreated OnItemCreated} event of {@link TDataGrid} controls.
+ * The {@link getItem Item} property indicates the datagrid item related with the event.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ * @since 3.0
+ */
+class TDataGridItemEventParameter extends TEventParameter
+{
+	/**
+	 * The TDataGridItem control responsible for the event.
+	 * @var TDataGridItem
+	 */
+	private $_item=null;
+
+	/**
+	 * Constructor.
+	 * @param TDataGridItem datagrid item related with the corresponding event
+	 */
+	public function __construct(TDataGridItem $item)
+	{
+		$this->_item=$item;
+	}
+
+	/**
+	 * @return TDataGridItem datagrid item related with the corresponding event
+	 */
+	public function getItem()
+	{
+		return $this->_item;
+	}
+}
+
+/**
+ * TDataGridPagerEventParameter class
+ *
+ * TDataGridPagerEventParameter encapsulates the parameter data for
+ * {@link TDataGrid::onPagerCreated OnPagerCreated} event of {@link TDataGrid} controls.
+ * The {@link getPager Pager} property indicates the datagrid pager related with the event.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ * @since 3.0
+ */
+class TDataGridPagerEventParameter extends TEventParameter
+{
+	/**
+	 * The TDataGridPager control responsible for the event.
+	 * @var TDataGridPager
+	 */
+	protected $_pager=null;
+
+	/**
+	 * Constructor.
+	 * @param TDataGridPager datagrid pager related with the corresponding event
+	 */
+	public function __construct(TDataGridPager $pager)
+	{
+		$this->_pager=$pager;
+	}
+
+	/**
+	 * @return TDataGridPager datagrid pager related with the corresponding event
+	 */
+	public function getPager()
+	{
+		return $this->_pager;
+	}
+}
+
+/**
+ * TDataGridCommandEventParameter class
+ *
+ * TDataGridCommandEventParameter encapsulates the parameter data for
+ * {@link TDataGrid::onItemCommand ItemCommand} event of {@link TDataGrid} controls.
+ *
+ * The {@link getItem Item} property indicates the datagrid item related with the event.
+ * The {@link getCommandSource CommandSource} refers to the control that originally
+ * raises the Command event.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ * @since 3.0
+ */
+class TDataGridCommandEventParameter extends TCommandEventParameter
+{
+	/**
+	 * @var TDataGridItem the TDataGridItem control responsible for the event.
+	 */
+	private $_item=null;
+	/**
+	 * @var TControl the control originally raises the <b>Command</b> event.
+	 */
+	private $_source=null;
+
+	/**
+	 * Constructor.
+	 * @param TDataGridItem datagrid item responsible for the event
+	 * @param TControl original event sender
+	 * @param TCommandEventParameter original event parameter
+	 */
+	public function __construct($item,$source,TCommandEventParameter $param)
+	{
+		$this->_item=$item;
+		$this->_source=$source;
+		parent::__construct($param->getCommandName(),$param->getCommandParameter());
+	}
+
+	/**
+	 * @return TDataGridItem the TDataGridItem control responsible for the event.
+	 */
+	public function getItem()
+	{
+		return $this->_item;
+	}
+
+	/**
+	 * @return TControl the control originally raises the <b>Command</b> event.
+	 */
+	public function getCommandSource()
+	{
+		return $this->_source;
+	}
+}
+
+/**
+ * TDataGridSortCommandEventParameter class
+ *
+ * TDataGridSortCommandEventParameter encapsulates the parameter data for
+ * {@link TDataGrid::onSortCommand SortCommand} event of {@link TDataGrid} controls.
+ *
+ * The {@link getCommandSource CommandSource} property refers to the control
+ * that originally raises the OnCommand event, while {@link getSortExpression SortExpression}
+ * gives the sort expression carried with the sort command.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ * @since 3.0
+ */
+class TDataGridSortCommandEventParameter extends TEventParameter
+{
+	/**
+	 * @var string sort expression
+	 */
+	private $_sortExpression='';
+	/**
+	 * @var TControl original event sender
+	 */
+	private $_source=null;
+
+	/**
+	 * Constructor.
+	 * @param TControl the control originally raises the <b>OnCommand</b> event.
+	 * @param TDataGridCommandEventParameter command event parameter
+	 */
+	public function __construct($source,TDataGridCommandEventParameter $param)
+	{
+		$this->_source=$source;
+		$this->_sortExpression=$param->getCommandParameter();
+	}
+
+	/**
+	 * @return TControl the control originally raises the <b>OnCommand</b> event.
+	 */
+	public function getCommandSource()
+	{
+		return $this->_source;
+	}
+
+	/**
+	 * @return string sort expression
+	 */
+	public function getSortExpression()
+	{
+		return $this->_sortExpression;
+	}
+}
+
+/**
+ * TDataGridPageChangedEventParameter class
+ *
+ * TDataGridPageChangedEventParameter encapsulates the parameter data for
+ * {@link TDataGrid::onPageIndexChanged PageIndexChanged} event of {@link TDataGrid} controls.
+ *
+ * The {@link getCommandSource CommandSource} property refers to the control
+ * that originally raises the OnCommand event, while {@link getNewPageIndex NewPageIndex}
+ * returns the new page index carried with the page command.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ * @since 3.0
+ */
+class TDataGridPageChangedEventParameter extends TEventParameter
+{
+	/**
+	 * @var integer new page index
+	 */
+	private $_newIndex;
+	/**
+	 * @var TControl original event sender
+	 */
+	private $_source=null;
+
+	/**
+	 * Constructor.
+	 * @param TControl the control originally raises the <b>OnCommand</b> event.
+	 * @param integer new page index
+	 */
+	public function __construct($source,$newPageIndex)
+	{
+		$this->_source=$source;
+		$this->_newIndex=$newPageIndex;
+	}
+
+	/**
+	 * @return TControl the control originally raises the <b>OnCommand</b> event.
+	 */
+	public function getCommandSource()
+	{
+		return $this->_source;
+	}
+
+	/**
+	 * @return integer new page index
+	 */
+	public function getNewPageIndex()
+	{
+		return $this->_newIndex;
+	}
+}
+
+/**
+ * TDataGridItem class
+ *
+ * A TDataGridItem control represents an item in the {@link TDataGrid} control,
+ * such as heading section, footer section, or a data item.
+ * The index and data value of the item can be accessed via {@link getItemIndex ItemIndex}>
+ * and {@link getDataItem DataItem} properties, respectively. The type of the item
+ * is given by {@link getItemType ItemType} property. Property {@link getDataSourceIndex DataSourceIndex}
+ * gives the index of the item from the bound data source.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ * @since 3.0
+ */
+class TDataGridItem extends TTableRow implements INamingContainer
+{
+	/**
+	 * @var integer index of the data item in the Items collection of datagrid
+	 */
+	private $_itemIndex='';
+	/**
+	 * @var integer index of the item from the bound data source
+	 */
+	private $_dataSourceIndex=0;
+	/**
+	 * type of the TDataGridItem
+	 * @var string
+	 */
+	private $_itemType='';
+	/**
+	 * value of the data item
+	 * @var mixed
+	 */
+	private $_data=null;
+
+	/**
+	 * Constructor.
+	 * @param integer zero-based index of the item in the item collection of datagrid
+	 * @param TListItemType item type
+	 */
+	public function __construct($itemIndex,$dataSourceIndex,$itemType)
+	{
+		$this->_itemIndex=$itemIndex;
+		$this->_dataSourceIndex=$dataSourceIndex;
+		$this->setItemType($itemType);
+		if($itemType===TListItemType::Header)
+			$this->setTableSection(TTableRowSection::Header);
+		else if($itemType===TListItemType::Footer)
+			$this->setTableSection(TTableRowSection::Footer);
+	}
+
+	/**
+	 * @return TListItemType item type.
+	 */
+	public function getItemType()
+	{
+		return $this->_itemType;
+	}
+
+	/**
+	 * @param TListItemType item type
+	 */
+	public function setItemType($value)
+	{
+		$this->_itemType=TPropertyValue::ensureEnum($value,'TListItemType');
+	}
+
+	/**
+	 * @return integer zero-based index of the item in the item collection of datagrid
+	 */
+	public function getItemIndex()
+	{
+		return $this->_itemIndex;
+	}
+
+	/**
+	 * @return integer the index of the datagrid item from the bound data source
+	 */
+	public function getDataSourceIndex()
+	{
+		return $this->_dataSourceIndex;
+	}
+
+	/**
+	 * @return mixed data associated with the item
+	 * @since 3.1.0
+	 */
+	public function getData()
+	{
+		return $this->_data;
+	}
+
+	/**
+	 * @param mixed data to be associated with the item
+	 * @since 3.1.0
+	 */
+	public function setData($value)
+	{
+		$this->_data=$value;
+	}
+
+	/**
+	 * This property is deprecated since v3.1.0.
+	 * @return mixed data associated with the item
+	 * @deprecated deprecated since v3.1.0. Use {@link getData} instead.
+	 */
+	public function getDataItem()
+	{
+		return $this->getData();
+	}
+
+	/**
+	 * This property is deprecated since v3.1.0.
+	 * @param mixed data to be associated with the item
+	 * @deprecated deprecated since version 3.1.0. Use {@link setData} instead.
+	 */
+	public function setDataItem($value)
+	{
+		return $this->setData($value);
+	}
+
+	/**
+	 * This method overrides parent's implementation by wrapping event parameter
+	 * for <b>OnCommand</b> event with item information.
+	 * @param TControl the sender of the event
+	 * @param TEventParameter event parameter
+	 * @return boolean whether the event bubbling should stop here.
+	 */
+	public function bubbleEvent($sender,$param)
+	{
+		if($param instanceof TCommandEventParameter)
+		{
+			$this->raiseBubbleEvent($this,new TDataGridCommandEventParameter($this,$sender,$param));
+			return true;
+		}
+		else
+			return false;
+	}
+}
+
+
+/**
+ * TDataGridPager class.
+ *
+ * TDataGridPager represents a datagrid pager.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ * @since 3.0
+ */
+class TDataGridPager extends TPanel implements INamingContainer
+{
+	private $_dataGrid;
+
+	/**
+	 * Constructor.
+	 * @param TDataGrid datagrid object
+	 */
+	public function __construct($dataGrid)
+	{
+		$this->_dataGrid=$dataGrid;
+	}
+
+	/**
+	 * This method overrides parent's implementation by wrapping event parameter
+	 * for <b>OnCommand</b> event with item information.
+	 * @param TControl the sender of the event
+	 * @param TEventParameter event parameter
+	 * @return boolean whether the event bubbling should stop here.
+	 */
+	public function bubbleEvent($sender,$param)
+	{
+		if($param instanceof TCommandEventParameter)
+		{
+			$this->raiseBubbleEvent($this,new TDataGridCommandEventParameter($this,$sender,$param));
+			return true;
+		}
+		else
+			return false;
+	}
+
+	/**
+	 * @return TDataGrid the datagrid owning this pager
+	 */
+	public function getDataGrid()
+	{
+		return $this->_dataGrid;
+	}
+
+	/**
+	 * @return string item type.
+	 */
+	public function getItemType()
+	{
+		return TListItemType::Pager;
+	}
+}
+
+
+/**
+ * TDataGridItemCollection class.
+ *
+ * TDataGridItemCollection represents a collection of data grid items.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ * @since 3.0
+ */
+class TDataGridItemCollection extends TList
+{
+	/**
+	 * Inserts an item at the specified position.
+	 * This overrides the parent implementation by inserting only TDataGridItem.
+	 * @param integer the speicified position.
+	 * @param mixed new item
+	 * @throws TInvalidDataTypeException if the item to be inserted is not a TDataGridItem.
+	 */
+	public function insertAt($index,$item)
+	{
+		if($item instanceof TDataGridItem)
+			parent::insertAt($index,$item);
+		else
+			throw new TInvalidDataTypeException('datagriditemcollection_datagriditem_required');
+	}
+}
+
+/**
+ * TDataGridColumnCollection class.
+ *
+ * TDataGridColumnCollection represents a collection of data grid columns.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ * @since 3.0
+ */
+class TDataGridColumnCollection extends TList
+{
+	/**
+	 * the control that owns this collection.
+	 * @var TControl
+	 */
+	private $_o;
+
+	/**
+	 * Constructor.
+	 * @param TDataGrid the control that owns this collection.
+	 */
+	public function __construct(TDataGrid $owner)
+	{
+		$this->_o=$owner;
+	}
+
+	/**
+	 * @return TDataGrid the control that owns this collection.
+	 */
+	protected function getOwner()
+	{
+		return $this->_o;
+	}
+
+	/**
+	 * Inserts an item at the specified position.
+	 * This overrides the parent implementation by inserting only TDataGridColumn.
+	 * @param integer the speicified position.
+	 * @param mixed new item
+	 * @throws TInvalidDataTypeException if the item to be inserted is not a TDataGridColumn.
+	 */
+	public function insertAt($index,$item)
+	{
+		if($item instanceof TDataGridColumn)
+		{
+			$item->setOwner($this->_o);
+			parent::insertAt($index,$item);
+		}
+		else
+			throw new TInvalidDataTypeException('datagridcolumncollection_datagridcolumn_required');
+	}
+}
+
+/**
+ * TDataGridPagerMode class.
+ * TDataGridPagerMode defines the enumerable type for the possible modes that a datagrid pager can take.
+ *
+ * The following enumerable values are defined:
+ * - NextPrev: pager buttons are displayed as next and previous pages
+ * - Numeric: pager buttons are displayed as numeric page numbers
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ * @since 3.0.4
+ */
+class TDataGridPagerMode extends TEnumerable
+{
+	const NextPrev='NextPrev';
+	const Numeric='Numeric';
+}
+
+
+/**
+ * TDataGridPagerButtonType class.
+ * TDataGridPagerButtonType defines the enumerable type for the possible types of datagrid pager buttons.
+ *
+ * The following enumerable values are defined:
+ * - LinkButton: link buttons
+ * - PushButton: form submit buttons
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ * @since 3.0.4
+ */
+class TDataGridPagerButtonType extends TEnumerable
+{
+	const LinkButton='LinkButton';
+	const PushButton='PushButton';
+}
+
+
+/**
+ * TDataGridPagerPosition class.
+ * TDataGridPagerPosition defines the enumerable type for the possible positions that a datagrid pager can be located at.
+ *
+ * The following enumerable values are defined:
+ * - Bottom: pager appears only at the bottom of the data grid.
+ * - Top: pager appears only at the top of the data grid.
+ * - TopAndBottom: pager appears on both top and bottom of the data grid.
+ *
+ * @author Qiang Xue <qiang.xue@gmail.com>
+ * @version $Id$
+ * @package System.Web.UI.WebControls
+ * @since 3.0.4
+ */
+class TDataGridPagerPosition extends TEnumerable
+{
+	const Bottom='Bottom';
+	const Top='Top';
+	const TopAndBottom='TopAndBottom';
+}
+