TButton creates a click button on the page. It is mainly used to submit data to a page.
TButton raises two server-side events, {@link onClick OnClick} and {@link onCommand OnCommand},
when it is clicked on the client-side. The difference between these two events
is that the event {@link onCommand OnCommand} is bubbled up to the button's ancestor controls.
And within the event parameter for {@link onCommand OnCommand} contains the reference
to the {@link setCommandName CommandName} and {@link setCommandParameter CommandParameter}
property values that are set for the button object. This allows you to create multiple TButton
components on a Web page and programmatically determine which one is clicked
with what parameter.
Clicking on button can also trigger form validation, if
{@link setCausesValidation CausesValidation} is true.
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.
TButton displays the {@link setText Text} property as the button caption.
TButton can be one of three {@link setButtonType ButtonType}: Submit, Button and Reset.
By default, it is a Submit button and the form submission uses the browser's
default submission capability. If it is Button or Reset, postback may occur
if one of the following conditions is met:
- an event handler is attached to {@link onClick OnClick} event;
- an event handler is attached to {@link onCommand OnCommand} event;
- the button is in a non-empty validation group.
In addition, clicking on a Reset button will clear up all input fields
if the button does not cause a postback.
/**
* 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 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($buttonType, $enabled, $text, $commandName, $commandParameter)
{
if ($buttonType === TPagerButtonType::LinkButton) {
if ($enabled) {
$button = new TLinkButton();
} else {
$button = new TLabel();
$button->setText($text);
$button->setCssClass($this->getButtonCssClass());
return $button;
}
} else {
if ($buttonType === TPagerButtonType::ImageButton) {
$button = new TImageButton();
$button->setImageUrl($this->getPageImageUrl($text, $commandName));
} else {
$button = new TButton();
}
if (!$enabled) {
$button->setEnabled(false);
}
}
$button->setText($text);
$button->setCommandName($commandName);
$button->setCommandParameter($commandParameter);
$button->setCausesValidation(false);
$button->setCssClass($this->getButtonCssClass());
return $button;
}
/**
* Creates a pager button.
* Depending on the button type, a TLinkButton or a TButton may be created.
* If it is enabled (clickable), its command name and parameter will also be set.
* Derived classes may override this method to create additional types of buttons, such as TImageButton.
* @param mixed the container pager instance of TActiveDatagridPager
* @param string button type, either LinkButton or PushButton
* @param boolean whether the button should be enabled
* @param string caption of the button
* @param string CommandName corresponding to the OnCommand event of the button
* @param string CommandParameter corresponding to the OnCommand event of the button
* @return mixed the button instance
*/
protected function createPagerButton($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 $button;
}
/**
* Ensure that the ID attribute is rendered and registers the javascript code
* for initializing the active control.
*/
protected function addAttributesToRender($writer)
{
parent::addAttributesToRender($writer);
$writer->addAttribute('id', $this->getClientID());
$this->getActiveControl()->registerCallbackClientScript($this->getClientClassName(), $this->getPostBackOptions());
}
