Gecko [ ifk.uw.edu.pl ]

Name	Size	Permission
assets	[ DIR ]	drwxr-xr-x
IDataSource.php	507 B	-rw-r--r--
IItemDataRenderer.php	1.34 KB	-rw-r--r--
IListControlAdapter.php	1.22 KB	-rw-r--r--
IRepeatInfoUser.php	1.55 KB	-rw-r--r--
IStyleable.php	774 B	-rw-r--r--
TAccordion.php	16.08 KB	-rw-r--r--
TAccordionView.php	4.45 KB	-rw-r--r--
TAccordionViewCollection.php	1.57 KB	-rw-r--r--
TBaseDataList.php	5.45 KB	-rw-r--r--
TBaseValidator.php	19.79 KB	-rw-r--r--
TBoundColumn.php	7.11 KB	-rw-r--r--
TBulletStyle.php	913 B	-rw-r--r--
TBulletedList.php	12.14 KB	-rw-r--r--
TBulletedListDisplayMode.php	917 B	-rw-r--r--
TBulletedListEventParameter.ph...	993 B	-rw-r--r--
TButton.php	11.42 KB	-rw-r--r--
TButtonColumn.php	8.5 KB	-rw-r--r--
TButtonColumnType.php	791 B	-rw-r--r--
TButtonTag.php	705 B	-rw-r--r--
TButtonType.php	756 B	-rw-r--r--
TCaptcha.php	16.31 KB	-rw-r--r--
TCaptchaValidator.php	4 KB	-rw-r--r--
TCheckBox.php	15.02 KB	-rw-r--r--
TCheckBoxColumn.php	3.68 KB	-rw-r--r--
TCheckBoxItem.php	520 B	-rw-r--r--
TCheckBoxList.php	14.43 KB	-rw-r--r--
TCircleHotSpot.php	1.84 KB	-rw-r--r--
TClientScript.php	4.41 KB	-rw-r--r--
TClientSideValidationSummaryOp...	2.38 KB	-rw-r--r--
TColorPicker.php	6.83 KB	-rw-r--r--
TColorPickerClientSide.php	847 B	-rw-r--r--
TColorPickerMode.php	815 B	-rw-r--r--
TCompareValidator.php	7.5 KB	-rw-r--r--
TCompleteWizardStep.php	960 B	-rw-r--r--
TConditional.php	4.33 KB	-rw-r--r--
TContent.php	1.67 KB	-rw-r--r--
TContentDirection.php	811 B	-rw-r--r--
TContentPlaceHolder.php	1.73 KB	-rw-r--r--
TCustomValidator.php	4.46 KB	-rw-r--r--
TDataBoundControl.php	15.37 KB	-rw-r--r--
TDataGrid.php	48.32 KB	-rw-r--r--
TDataGridColumn.php	17.06 KB	-rw-r--r--
TDataGridColumnCollection.php	1.83 KB	-rw-r--r--
TDataGridCommandEventParameter...	2.06 KB	-rw-r--r--
TDataGridItem.php	3.62 KB	-rw-r--r--
TDataGridItemCollection.php	1.34 KB	-rw-r--r--
TDataGridItemEventParameter.ph...	1.4 KB	-rw-r--r--
TDataGridItemRenderer.php	539 B	-rw-r--r--
TDataGridPageChangedEventParam...	1.84 KB	-rw-r--r--
TDataGridPager.php	1.75 KB	-rw-r--r--
TDataGridPagerButtonType.php	1022 B	-rw-r--r--
TDataGridPagerEventParameter.p...	1.42 KB	-rw-r--r--
TDataGridPagerMode.php	1.04 KB	-rw-r--r--
TDataGridPagerPosition.php	1.16 KB	-rw-r--r--
TDataGridPagerStyle.php	7.44 KB	-rw-r--r--
TDataGridSortCommandEventParam...	1.93 KB	-rw-r--r--
TDataList.php	46.45 KB	-rw-r--r--
TDataListCommandEventParameter...	1.81 KB	-rw-r--r--
TDataListItem.php	3.29 KB	-rw-r--r--
TDataListItemCollection.php	1.06 KB	-rw-r--r--
TDataListItemEventParameter.ph...	1.16 KB	-rw-r--r--
TDataListItemRenderer.php	4.6 KB	-rw-r--r--
TDataRenderer.php	1.11 KB	-rw-r--r--
TDataSize.php	4.22 KB	-rw-r--r--
TDataSourceControl.php	1.36 KB	-rw-r--r--
TDataSourceSelectParameters.ph...	1.51 KB	-rw-r--r--
TDataSourceView.php	2.23 KB	-rw-r--r--
TDataTypeValidator.php	3.89 KB	-rw-r--r--
TDatePicker.php	26.21 KB	-rw-r--r--
TDatePickerClientScript.php	1.22 KB	-rw-r--r--
TDatePickerInputMode.php	746 B	-rw-r--r--
TDatePickerMode.php	1.08 KB	-rw-r--r--
TDatePickerPositionMode.php	766 B	-rw-r--r--
TDisplayStyle.php	994 B	-rw-r--r--
TDropDownList.php	4.58 KB	-rw-r--r--
TDropDownListColumn.php	10.06 KB	-rw-r--r--
TEditCommandColumn.php	7.97 KB	-rw-r--r--
TEmailAddressValidator.php	2.68 KB	-rw-r--r--
TExpression.php	1.42 KB	-rw-r--r--
TFileUpload.php	11.86 KB	-rw-r--r--
TFileUploadItem.php	4.03 KB	-rw-r--r--
TFlushOutput.php	2.25 KB	-rw-r--r--
TFont.php	8.93 KB	-rw-r--r--
TGravatar.php	4.65 KB	-rw-r--r--
THead.php	5 KB	-rw-r--r--
THeader1.php	675 B	-rw-r--r--
THeader2.php	675 B	-rw-r--r--
THeader3.php	675 B	-rw-r--r--
THeader4.php	674 B	-rw-r--r--
THeader5.php	674 B	-rw-r--r--
THeader6.php	674 B	-rw-r--r--
THiddenField.php	5.82 KB	-rw-r--r--
THorizontalAlign.php	921 B	-rw-r--r--
THotSpot.php	8.73 KB	-rw-r--r--
THotSpotCollection.php	1.02 KB	-rw-r--r--
THotSpotMode.php	901 B	-rw-r--r--
THtmlArea.php	12.41 KB	-rw-r--r--
THtmlArea5.php	11.53 KB	-rw-r--r--
THtmlElement.php	1.62 KB	-rw-r--r--
THyperLink.php	7.41 KB	-rw-r--r--
THyperLinkColumn.php	7.61 KB	-rw-r--r--
TImage.php	4.29 KB	-rw-r--r--
TImageButton.php	11.67 KB	-rw-r--r--
TImageClickEventParameter.php	1.52 KB	-rw-r--r--
TImageMap.php	6.86 KB	-rw-r--r--
TImageMapEventParameter.php	1.06 KB	-rw-r--r--
TInlineFrame.php	7.89 KB	-rw-r--r--
TInlineFrameAlign.php	1018 B	-rw-r--r--
TInlineFrameScrollBars.php	917 B	-rw-r--r--
TItemDataRenderer.php	2.17 KB	-rw-r--r--
TJavascriptLogger.php	2.8 KB	-rw-r--r--
TKeyboard.php	5.92 KB	-rw-r--r--
TLabel.php	3.95 KB	-rw-r--r--
TLinkButton.php	10.45 KB	-rw-r--r--
TListBox.php	6.57 KB	-rw-r--r--
TListControl.php	24.23 KB	-rw-r--r--
TListControlValidator.php	5.84 KB	-rw-r--r--
TListItem.php	4.93 KB	-rw-r--r--
TListItemType.php	1.11 KB	-rw-r--r--
TListSelectionMode.php	684 B	-rw-r--r--
TLiteral.php	2.82 KB	-rw-r--r--
TLiteralColumn.php	4.08 KB	-rw-r--r--
TMarkdown.php	1.99 KB	-rw-r--r--
TMetaTag.php	3.53 KB	-rw-r--r--
TMetaTagCollection.php	1.83 KB	-rw-r--r--
TMultiView.php	8.34 KB	-rw-r--r--
TOutputCache.php	15.99 KB	-rw-r--r--
TOutputCacheCalculateKeyEventP...	1.04 KB	-rw-r--r--
TOutputCacheCheckDependencyEve...	1.38 KB	-rw-r--r--
TOutputCacheTextWriterMulti.ph...	975 B	-rw-r--r--
TPageLoadTime.php	1.31 KB	-rw-r--r--
TPager.php	21.73 KB	-rw-r--r--
TPagerButtonType.php	714 B	-rw-r--r--
TPagerMode.php	838 B	-rw-r--r--
TPagerPageChangedEventParamete...	1.54 KB	-rw-r--r--
TPanel.php	6.39 KB	-rw-r--r--
TPanelStyle.php	8.09 KB	-rw-r--r--
TPlaceHolder.php	616 B	-rw-r--r--
TPolygonHotSpot.php	1.11 KB	-rw-r--r--
TRadioButton.php	9.39 KB	-rw-r--r--
TRadioButtonItem.php	533 B	-rw-r--r--
TRadioButtonList.php	2.29 KB	-rw-r--r--
TRangeValidationDataType.php	696 B	-rw-r--r--
TRangeValidator.php	9.76 KB	-rw-r--r--
TRatingList.php	8.75 KB	-rw-r--r--
TReCaptcha.php	11.79 KB	-rw-r--r--
TReCaptcha2.php	10.95 KB	-rw-r--r--
TReCaptcha2Validator.php	3.43 KB	-rw-r--r--
TReCaptchaValidator.php	4.19 KB	-rw-r--r--
TReadOnlyDataSource.php	1.1 KB	-rw-r--r--
TReadOnlyDataSourceView.php	1.01 KB	-rw-r--r--
TRectangleHotSpot.php	2.36 KB	-rw-r--r--
TRegularExpressionValidator.ph...	4.16 KB	-rw-r--r--
TRepeatDirection.php	681 B	-rw-r--r--
TRepeatInfo.php	13.51 KB	-rw-r--r--
TRepeatLayout.php	872 B	-rw-r--r--
TRepeater.php	23.8 KB	-rw-r--r--
TRepeaterCommandEventParameter...	1.81 KB	-rw-r--r--
TRepeaterItem.php	2.83 KB	-rw-r--r--
TRepeaterItemCollection.php	1.07 KB	-rw-r--r--
TRepeaterItemEventParameter.ph...	1.13 KB	-rw-r--r--
TRepeaterItemRenderer.php	1.24 KB	-rw-r--r--
TRequiredFieldValidator.php	4.56 KB	-rw-r--r--
TSafeHtml.php	2.07 KB	-rw-r--r--
TScrollBars.php	953 B	-rw-r--r--
TServerValidateEventParameter....	1.37 KB	-rw-r--r--
TSlider.php	14.93 KB	-rw-r--r--
TSliderClientScript.php	1.78 KB	-rw-r--r--
TSliderDirection.php	749 B	-rw-r--r--
TStatements.php	1.44 KB	-rw-r--r--
TStyle.php	9.84 KB	-rw-r--r--
TStyleSheet.php	3.62 KB	-rw-r--r--
TTabPanel.php	14.67 KB	-rw-r--r--
TTabView.php	4.83 KB	-rw-r--r--
TTabViewCollection.php	1.55 KB	-rw-r--r--
TTable.php	9.63 KB	-rw-r--r--
TTableCaptionAlign.php	862 B	-rw-r--r--
TTableCell.php	5.77 KB	-rw-r--r--
TTableCellCollection.php	1.1 KB	-rw-r--r--
TTableFooterRow.php	882 B	-rw-r--r--
TTableGridLines.php	902 B	-rw-r--r--
TTableHeaderCell.php	2.4 KB	-rw-r--r--
TTableHeaderRow.php	882 B	-rw-r--r--
TTableHeaderScope.php	766 B	-rw-r--r--
TTableItemStyle.php	5.5 KB	-rw-r--r--
TTableRow.php	3.8 KB	-rw-r--r--
TTableRowCollection.php	1.08 KB	-rw-r--r--
TTableRowSection.php	761 B	-rw-r--r--
TTableStyle.php	8.84 KB	-rw-r--r--
TTemplateColumn.php	7.93 KB	-rw-r--r--
TTemplatedWizardStep.php	2.93 KB	-rw-r--r--
TTextAlign.php	608 B	-rw-r--r--
TTextBox.php	19.32 KB	-rw-r--r--
TTextBoxAutoCompleteType.php	1.87 KB	-rw-r--r--
TTextBoxMode.php	2.3 KB	-rw-r--r--
TTextHighlighter.php	6.53 KB	-rw-r--r--
TTextProcessor.php	2.28 KB	-rw-r--r--
TValidationCompareOperator.php	959 B	-rw-r--r--
TValidationDataType.php	749 B	-rw-r--r--
TValidationSummary.php	11.78 KB	-rw-r--r--
TValidationSummaryDisplayMode....	1.09 KB	-rw-r--r--
TValidationSummaryDisplayStyle...	1017 B	-rw-r--r--
TValidatorClientSide.php	2.96 KB	-rw-r--r--
TValidatorDisplayStyle.php	951 B	-rw-r--r--
TVerticalAlign.php	836 B	-rw-r--r--
TView.php	2.23 KB	-rw-r--r--
TViewCollection.php	1.09 KB	-rw-r--r--
TWebControl.php	12.65 KB	-rw-r--r--
TWebControlAdapter.php	1.98 KB	-rw-r--r--
TWebControlDecorator.php	10.94 KB	-rw-r--r--
TWizard.php	41.24 KB	-rw-r--r--
TWizardFinishNavigationTemplat...	1.49 KB	-rw-r--r--
TWizardNavigationButtonStyle.p...	3.89 KB	-rw-r--r--
TWizardNavigationButtonType.ph...	825 B	-rw-r--r--
TWizardNavigationContainer.php	1.85 KB	-rw-r--r--
TWizardNavigationEventParamete...	2.15 KB	-rw-r--r--
TWizardNavigationTemplate.php	2.29 KB	-rw-r--r--
TWizardSideBarListItemTemplate...	907 B	-rw-r--r--
TWizardSideBarTemplate.php	1003 B	-rw-r--r--
TWizardStartNavigationTemplate...	1.21 KB	-rw-r--r--
TWizardStep.php	2.34 KB	-rw-r--r--
TWizardStepCollection.php	1.79 KB	-rw-r--r--
TWizardStepNavigationTemplate....	1.45 KB	-rw-r--r--
TWizardStepType.php	1.01 KB	-rw-r--r--
TXmlTransform.php	5.76 KB	-rw-r--r--

Code Editor : TDataGridColumn.php

<?php
/**
 * TDataGridColumn class file
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link https://github.com/pradosoft/prado
 * @license https://github.com/pradosoft/prado/blob/master/LICENSE
 */

namespace Prado\Web\UI\WebControls;

use Exception;
use Prado\Prado;
use Prado\TPropertyValue;
use Prado\Exceptions\TInvalidDataValueException;
use Prado\Util\TDataFieldAccessor;
use Prado\Web\UI\TControl;

/**
 * TDataGridColumn class
 *
 * TDataGridColumn serves as the base class for the different column types of
 * the {@link TDataGrid} control.
 * TDataGridColumn defines the properties and methods that are common among
 * all datagrid column types. In particular, it initializes header and footer
 * cells according to {@link setHeaderText HeaderText} and {@link getHeaderStyle HeaderStyle}
 * {@link setFooterText FooterText} and {@link getFooterStyle FooterStyle} properties.
 * If {@link setHeaderImageUrl HeaderImageUrl} is specified, the image
 * will be displayed instead in the header cell.
 * The {@link getItemStyle ItemStyle} is applied to cells that belong to
 * non-header and -footer datagrid items.
 *
 * When the datagrid enables sorting, if the {@link setSortExpression SortExpression}
 * is not empty, the header cell will display a button (linkbutton or imagebutton)
 * that will bubble the sort command event to the datagrid.
 *
 * Since v3.1.0, TDataGridColumn has introduced two new properties {@link setHeaderRenderer HeaderRenderer}
 * and {@link setFooterRenderer FooterRenderer} which can be used to specify
 * the layout of header and footer column cells.
 * A renderer refers to a control class that is to be instantiated as a control.
 * For more details, see {@link TRepeater} and {@link TDataList}.
 *
 * Since v3.1.1, TDataGridColumn has introduced {@link setEnableCellGrouping EnableCellGrouping}.
 * If a column has this property set true, consecutive cells having the same content in this
 * column will be grouped into one cell.
 * Note, there are some limitations to cell grouping. We determine the cell content according to
 * the cell's {@link TTableCell::getText Text} property. If the text is empty and the cell has
 * some child controls, we will pick up the first control who implements {@link \Prado\IDataRenderer}
 * and obtain its {@link \Prado\IDataRenderer::getData Data} property.
 *
 * The following datagrid column types are provided by the framework currently,
 * - {@link TBoundColumn}, associated with a specific field in datasource and displays the corresponding data.
 * - {@link TEditCommandColumn}, displaying edit/update/cancel command buttons
 * - {@link TDropDownListColumn}, displaying a dropdown list when the item is in edit state
 * - {@link TButtonColumn}, displaying generic command buttons that may be bound to specific field in datasource.
 * - {@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.
 *
 * To create your own column class, simply override {@link initializeCell()} method,
 * which is the major logic for managing the data and presentation of cells in the column.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 3.0
 */
abstract class TDataGridColumn extends \Prado\TApplicationComponent
{
	private $_id = '';
	private $_owner;
	private $_viewState = [];

/**
	 * @return string the ID of the column.
	 */
	public function getID()
	{
		return $this->_id;
	}

/**
	 * Sets the ID of the column.
	 * By explicitly specifying the column ID, one can access the column
	 * by $templateControl->ColumnID.
	 * @param string $value the ID of the column.
	 * @throws TInvalidDataValueException if the ID is of bad format
	 */
	public function setID($value)
	{
		if (!preg_match(TControl::ID_FORMAT, $value)) {
			throw new TInvalidDataValueException('datagridcolumn_id_invalid', get_class($this), $value);
		}
		$this->_id = $value;
	}

/**
	 * @return string the text to be displayed in the header of this column
	 */
	public function getHeaderText()
	{
		return $this->getViewState('HeaderText', '');
	}

/**
	 * @param string $value text to be displayed in the header of this column
	 */
	public function setHeaderText($value)
	{
		$this->setViewState('HeaderText', $value, '');
	}

/**
	 * @return string the url of the image to be displayed in header
	 */
	public function getHeaderImageUrl()
	{
		return $this->getViewState('HeaderImageUrl', '');
	}

/**
	 * @param string $value the url of the image to be displayed in header
	 */
	public function setHeaderImageUrl($value)
	{
		$this->setViewState('HeaderImageUrl', $value, '');
	}

/**
	 * @return string the class name for the column header cell renderer. Defaults to empty, meaning not set.
	 * @since 3.1.0
	 */
	public function getHeaderRenderer()
	{
		return $this->getViewState('HeaderRenderer', '');
	}

/**
	 * Sets the column header cell renderer class.
	 *
	 * If not empty, the class will be used to instantiate as a child control in the column header cell.
	 * If the class implements {@link \Prado\IDataRenderer}, the Data property
	 * will be set as the {@link getFooterText FooterText}.
	 *
	 * @param string $value the renderer class name in namespace format.
	 * @since 3.1.0
	 */
	public function setHeaderRenderer($value)
	{
		$this->setViewState('HeaderRenderer', $value, '');
	}

/**
	 * @param bool $createStyle whether to create a style if previously not existing
	 * @return TTableItemStyle the style for header
	 */
	public function getHeaderStyle($createStyle = true)
	{
		if (($style = $this->getViewState('HeaderStyle', null)) === null && $createStyle) {
			$style = new TTableItemStyle();
			$this->setViewState('HeaderStyle', $style, null);
		}
		return $style;
	}

/**
	 * @return string the text to be displayed in the footer of this column
	 */
	public function getFooterText()
	{
		return $this->getViewState('FooterText', '');
	}

/**
	 * @param string $value text to be displayed in the footer of this column
	 */
	public function setFooterText($value)
	{
		$this->setViewState('FooterText', $value, '');
	}

/**
	 * @return string the class name for the column footer cell renderer. Defaults to empty, meaning not set.
	 * @since 3.1.0
	 */
	public function getFooterRenderer()
	{
		return $this->getViewState('FooterRenderer', '');
	}

/**
	 * Sets the column footer cell renderer class.
	 *
	 * If not empty, the class will be used to instantiate as a child control in the column footer cell.
	 * If the class implements {@link \Prado\IDataRenderer}, the Data property
	 * will be set as the {@link getFooterText FooterText}.
	 *
	 * @param string $value the renderer class name in namespace format.
	 * @since 3.1.0
	 */
	public function setFooterRenderer($value)
	{
		$this->setViewState('FooterRenderer', $value, '');
	}

/**
	 * @param bool $createStyle whether to create a style if previously not existing
	 * @return TTableItemStyle the style for footer
	 */
	public function getFooterStyle($createStyle = true)
	{
		if (($style = $this->getViewState('FooterStyle', null)) === null && $createStyle) {
			$style = new TTableItemStyle();
			$this->setViewState('FooterStyle', $style, null);
		}
		return $style;
	}

/**
	 * @param bool $createStyle whether to create a style if previously not existing
	 * @return TTableItemStyle the style for item
	 */
	public function getItemStyle($createStyle = true)
	{
		if (($style = $this->getViewState('ItemStyle', null)) === null && $createStyle) {
			$style = new TTableItemStyle();
			$this->setViewState('ItemStyle', $style, null);
		}
		return $style;
	}

/**
	 * @return string the name of the field or expression for sorting
	 */
	public function getSortExpression()
	{
		return $this->getViewState('SortExpression', '');
	}

/**
	 * @param string $value the name of the field or expression for sorting
	 */
	public function setSortExpression($value)
	{
		$this->setViewState('SortExpression', $value, '');
	}

/**
	 * @return bool whether cells having the same content should be grouped together. Defaults to false.
	 * @since 3.1.1
	 */
	public function getEnableCellGrouping()
	{
		return $this->getViewState('EnableCellGrouping', false);
	}

/**
	 * @param bool $value whether cells having the same content should be grouped together.
	 * @since 3.1.1
	 */
	public function setEnableCellGrouping($value)
	{
		$this->setViewState('EnableCellGrouping', TPropertyValue::ensureBoolean($value), false);
	}

/**
	 * @param mixed $checkParents
	 * @return bool whether the column is visible. Defaults to true.
	 */
	public function getVisible($checkParents = true)
	{
		return $this->getViewState('Visible', true);
	}

/**
	 * @param bool $value whether the column is visible
	 */
	public function setVisible($value)
	{
		$this->setViewState('Visible', TPropertyValue::ensureBoolean($value), true);
	}

/**
	 * Returns a viewstate value.
	 *
	 * @param string $key the name of the viewstate value to be returned
	 * @param mixed $defaultValue the default value. If $key is not found in viewstate, $defaultValue will be returned
	 * @return mixed the viewstate value corresponding to $key
	 */
	protected function getViewState($key, $defaultValue = null)
	{
		return $this->_viewState[$key] ?? $defaultValue;
	}

/**
	 * Sets a viewstate value.
	 *
	 * Make sure that the viewstate value must be serializable and unserializable.
	 * @param string $key the name of the viewstate value
	 * @param mixed $value the viewstate value to be set
	 * @param null|mixed $defaultValue default value. If $value===$defaultValue, the item will be cleared from the viewstate.
	 */
	protected function setViewState($key, $value, $defaultValue = null)
	{
		if ($value === $defaultValue) {
			unset($this->_viewState[$key]);
		} else {
			$this->_viewState[$key] = $value;
		}
	}

/**
	 * Loads persistent state values.
	 * @param mixed $state state values
	 */
	public function loadState($state)
	{
		$this->_viewState = $state;
	}

/**
	 * Saves persistent state values.
	 * @return mixed values to be saved
	 */
	public function saveState()
	{
		return $this->_viewState;
	}

/**
	 * @return TDataGrid datagrid that owns this column
	 */
	public function getOwner()
	{
		return $this->_owner;
	}

/**
	 * @param TDataGrid $value datagrid object that owns this column
	 */
	public function setOwner(TDataGrid $value)
	{
		$this->_owner = $value;
	}

/**
	 * Initializes the column.
	 * This method is invoked by {@link TDataGrid} when the column
	 * is about to be used to initialize datagrid items.
	 * Derived classes may override this method to do additional initialization.
	 */
	public function initialize()
	{
	}

/**
	 * Fetches the value of the data at the specified field.
	 * If the data is an array, the field is used as an array key.
	 * If the data is an of {@link TMap}, {@link TList} or their derived class,
	 * the field is used as a key value.
	 * If the data is a component, the field is used as the name of a property.
	 * @param mixed $data data containing the field of value
	 * @param string $field the data field
	 * @throws TInvalidDataValueException if the data or the field is invalid.
	 * @return mixed data value at the specified field
	 */
	protected function getDataFieldValue($data, $field)
	{
		return TDataFieldAccessor::getDataFieldValue($data, $field);
	}

/**
	 * Initializes the specified cell to its initial values.
	 * The default implementation sets the content of header and footer cells.
	 * If sorting is enabled by the grid and sort expression is specified in the column,
	 * the header cell will show a link/image button. Otherwise, the header/footer cell
	 * will only show static text/image.
	 * This method can be overriden to provide customized intialization to column cells.
	 * @param TTableCell $cell the cell to be initialized.
	 * @param int $columnIndex the index to the Columns property that the cell resides in.
	 * @param string $itemType the type of cell (Header,Footer,Item,AlternatingItem,EditItem,SelectedItem)
	 */
	public function initializeCell($cell, $columnIndex, $itemType)
	{
		if ($itemType === TListItemType::Header) {
			$this->initializeHeaderCell($cell, $columnIndex);
		} elseif ($itemType === TListItemType::Footer) {
			$this->initializeFooterCell($cell, $columnIndex);
		}
	}

/**
	 * Returns a value indicating whether this column allows sorting.
	 * The column allows sorting only when {@link getSortExpression SortExpression}
	 * is not empty and the datagrid allows sorting.
	 * @return bool whether this column allows sorting
	 */
	public function getAllowSorting()
	{
		return $this->getSortExpression() !== '' && (!$this->_owner || $this->_owner->getAllowSorting());
	}

/**
	 * Initializes the header cell.
	 *
	 * This method attempts to use {@link getHeaderRenderer HeaderRenderer} to
	 * instantiate the header cell. If that is not available, it will populate
	 * the cell with an image or a text string, depending on {@link getHeaderImageUrl HeaderImageUrl}
	 * and {@link getHeaderText HeaderText} property values.
	 *
	 * If the column allows sorting, image or text will be created as
	 * a button which issues Sort command upon user click.
	 *
	 * @param TTableCell $cell the cell to be initialized
	 * @param int $columnIndex the index to the Columns property that the cell resides in.
	 */
	protected function initializeHeaderCell($cell, $columnIndex)
	{
		$text = $this->getHeaderText();
		if (($classPath = $this->getHeaderRenderer()) !== '') {
			$this->initializeCellRendererControl($cell, $classPath, $text);
		} elseif ($this->getAllowSorting()) {
			$sortExpression = $this->getSortExpression();
			if (($url = $this->getHeaderImageUrl()) !== '') {
				$button = new TImageButton();
				$button->setImageUrl($url);
				$button->setCommandName(TDataGrid::CMD_SORT);
				$button->setCommandParameter($sortExpression);
				if ($text !== '') {
					$button->setAlternateText($text);
				}
				$button->setCausesValidation(false);
				$cell->getControls()->add($button);
			} elseif ($text !== '') {
				$button = new TLinkButton();
				$button->setText($text);
				$button->setCommandName(TDataGrid::CMD_SORT);
				$button->setCommandParameter($sortExpression);
				$button->setCausesValidation(false);
				$cell->getControls()->add($button);
			} else {
				$cell->setText('&nbsp;');
			}
		} else {
			if (($url = $this->getHeaderImageUrl()) !== '') {
				$image = new TImage();
				$image->setImageUrl($url);
				if ($text !== '') {
					$image->setAlternateText($text);
				}
				$cell->getControls()->add($image);
			} elseif ($text !== '') {
				$cell->setText($text);
			} else {
				$cell->setText('&nbsp;');
			}
		}
	}

/**
	 * Initializes the footer cell.
	 *
	 * This method attempts to use {@link getFooterRenderer FooterRenderer} to
	 * instantiate the footer cell. If that is not available, it will populate
	 * the cell with a text string specified by {@link getFooterImageUrl FooterImageUrl}
	 *
	 * @param TTableCell $cell the cell to be initialized
	 * @param int $columnIndex the index to the Columns property that the cell resides in.
	 */
	protected function initializeFooterCell($cell, $columnIndex)
	{
		$text = $this->getFooterText();
		if (($classPath = $this->getFooterRenderer()) !== '') {
			$this->initializeCellRendererControl($cell, $classPath, $text);
		} elseif ($text !== '') {
			$cell->setText($text);
		} else {
			$cell->setText('&nbsp;');
		}
	}

/**
	 * Initializes a cell creating a renderer control.
	 *
	 * @param TTableCell $cell the cell to be initialized
	 * @param string $classPath the rendered class that will be instanciated.
	 * @param mixed $data used to initialize the control
	 */
	protected function initializeCellRendererControl($cell, $classPath, $data = null)
	{
		$control = Prado::createComponent($classPath);
		$cell->getControls()->add($control);
		if ($control instanceof \Prado\IDataRenderer) {
			if ($control instanceof IItemDataRenderer && ($item = $cell->getParent()) instanceof IItemDataRenderer) {
				$control->setItemIndex($item->getItemIndex());
				$control->setItemType($item->getItemType());
			}
			if ($data !== null) {
				$control->setData($data);
			}
		}
		return $control;
	}

/**
	 * Formats the text value according to a format string.
	 * If the format string is empty, the original value is converted into
	 * a string and returned.
	 * If the format string starts with '#', the string is treated as a PHP expression
	 * within which the token '{0}' is translated with the data value to be formated.
	 * Otherwise, the format string and the data value are passed
	 * as the first and second parameters in {@link sprintf}.
	 * @param string $formatString format string
	 * @param mixed $value the data to be formatted
	 * @return string the formatted result
	 */
	protected function formatDataValue($formatString, $value)
	{
		if ($formatString === '') {
			return TPropertyValue::ensureString($value);
		} elseif ($formatString[0] === '#') {
			$expression = strtr(substr($formatString, 1), ['{0}' => '$value']);
			try {
				return eval("return $expression;");
			} catch (Exception $e) {
				throw new TInvalidDataValueException('datagridcolumn_expression_invalid', get_class($this), $expression, $e->getMessage());
			}
		} else {
			return sprintf($formatString, $value);
		}
	}
}

${this.title}

Code Editor : TDataGridColumn.php