9 files changed, 936 insertions, 10 deletions
diff --git a/framework/Web/UI/ActiveControls/TActiveControl.php b/framework/Web/UI/ActiveControls/TActiveControl.php
new file mode 100644
index 00000000..d289bab9
--- /dev/null
+++ b/framework/Web/UI/ActiveControls/TActiveControl.php
@@ -0,0 +1,23 @@
+<?php
+
+/*
+ * Created on 25/04/2006
+ */
+
+class TActiveControl extends TControl implements ICallbackEventHandler, IActiveControl
+{	
+	public function __construct()
+	{
+		parent::__construct();
+		$this->setAdapter(new TActiveControlAdapter($this));
+	}
+
+	public function raiseCallbackEvent($param)
+	{
+		var_dump($param);
+		$client = $this->getPage()->getCallbackClient();
+		$client->hide($this);
+	}
+} 
+
+?>
diff --git a/framework/Web/UI/ActiveControls/TActiveControlAdapter.php b/framework/Web/UI/ActiveControls/TActiveControlAdapter.php
new file mode 100644
index 00000000..187b2cac
--- /dev/null
+++ b/framework/Web/UI/ActiveControls/TActiveControlAdapter.php
@@ -0,0 +1,25 @@
+<?php
+/*
+ * Created on 29/04/2006
+ */
+
+class TActiveControlAdapter extends TControlAdapter
+{
+	private static $_renderedPosts = false;
+	
+	/**
+	 * Render the callback request post data loaders once only.
+	 */
+	public function render($writer)
+	{
+		if(!self::$_renderedPosts)
+		{
+			$options = TJavascript::encode($this->getPage()->getPostDataLoaders(),false);
+			$script = "Prado.Callback.PostDataLoaders.concat({$options});";
+			$this->getPage()->getClientScript()->registerEndScript(get_class($this), $script);
+			self::$_renderedPosts = true;
+		}
+		parent::render($writer);
+	}	
+} 
+?>
diff --git a/framework/Web/UI/ActiveControls/TActivePageAdapter.php b/framework/Web/UI/ActiveControls/TActivePageAdapter.php
new file mode 100644
index 00000000..ab042d54
--- /dev/null
+++ b/framework/Web/UI/ActiveControls/TActivePageAdapter.php
@@ -0,0 +1,219 @@
+<?php
+/**
+ * TActivePageAdapter class file
+ *
+ * @author Wei Zhuo <weizhuo[at]gamil[dot]com>
+ * @link http://www.pradosoft.com/
+ * @copyright Copyright &copy; 2005 PradoSoft
+ * @license http://www.pradosoft.com/license/
+ * @version $Revision: $  $Date: $
+ * @package System.Web.UI.ActiveControls
+ */
+ 
+/**
+ * TActivePageAdapter class.
+ * 
+ * Callback request page handler.
+ * 
+ * @author Wei Zhuo <weizhuo[at]gamil[dot]com>
+ * @version $Revision: $  $Date: $
+ * @package System.Web.UI.ActiveControls
+ * @since 3.0
+ */
+class TActivePageAdapter extends TControlAdapter
+{	
+	/**
+	 * @var ICallbackEventHandler callback event handler. 
+	 */
+	private $_callbackEventTarget;
+	/**
+	 * @var mixed callback event parameter.
+	 */
+	private $_callbackEventParameter;
+	/**
+	 * @var TCallbackClientScript callback client script handler
+	 */
+	private $_callbackClient;
+	/**
+	 * @var TCallbackResponse callback response handler.
+	 */
+	private $_callbackResponse;
+	
+	private $_callbackEventResult;
+	 
+	/**
+	 * Constructor, trap errors and exception to let the callback response
+	 * handle them.
+	 */
+	public function __construct(TPage $control)
+	{
+		parent::__construct($control);
+		$this->trapCallbackErrorsExceptions();
+	}
+
+	/**
+	 * Process the callback request.
+	 */
+	public function processCallbackEvent($writer)
+	{
+		Prado::trace("ActivePage raiseCallbackEvent()",'System.Web.UI.ActiveControls.TActivePageAdapter');
+		$this->raiseCallbackEvent();
+	}
+	
+	protected function trapCallbackErrorsExceptions()
+	{
+		//TODO: How to trap the errors and exceptions and return them
+		// as part of the response.
+	}
+	
+	public function renderCallbackResponse($writer)
+	{
+		Prado::trace("ActivePage renderCallbackResponse()",'System.Web.UI.ActiveControls.TActivePageAdapter');
+		$this->renderResponse($writer);
+	}	
+	
+	protected function renderResponse($writer)
+	{
+		//var_dump(getallheaders());
+		//TODO: How to render the response, it will contain 3 pieces of data
+		// 1) The arbituary data returned to the client-side callback handler
+		// 2) client-side function call statements
+		// 3) Content body, which may need to be partitioned
+		
+		/*
+		$response = $this->getCallbackResponseHandler();
+		$response->writeClientScriptResponse($this->getCallbackClientHandler());
+		$response->writeResponseData($this->getCallbackEventResult());
+		$response->flush();
+		*/
+	}
+	
+	/**
+	 * Trys to find the callback event handler and raise its callback event.
+	 * @throws TInvalidCallbackRequestException if call back target is not
+	 * found.
+	 * @throws TInvalidCallbackHandlerException if the requested target does not
+	 * implement ICallbackEventHandler.
+	 */
+	private function raiseCallbackEvent()
+	{
+		 if(($callbackHandler=$this->getCallbackEventTarget())!==null)
+		 {
+			if($callbackHandler instanceof ICallbackEventHandler)
+				$callbackHandler->raiseCallbackEvent($this->getCallbackEventParameter());
+			else
+				throw new TInvalidCallbackHandlerException($callbackHandler->getUniqueID());
+		 }
+		 else
+		 {
+		 	$target = $this->getRequest()->itemAt(TPage::FIELD_CALLBACK_TARGET);
+		 	throw new TInvalidCallbackRequestException($target);
+		 }
+	}
+	
+	/**
+	 * @return mixed callback event result.
+	 */
+	public function getCallbackEventResult()
+	{
+		return $this->_callbackEventResult->getResult();
+	}
+	
+	/**
+	 * @return TControl the control responsible for the current callback event,
+	 * null if nonexistent
+	 */
+	public function getCallbackEventTarget()
+	{
+		if($this->_callbackEventTarget===null)
+		{
+			$eventTarget=$this->getRequest()->itemAt(TPage::FIELD_CALLBACK_TARGET);
+			if(!empty($eventTarget))
+				$this->_callbackEventTarget=$this->getPage()->findControl($eventTarget);
+		}
+		return $this->_callbackEventTarget;
+	}
+
+	/**
+	 * Registers a control to raise callback event in the current request.
+	 * @param TControl control registered to raise callback event.
+	 */
+	public function setCallbackEventTarget(TControl $control)
+	{
+		$this->_callbackEventTarget=$control;
+	}
+
+	/**
+	 * Callback parameter is decoded assuming JSON encoding. 
+	 * @return string postback event parameter
+	 */
+	public function getCallbackEventParameter()
+	{
+		if($this->_callbackEventParameter===null)
+		{
+			$param = $this->getRequest()->itemAt(TPage::FIELD_CALLBACK_PARAMETER);
+			if(strlen($param) > 0)
+				$this->_callbackEventParameter=TJavascript::jsonDecode((string)$param);
+			var_dump($param);
+		}
+		return $this->_callbackEventParameter;
+	}
+	
+	/**
+	 * @param mixed postback event parameter
+	 */
+	public function setCallbackEventParameter($value)
+	{
+		$this->_callbackEventParameter=$value;
+	}
+	
+	/**
+	 * Gets the callback client script handler that allows javascript functions
+	 * to be executed during the callback response. 
+	 * @return TCallbackClientScript callback client handler.
+	 */
+	public function getCallbackClientHandler()
+	{
+		if(is_null($this->_callbackClient))
+			$this->_callbackClient = new TCallbackClientScript;
+		return $this->_callbackClient;
+	}
+	
+	/**
+	 * @param TCallbackClientScript new callback client handler.
+	 */
+	public function setCallbackClientHandler($handler)
+	{
+		$this->_callbackClient = $handler;
+	}
+	
+	/**
+	 * Gets the callback response handler.
+	 * @return TCallbackResponse callback response
+	 */
+	public function getCallbackResponseHandler()
+	{
+		if(is_null($this->_callbackResponse))
+			$this->_callbackResponse = new TCallbackResponse;
+		return $this->_callbackResponse;
+	}
+	
+	/**
+	 * @param TCallbackResponse new callback response handler.
+	 */
+	public function setCallbackResponseHandler($handler)
+	{
+		$this->_callbackResponse = $handler;
+	}
+}
+
+class TInvalidCallbackHandlerException extends TException
+{
+	
+} 
+
+class TInvalidCallbackRequestException extends TException
+{
+}
+
+?>
diff --git a/framework/Web/UI/ActiveControls/TCallbackClientScript.php b/framework/Web/UI/ActiveControls/TCallbackClientScript.php
new file mode 100644
index 00000000..550c88b5
--- /dev/null
+++ b/framework/Web/UI/ActiveControls/TCallbackClientScript.php
@@ -0,0 +1,485 @@
+<?php
+/**
+ * TCallbackClientScript class file
+ *
+ * @author Wei Zhuo <weizhuo[at]gamil[dot]com>
+ * @link http://www.pradosoft.com/
+ * @copyright Copyright &copy; 2005 PradoSoft
+ * @license http://www.pradosoft.com/license/
+ * @version $Revision: $  $Date: $
+ * @package System.Web.UI.ActiveControls
+ */
+ 
+/**
+ * TCallbackClientScript class.
+ * 
+ * The TCallbackClientScript class provides corresponding methods that can be
+ * executed on the client-side (i.e. the browser client that is viewing
+ * the page) during a callback response.
+ * 
+ * The avaiable methods includes setting/clicking input elements, changing Css
+ * styles, hiding/showing elements, and adding visual effects to elements on the
+ * page. The client-side methods can be access through the CallbackClient
+ * property available in TPage.
+ * 
+ * For example, to hide "$myTextBox" element during callback response, do
+ * <code> 		
+ * $this->getPage()->getCallbackClient()->hide($myTextBox);
+ * </code>
+ * 
+ * @author Wei Zhuo <weizhuo[at]gamil[dot]com>
+ * @version $Revision: $  $Date: $
+ * @package System.Web.UI.ActiveControls
+ * @since 3.0
+ */ 
+class TCallbackClientScript 
+{
+	/**
+	 * @var TList list of client functions to execute.
+	 */
+	private $_actions;
+	
+	/**
+	 * Constructor.
+	 */
+	public function __construct()
+	{
+		$this->_actions = new TList;
+	}
+
+	/**
+	 * @return array list of client function to be executed during callback
+	 * response.
+	 */
+	public function getClientFunctionsToExecute()
+	{
+		return $this->_actions;
+	}
+	
+	/**
+	 * Executes a client-side statement.
+	 * @param string javascript function name
+	 * @param array list of arguments for the function
+	 */
+	public function callClientFunction($function, $params=null)
+	{
+		if(!is_array($params) && $params !== null) 
+			$params = array($params);
+		else
+			$params = array();
+			
+		if(count($params) > 0)
+		{
+			if($params[0] instanceof TControl)
+				$params[0] = $params[0]->getID();
+		}
+		$this->_actions->add(array($function => $params));
+	}
+
+	/**
+	 * Client script to set the value of a particular input element.
+	 * @param TControl|string control element to set the new value
+	 * @param string new value
+	 */
+	public function setValue($input, $text)
+	{
+		$this->callClientFunction('Prado.Element.setValue', array($input, $text));
+	}
+
+	/**
+	 * Client script to select/clear/check a drop down list, check box list, 
+	 * or radio button list.
+	 * The second parameter determines the selection method. Valid methods are
+	 *  - <b>Value</b>, select or check by value
+	 *  - <b>Index</b>, select or check by list index (zero based index)
+	 *  - <b>All</b>, selects or checks all in the list
+	 *  - <b>Clear</b>, clears or selections or checks in the list
+	 *  - <b>Invert</b>, inverts the current selection or checks.
+	 * @param TControl|string list control
+	 * @param string selection method
+	 * @param string|int the value or index to select/check.
+	 */
+	public function select($listControl, $method="Value", $valueOrIndex=null)
+	{
+		$this->callClientFunction('Prado.Element.select', array($listControl, $method, $valueOrIndex));
+	}		
+
+	/**
+	 * Client script to click on an element. <b>This client-side function
+	 * is unpredictable.</b>
+	 * @param TControl|string control element or element id
+	 */
+	public function click($control)
+	{
+		$this->callClientFunction('Prado.Element.click', $control);
+	}
+
+	/**
+	 * Client script to check or uncheck a checkbox or radio button.
+	 * @param TControl|string control element or element id
+	 * @param boolean check or uncheck the checkbox or radio button.
+	 */
+	public function check($checkbox, $checked=true)
+	{
+		$this->select($checkbox, "Value", $checked);
+	}
+
+	/**
+	 * Sets the attribute of a particular control. 
+	 * @param TControl|string control element or element id
+	 * @param string attribute name
+	 * @param string attribute value
+	 */
+	public function setAttribute($control, $name, $value)
+	{
+		$this->callClientFunction('Prado.Element.setAttribute',array($control, $name, $value));
+	}
+
+	/**
+	 * Sets the options of a select input element.
+	 * @param TControl|string control element or element id
+	 * @param TCollection a list of new options
+	 */
+	public function setOptions($control, $items)
+	{
+		$options = array();
+		foreach($items as $item)
+			$options[] = array($item->getText(),$item->getValue());
+		$this->callClientFunction('Prado.Element.setOptions', array($control, $options));
+	}
+	
+	/**
+	 * Shows an element by changing its CSS display style as empty.
+	 * @param TControl|string control element or element id 
+	 */
+	public function show($element)
+	{
+		$this->callClientFunction('Element.show', $element);
+	}
+
+	/**
+	 * Hides an element by changing its CSS display style to "none".
+	 * @param TControl|string control element or element id 
+	 */
+	public function hide($element)
+	{
+		$this->callClientFunction('Element.hide', $element);
+	}
+
+	/**
+	 * Toggles the visibility of the element.
+	 * @param TControl|string control element or element id 
+	 */
+	public function toggle($element)
+	{
+		$this->callClientFunction('Element.toggle', $element);
+	}
+
+	/**
+	 * Removes an element from the HTML page.
+	 * @param TControl|string control element or element id
+	 */
+	public function remove($element)
+	{
+		$this->callClientFunction('Element.remove', $element);
+	}
+
+	/**
+	 * Update the element's innerHTML with new content.
+	 * @param TControl|string control element or element id
+	 * @param TControl|string new HTML content, if content is of a TControl, the
+	 * controls render method is called.
+	 */
+	public function update($element, $innerHTML)
+	{
+		if($innerHTML instanceof TControl)
+			$innerHTML = $innerHTML->render();
+		$this->callClientFunction('Element.update', array($element, $innerHTML));
+	}
+
+	/**
+	 * Replace the innerHTML of a content with fragements of the response body.
+	 * @param TControl|string control element or element id
+	 */
+	public function replaceContent($element)
+	{
+		$this->callClientFunction('Prado.Element.replaceContent', $element);
+	}
+
+	/**
+	 * Add a Css class name to the element.
+	 * @param TControl|string control element or element id
+	 * @param string CssClass name to add.
+	 */
+	public function addCssClass($element, $cssClass)
+	{
+		$this->callClientFunction('Element.addClassName', array($element, $cssClass));
+	}
+
+	/**
+	 * Remove a Css class name from the element.
+	 * @param TControl|string control element or element id
+	 * @param string CssClass name to remove.
+	 */
+	public function removeCssClass($element, $cssClass)
+	{
+		$this->callClientFunction('Element.removeClassName', array($element, $cssClass));
+	}
+
+	/**
+	 * Sets the CssClass of an element.
+	 * @param TControl|string control element or element id
+	 * @param string new CssClass name for the element.
+	 */
+	public function setCssClass($element, $cssClass)
+	{
+		$this->callClientFunction('Prado.Element.CssClass.set', array($element, $cssClass));
+	}
+
+	/**
+	 * Scroll the top of the browser viewing area to the location of the
+	 * element.
+	 * @param TControl|string control element or element id
+	 */
+	public function scrollTo($element)
+	{
+		$this->callClientFunction('Element.scrollTo', $element);
+	}
+
+	/**
+	 * Sets the style of element. The style must be a key-value array where the
+	 * key is the style property and the value is the style value.
+	 * @param TControl|string control element or element id
+	 * @param array list of key-value pairs as style property and style value.
+	 */
+	public function setStyle($element, $styles)
+	{
+		$this->callClientFunction('Element.setStyle', array($element, $styles));
+	}
+
+	/**
+	 * Insert a HTML fragement after the element.
+	 * @param TControl|string control element or element id
+	 * @param TControl|string HTML fragement, otherwise if TControl, its render
+	 * method will be called.
+	 */
+	public function insertAfter($element, $innerHTML)
+	{
+		if($innerHTML instanceof TControl)
+			$innerHTML = $innerHTML->render();
+		$this->callClientFunction('Prado.Element.Insert.After', array($element, $innerHTML));
+	}
+
+	/**
+	 * Insert a HTML fragement before the element.
+	 * @param TControl|string control element or element id
+	 * @param TControl|string HTML fragement, otherwise if TControl, its render
+	 * method will be called.
+	 */	
+	public function insertBefore($element, $innerHTML)
+	{
+		if($innerHTML instanceof TControl)
+			$innerHTML = $innerHTML->render();
+		$this->callClientFunction('Prado.Element.Insert.Before', array($element, $innerHTML));
+	}
+
+	/**
+	 * Insert a HTML fragement below the element.
+	 * @param TControl|string control element or element id
+	 * @param TControl|string HTML fragement, otherwise if TControl, its render
+	 * method will be called.
+	 */
+	public function insertBelow($element, $innerHTML)
+	{
+		if($innerHTML instanceof TControl)
+			$innerHTML = $innerHTML->render();
+		$this->callClientFunction('Prado.Element.Insert.Below', array($element, $innerHTML));
+	}
+
+	/**
+	 * Insert a HTML fragement above the element.
+	 * @param TControl|string control element or element id
+	 * @param TControl|string HTML fragement, otherwise if TControl, its render
+	 * method will be called.
+	 */
+	public function insertAbove($element, $innerHTML)
+	{
+		if($innerHTML instanceof TControl)
+			$innerHTML = $innerHTML->render();
+		$this->callClientFunction('Prado.Element.Insert.Above', array($element, $innerHTML));
+	}	
+
+	/**
+	 * Add a visual effect the element.
+	 * @param string visual effect function name.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options.
+	 */
+	public function visualEffect($type, $element, $options=null)
+	{
+		$this->callClientFunction($type, is_array($options) ? array($element, $options) : $element);
+	}
+
+	/**
+	 * Visual Effect: Gradually make the element appear.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */
+	public function appear($element, $options=null)
+	{
+		$this->visualEffect('Effect.Appear', $element, $options);
+	}
+
+	/**
+	 * Visual Effect: Blind down.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */
+	public function blindDown($element, $options=null)
+	{
+		$this->visualEffect('Effect.BlindDown', $element, $options);
+	}
+
+	/**
+	 * Visual Effect: Blind up.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */
+	public function blindUp($element, $options=null)
+	{
+		$this->visualEffect('Effect.BlindUp', $element, $options);
+			
+	}
+
+	/**
+	 * Visual Effect: Drop out.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */
+	public function dropOut($element, $options=null)
+	{
+		$this->visualEffect('Effect.DropOut', $element, $options);
+	}
+	
+	/**
+	 * Visual Effect: Gradually fade the element.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */
+	public function fade($element, $options=null)
+	{
+		$this->visualEffect('Effect.Fade', $element, $options);
+	}
+	
+	/**
+	 * Visual Effect: Fold.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */
+	public function fold($element, $options = null)
+	{
+		$this->visualEffect('Effect.Fold', $element, $options);
+	}
+
+	/**
+	 * Visual Effect: Gradually make an element grow to a predetermined size.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */
+	public function grow($element, $options=null)
+	{
+		$this->visualEffect('Effect.Grow', $element, $options);
+	}
+
+	/**
+	 * Visual Effect: Gradually grow and fade the element.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */
+	public function puff($element, $options=null)
+	{
+		$this->visualEffect('Effect.Puff', $element, $options);
+	}
+
+	/**
+	 * Visual Effect: Pulsate.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */	
+	public function pulsate($element, $options=null)
+	{
+		$this->visualEffect('Effect.Pulsate', $element, $options);
+	}
+
+	/**
+	 * Visual Effect: Shake the element.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */
+	public function shake($element, $options=null)
+	{
+		$this->visualEffect('Effect.Shake', $element, $options);
+	}
+
+	/**
+	 * Visual Effect: Shrink the element.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */
+	public function shrink($element, $options=null)
+	{
+		$this->visualEffect('Effect.Shrink', $element, $options);
+	}
+
+	/**
+	 * Visual Effect: Slide down.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */
+	public function slideDown($element, $options=null)
+	{
+		$this->visualEffect('Effect.SlideDown', $element, $options);
+	}
+
+	/**
+	 * Visual Effect: Side up.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */
+	public function slideUp($element, $options=null)
+	{
+		$this->visualEffect('Effect.SlideUp', $element, $options);
+	}
+	
+	/**
+	 * Visual Effect: Squish the element.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */
+	public function squish($element, $options=null)
+	{
+		$this->visualEffect('Effect.Squish', $element, $options);
+	}
+	
+	/**
+	 * Visual Effect: Switch Off effect.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */
+	public function switchOff($element, $options=null)
+	{
+		$this->visualEffect('Effect.SwitchOff', $element, $options);
+	}
+
+	/**
+	 * Visual Effect: High light the element for about 2 seconds.
+	 * @param TControl|string control element or element id
+	 * @param array visual effect key-value pair options. 
+	 */
+	public function highlight($element, $options=null)
+	{
+		$this->visualEffect('Effect.Highlight', $element, $options);
+	}
+}
+
+?>
diff --git a/framework/Web/UI/ActiveControls/TCallbackResponse.php b/framework/Web/UI/ActiveControls/TCallbackResponse.php
new file mode 100644
index 00000000..bda4e916
--- /dev/null
+++ b/framework/Web/UI/ActiveControls/TCallbackResponse.php
@@ -0,0 +1,20 @@
+<?php
+/*
+ * Created on 29/04/2006
+ */
+
+// See TActivePageAdapter::renderResponse()
+//TODO: How to render the response, it will contain 3 pieces of data
+// 1) The arbituary data returned to the client-side callback handler
+// 2) client-side function call statements
+// 3) Content body, which may need to be partitioned
+
+class TCallbackResponse extends THttpResponse
+{
+	const CALLBACK_DATA_HEADER = 'X-PRADO-DATA';
+	const CALLBACK_ACTION_HEADER = 'X-PRADO-ACTIONS';	
+}
+
+
+
+?>
diff --git a/framework/Web/UI/TControl.php b/framework/Web/UI/TControl.php
index 1f1d6c4d..1b5394ba 100644
--- a/framework/Web/UI/TControl.php
+++ b/framework/Web/UI/TControl.php
@@ -867,7 +867,7 @@ class TControl extends TApplicationComponent implements IRenderable, IBindable
 	 * Do not call this method directly. Instead, call {@link ensureChildControls}
 	 * to ensure child controls are created only once.
 	 */
-	protected function createChildControls()
+	public function createChildControls()
 	{
 	}
 
@@ -1215,6 +1215,9 @@ class TControl extends TApplicationComponent implements IRenderable, IBindable
 	protected function preRenderRecursive()
 	{
 		$this->autoDataBindProperties();
+		
+		if($this->getEnabled() && $this instanceof IPostBackDataHandler)
+			$this->getPage()->registerPostDataLoader($this);
 
 		if($this->getVisible(false))
 		{
diff --git a/framework/Web/UI/TPage.php b/framework/Web/UI/TPage.php
index e34101d9..31c80320 100644
--- a/framework/Web/UI/TPage.php
+++ b/framework/Web/UI/TPage.php
@@ -36,7 +36,7 @@ class TPage extends TTemplateControl
 	const FIELD_PAGESTATE='PRADO_PAGESTATE';
 	const FIELD_CALLBACK_TARGET='PRADO_CALLBACK_TARGET';
 	const FIELD_CALLBACK_PARAMETER='PRADO_CALLBACK_PARAMETER';
-	const FIELD_CALLBACK_ID='PRADO_CALLBACK_ID';
+//	const FIELD_CALLBACK_ID='PRADO_CALLBACK_ID';
 	/**
 	 * @var array system post fields
 	 */
@@ -46,8 +46,8 @@ class TPage extends TTemplateControl
 		'PRADO_LASTFOCUS'=>true,
 		'PRADO_PAGESTATE'=>true,
 		'PRADO_CALLBACK_TARGET'=>true,
-		'PRADO_CALLBACK_PARAMETER'=>true,
-		'PRADO_CALLBACK_ID'=>true
+		'PRADO_CALLBACK_PARAMETER'=>true
+		//'PRADO_CALLBACK_ID'=>true
 	);
 	/**
 	 * @var TForm form instance
@@ -149,7 +149,11 @@ class TPage extends TTemplateControl
 	 * @var string state string to be stored on the client side
 	 */
 	private $_clientState='';
-
+	/**
+	 * @var array post data loader IDs.
+	 */
+	private $_postDataLoaders=array();
+	
 	/**
 	 * Constructor.
 	 * Sets the page object to itself.
@@ -259,11 +263,159 @@ class TPage extends TTemplateControl
 		$this->unloadRecursive();
 	}
 
+	/**
+	 * Sets Adapter to TActivePageAdapter and calls apter to process the
+	 * callback request.
+	 */
 	protected function processCallbackRequest($writer)
 	{
+		$this->setAdapter(new TActivePageAdapter($this));
+		
+		Prado::trace("Page onPreInit()",'System.Web.UI.TPage');
+		$this->onPreInit(null);
+
+		Prado::trace("Page initRecursive()",'System.Web.UI.TPage');
+		$this->initRecursive();
+
+		Prado::trace("Page onInitComplete()",'System.Web.UI.TPage');
+		$this->onInitComplete(null);
+
+		$this->_restPostData=new TMap;
+		Prado::trace("Page loadPageState()",'System.Web.UI.TPage');
+		$this->loadPageState();
+		Prado::trace("Page processPostData()",'System.Web.UI.TPage');
+		$this->processPostData($this->_postData,true);
+		Prado::trace("Page onPreLoad()",'System.Web.UI.TPage');
+		$this->onPreLoad(null);
+		Prado::trace("Page loadRecursive()",'System.Web.UI.TPage');
+		$this->loadRecursive();
+		Prado::trace("Page processPostData()",'System.Web.UI.TPage');
+		$this->processPostData($this->_restPostData,false);
+		Prado::trace("Page raiseChangedEvents()",'System.Web.UI.TPage');
+		$this->raiseChangedEvents();
+
+		$this->getAdapter()->processCallbackEvent($writer); 
+
+/*		
+		Prado::trace("Page raisePostBackEvent()",'System.Web.UI.TPage');
+		$this->raisePostBackEvent();
+*/		
+		Prado::trace("Page onLoadComplete()",'System.Web.UI.TPage');
+		$this->onLoadComplete(null);
+
+		Prado::trace("Page preRenderRecursive()",'System.Web.UI.TPage');
+		$this->preRenderRecursive();
+		Prado::trace("Page onPreRenderComplete()",'System.Web.UI.TPage');
+		$this->onPreRenderComplete(null);
+
+/*		Prado::trace("Page savePageState()",'System.Web.UI.TPage');
+		$this->savePageState();
+		Prado::trace("Page onSaveStateComplete()",'System.Web.UI.TPage');
+		$this->onSaveStateComplete(null);
+
+		Prado::trace("Page renderControl()",'System.Web.UI.TPage');
+		$this->renderControl($writer);
+*/
+		$this->getAdapter()->renderCallbackResponse($writer);
+		
+		Prado::trace("Page unloadRecursive()",'System.Web.UI.TPage');
+		$this->unloadRecursive();			
+	}
+	
+	/**
+	 * Gets the callback response handler that permits changing the callback
+	 * response headers and contents.
+	 * @return TCallbackResponse callback response handler.
+	 */
+	public function getCallbackResponse()
+	{
+		return $this->getAdapter()->getCallbackResponseHandler();
+	}
+	
+	/**
+	 * Set a new callback respond handler.
+	 * @param TCallbackResponse a different callback response handler.
+	 */
+	public function setCallbackResponse($responder)
+	{
+		$this->getAdapter()->setCallbackResponseHandler($responder);
+	}
+	
+	/**
+	 * Gets the callback client script handler that allows javascript functions
+	 * to be executed during the callback response. 
+	 * @return TCallbackClientScript interface to client-side javascript code.
+	 */
+	public function getCallbackClient()
+	{
+		return $this->getAdapter()->getCallbackClientHandler();
+	}
+	
+	/**
+	 * Set a new callback client handler.
+	 * @param TCallbackClientScript new callback client script handler.
+	 */
+	public function setCallbackClient($client)
+	{
+		$this->getAdapter()->setCallbackClientHandler($client);
+	}
+	
+	/**
+	 * @return TControl the control responsible for the current callback event,
+	 * null if nonexistent
+	 */
+	public function getCallbackEventTarget()
+	{
+		return $this->getAdapter()->getCallbackEventTarget();
 	}
 
 	/**
+	 * Registers a control to raise callback event in the current request.
+	 * @param TControl control registered to raise callback event.
+	 */
+	public function setCallbackEventTarget(TControl $control)
+	{
+		$this->getAdapter()->setCallbackEventTarget($control);
+	}
+
+	/**
+	 * Callback parameter is decoded assuming JSON encoding. 
+	 * @return string callback event parameter
+	 */
+	public function getCallbackEventParameter()
+	{
+		return $this->getAdapter()->getCallbackEventParameter();
+	}
+	
+	/**
+	 * @param mixed callback event parameter
+	 */
+	public function setCallbackEventParameter($value)
+	{
+		$this->getAdapter()->setCallbackEventParameter($value);
+	}
+	
+	/**
+	 * Register post data loaders for Callback to collect post data.
+	 * This method should only be called by framework developers.
+	 * @param TControl control that requires post data.
+	 * @see TControl::preRenderRecursive();
+	 */
+	public function registerPostDataLoader($control)
+	{
+		$this->_postDataLoaders[] = $control->getUniqueID();
+	}
+	
+	/**
+	 * Get a list of IDs of controls that are enabled and require post data.
+	 * @return array list of IDs implementing IPostBackDataHandler
+	 */
+	public function getPostDataLoaders()
+	{
+		return $this->_postDataLoaders;
+	}
+	
+	/**
 	 * @return TForm the form on the page
 	 */
 	public function getForm()
@@ -541,12 +693,11 @@ class TPage extends TTemplateControl
 	}
 
 	/**
-	 * TBD
 	 * @return boolean whether this is a callback request
 	 */
 	public function getIsCallback()
 	{
-		return false;
+		return $this->getIsPostBack() && $this->getRequest()->contains(self::FIELD_CALLBACK_TARGET);
 	}
 
 	/**
diff --git a/framework/Web/UI/TTemplateControl.php b/framework/Web/UI/TTemplateControl.php
index 971f0288..f18678f1 100644
--- a/framework/Web/UI/TTemplateControl.php
+++ b/framework/Web/UI/TTemplateControl.php
@@ -123,7 +123,7 @@ class TTemplateControl extends TControl implements INamingContainer
 	 * This method is overriden to load and instantiate control template.
 	 * This method should only be used by framework and control developers.
 	 */
-	protected function createChildControls()
+	public function createChildControls()
 	{
 		if($tpl=$this->getTemplate(true))
 		{
diff --git a/framework/Web/UI/WebControls/TWizard.php b/framework/Web/UI/WebControls/TWizard.php
index 9a2c4ce6..20e27f2b 100644
--- a/framework/Web/UI/WebControls/TWizard.php
+++ b/framework/Web/UI/WebControls/TWizard.php
@@ -1005,7 +1005,7 @@ class TWizard extends TWebControl implements INamingContainer
 	/**
 	 * Creates child controls within the wizard
 	 */
-	protected function createChildControls()
+	public function createChildControls()
 	{
 		$this->reset();
 		$this->createSideBar();
@@ -1650,7 +1650,7 @@ class TTemplatedWizardStep extends TWizardStep implements INamingContainer
 	 * Creates child controls.
 	 * This method mainly instantiates the content template, if any.
 	 */
-	protected function createChildControls()
+	public function createChildControls()
 	{
 		$this->getControls()->clear();
 		if($this->_contentTemplate)