<?php
/**
 * TActiveHiddenField class file.
 *
 * @author Carl G. Mathisen <carlgmathisen@gmail.com>
 * @link http://www.pradosoft.com/
 * @copyright Copyright &copy; 2005-2014 PradoSoft
 * @license http://www.pradosoft.com/license/
 * @package Prado\Web\UI\ActiveControls
 */

namespace Prado\Web\UI\ActiveControls;

Prado::using('System.Web.UI.ActiveControls.TActiveControlAdapter');

/**
 * TActiveHiddenField class
 *
 * TActiveHiddenField displays a hidden input field on a Web page.
 * The value of the input field can be accessed via {@link getValue Value} property.
 *
 * @author Carl G. Mathisen <carlgmathisen@gmail.com>
 * @package Prado\Web\UI\ActiveControls
 * @since 3.1
 */
class TActiveHiddenField extends THiddenField implements ICallbackEventHandler, IActiveControl
{
    /**
	 * Creates a new callback control, sets the adapter to
	 * TActiveControlAdapter. If you override this class, be sure to set the
	 * adapter appropriately by, for example, by calling this constructor.
	 */
	public function __construct()
	{
		parent::__construct();
		$this->setAdapter(new TActiveControlAdapter($this));
	}

	/**
	 * @return TBaseActiveCallbackControl standard callback control options.
	 */
	public function getActiveControl()
	{
		return $this->getAdapter()->getBaseActiveControl();
	}

	/**
	 * @return TCallbackClientSide client side request options.
	 */
	public function getClientSide()
	{
		return $this->getAdapter()->getBaseActiveControl()->getClientSide();
	}

	/**
	 * Client-side Value property can only be updated after the OnLoad stage.
	 * @param string text content for the hidden field
	 */
	public function setValue($value)
	{
		parent::setValue($value);
		if($this->getActiveControl()->canUpdateClientSide() && $this->getHasLoadedPostData())
			$this->getPage()->getCallbackClient()->setValue($this, $value);
	}

	/**
	 * Raises the callback event. This method is required by {@link
	 * ICallbackEventHandler} interface.
	 * This method is mainly used by framework and control developers.
	 * @param TCallbackEventParameter the event parameter
	 */
 	public function raiseCallbackEvent($param)
	{
		$this->onCallback($param);
	}

	/**
	 * This method is invoked when a callback is requested. The method raises
	 * 'OnCallback' event to fire up the event handlers. If you override this
	 * method, be sure to call the parent implementation so that the event
	 * handler can be invoked.
	 * @param TCallbackEventParameter event parameter to be passed to the event handlers
	 */
	public function onCallback($param)
	{
		$this->raiseEvent('OnCallback', $this, $param);
	}

	/**
	 * Gets the name of the javascript class responsible for performing postback for this control.
	 * This method overrides the parent implementation.
	 * @return string the javascript class name
	 */
	protected function getClientClassName()
	{
		return 'Prado.WebUI.TActiveHiddenField';
	}

	/**
	 * Override parent implementation, no javascript is rendered here instead
	 * the javascript required for active control is registered in {@link addAttributesToRender}.
	 */
	protected function renderClientControlScript($writer)
	{
	}

	/**
	 * 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());
	}
}