TLinkButton creates a hyperlink style button on the page.
TLinkButton has the same appearance as a hyperlink. However, it is mainly
used to submit data to a page. Like {@link TButton}, you can create either
a submit button or a command button.
A command button has a command name (specified by
the {@link setCommandName CommandName} property) and and a command parameter
(specified by {@link setCommandParameter CommandParameter} property)
associated with the button. This allows you to create multiple TLinkButton
components on a Web page and programmatically determine which one is clicked
with what parameter. You can provide an event handler for
{@link onCommand OnCommand} event to programmatically control the actions performed
when the command button is clicked. In the event handler, you can determine
the {@link setCommandName CommandName} property value and
the {@link setCommandParameter CommandParameter} property value
through the {@link TCommandParameter::getName Name} and
{@link TCommandParameter::getParameter Parameter} properties of the event
parameter which is of type {@link \Prado\Web\UI\TCommandEventParameter}.
A submit button does not have a command name associated with the button
and clicking on it simply posts the Web page back to the server.
By default, a TLinkButton component is a submit button.
You can provide an event handler for the {@link onClick OnClick} event
to programmatically control the actions performed when the submit button is clicked.
Clicking on button can trigger form validation, if
{@link setCausesValidation CausesValidation} is true.
And the validation may be restricted within a certain group of validator
controls by setting {@link setValidationGroup ValidationGroup} property.
If validation is successful, the data will be post back to the same page.
TLinkButton will display the {@link setText Text} property value
as the hyperlink text. If {@link setText Text} is empty, the body content
of TLinkButton will be displayed. Therefore, you can use TLinkButton
as an image button by enclosing an <img> tag as the body of TLinkButton.
/**
* 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 <b>Sort</b> command upon user click.
*
* @param TTableCell the cell to be initialized
* @param integer the index to the Columns property that the cell resides in.
*/
protected function initializeHeaderCell($cell, $columnIndex)
{
$text = $this->getHeaderText();
if (($classPath = $this->getHeaderRenderer()) !== '') {
$control = Prado::createComponent($classPath);
$cell->getControls()->add($control);
if ($control instanceof \Prado\IDataRenderer) {
if ($control instanceof IItemDataRenderer) {
$item = $cell->getParent();
$control->setItemIndex($item->getItemIndex());
$control->setItemType($item->getItemType());
}
$control->setData($text);
}
} else {
if ($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);
} else {
if ($text !== '') {
$button = new TLinkButton();
$button->setText($text);
$button->setCommandName(TDataGrid::CMD_SORT);
$button->setCommandParameter($sortExpression);
$button->setCausesValidation(false);
$cell->getControls()->add($button);
} else {
$cell->setText(' ');
}
}
} else {
if (($url = $this->getHeaderImageUrl()) !== '') {
$image = new TImage();
$image->setImageUrl($url);
if ($text !== '') {
$image->setAlternateText($text);
}
$cell->getControls()->add($image);
} else {
if ($text !== '') {
$cell->setText($text);
} else {
$cell->setText(' ');
}
}
}
}
}
/**
* Instantiates the template.
* It creates a {@link TLinkButton}.
* @param TControl parent to hold the content within the template
*/
public function instantiateIn($parent)
{
$button = new TLinkButton();
$button->setID(TWizard::ID_SIDEBAR_BUTTON);
$parent->getControls()->add($button);
}
/**
* Ensures that the anchor is rendered correctly when its Enabled property
* changes in a callback
* @param bool enabled
*/
public function setEnabled($value)
{
if (parent::getEnabled() === $value) {
return;
}
parent::setEnabled($value);
if ($this->getActiveControl()->canUpdateClientSide()) {
if ($this->getEnabled(true)) {
$nop = "javascript:;//" . $this->getClientID();
$this->getPage()->getCallbackClient()->setAttribute($this, 'href', $nop);
$this->getActiveControl()->registerCallbackClientScript($this->getClientClassName(), $this->getPostBackOptions());
} else {
$this->getPage()->getCallbackClient()->setAttribute($this, 'href', false);
}
}
}
