Added TReCaptcha2 and wrote doc; fix #560

12 files changed, 695 insertions, 1 deletions

diff --git a/HISTORY b/HISTORY
index ca492cd6..042e9c2b 100644
--- a/HISTORY
+++ b/HISTORY
@@ -13,6 +13,7 @@ ENH: Issue #569 - Improved TJavascriptLogger / browser console logging of errors
 ENH: Applied some misc optimizations to class serialization (ctrlaltca)
 ENH: Intercept fatal errors using register_shutdown_function (ctrlaltca)
 ENH: Activecontrols: avoid updating client side if the value didn't change (ctrlaltca)
+ENH: Added TReCaptcha2 / TReCaptcha2Validator (camilohaze)
 BUG: Fix callback update of TActiveCheckBoxList when initially empty (LCSKJ)
 
 Version 3.3.0 February 15, 2016
diff --git a/demos/quickstart/protected/pages/Controls/ReCaptcha.page b/demos/quickstart/protected/pages/Controls/ReCaptcha.page
new file mode 100644
index 00000000..0735bb9e
--- /dev/null
+++ b/demos/quickstart/protected/pages/Controls/ReCaptcha.page
@@ -0,0 +1,37 @@
+<com:TContent ID="body" >
+
+<h1>TReCaptcha</h1>
+<com:DocLink ClassPath="System.Web.UI.WebControls.TReCaptcha" />
+
+<p class="block-content">
+<tt>TReCaptcha</tt> displays a <a href="https://www.google.com/recaptcha">reCAPTCHA v1</a> that can be used to determine if the input is entered by a real user instead of some program. It can also prevent multiple submits of the same form either by accident, or on purpose (ie. spamming).
+</p>
+
+<p class="block-content">
+The reCAPTCHA to solve (a string consisting of two separate words) displayed is automatically generated by the reCAPTCHA system at recaptcha.net. However, in order to use the services of the site you will need to register and get a public and a private API key pair, and  supply those to the reCAPTCHA control through setting the <tt>PrivateKey</tt> and <tt>PublicKey</tt> properties.
+</p>
+
+<p class="block-content">
+Currently the reCAPTCHA API supports only one reCAPTCHA field per page, so you MUST make sure that all your input is protected and validated by a single reCAPTCHA control. Placing more than one reCAPTCHA control on the page will lead to unpredictable results, and the user will most likely unable to solve any of them successfully.
+ </p>
+
+<p class="block-content">
+Upon postback, user input can be validated by calling <tt>validate()</tt>. The <tt>TReCaptchaValidator</tt> control can also be used to do validation, which provides server-side validation. Calling <tt>validate()</tt> will invalidate the token supplied, so all consecutive calls to the method - without solving a new captcha - will return false. Therefore if implementing a multi-stage input process, you must make sure that you call <tt>validate()</tt> only once, either at the end of the input process, or you store the result till the end of the processing.
+</p>
+
+<p class="block-content">
+The following template shows a typical use of TReCaptcha control:
+</p>
+
+<com:TTextHighlighter Language="prado" CssClass="source block-content">
+&lt;com:TReCaptcha ID="Captcha"
+   PublicKey="..."
+   PrivateKey="..."
+/>
+&lt;com:TReCaptchaValidator ControlToValidate="Captcha"
+    ErrorMessage="You are challenged!" />
+</com:TTextHighlighter>
+
+<com:RunBar PagePath="Controls.Samples.TReCaptcha.Home" />
+
+</com:TContent>
diff --git a/demos/quickstart/protected/pages/Controls/ReCaptcha2.page b/demos/quickstart/protected/pages/Controls/ReCaptcha2.page
new file mode 100644
index 00000000..dd87a22d
--- /dev/null
+++ b/demos/quickstart/protected/pages/Controls/ReCaptcha2.page
@@ -0,0 +1,37 @@
+<com:TContent ID="body" >
+
+<h1>TReCaptcha</h1>
+<com:DocLink ClassPath="System.Web.UI.WebControls.TReCaptcha" />
+
+<p class="block-content">
+<tt>TReCaptcha</tt> displays a <a href="https://www.google.com/recaptcha">reCAPTCHA v2</a> that can be used to determine if the input is entered by a real user instead of some program. It can also prevent multiple submits of the same form either by accident, or on purpose (ie. spamming).
+</p>
+
+<p class="block-content">
+The reCAPTCHA to solve (a string consisting of two separate words) displayed is automatically generated by the reCAPTCHA system at recaptcha.net. However, in order to use the services of the site you will need to register and get a public and a private API key pair, and  supply those to the reCAPTCHA control through setting the <tt>SecretKey</tt> and <tt>SiteKey</tt> properties.
+</p>
+
+<p class="block-content">
+Currently the reCAPTCHA API supports only one reCAPTCHA field per page, so you MUST make sure that all your input is protected and validated by a single reCAPTCHA control. Placing more than one reCAPTCHA control on the page will lead to unpredictable results, and the user will most likely unable to solve any of them successfully.
+ </p>
+
+<p class="block-content">
+Upon postback, user input can be validated by calling <tt>validate()</tt>. The <tt>TReCaptcha2Validator</tt> control can also be used to do validation, which provides server-side validation. Calling <tt>validate()</tt> will invalidate the token supplied, so all consecutive calls to the method - without solving a new captcha - will return false. Therefore if implementing a multi-stage input process, you must make sure that you call <tt>validate()</tt> only once, either at the end of the input process, or you store the result till the end of the processing.
+</p>
+
+<p class="block-content">
+The following template shows a typical use of TReCaptcha control:
+</p>
+
+<com:TTextHighlighter Language="prado" CssClass="source block-content">
+&lt;com:TReCaptcha2 ID="Captcha"
+   SiteKey="..."
+   SecretKey="..."
+/>
+&lt;com:TReCaptcha2Validator ControlToValidate="Captcha"
+    ErrorMessage="You are challenged!" />
+</com:TTextHighlighter>
+
+<com:RunBar PagePath="Controls.Samples.TReCaptcha2.Home" />
+
+</com:TContent>
diff --git a/demos/quickstart/protected/pages/Controls/Samples/TReCaptcha/Home.page b/demos/quickstart/protected/pages/Controls/Samples/TReCaptcha/Home.page
new file mode 100755
index 00000000..6a0188d6
--- /dev/null
+++ b/demos/quickstart/protected/pages/Controls/Samples/TReCaptcha/Home.page
@@ -0,0 +1,17 @@
+<com:TContent ID="body">
+<h1>TReCaptcha Samples</h1>
+
+<h2>Validating ReCAPTCHA v1</h2>
+
+Please note that this sample can't work unless you provide a valid private/public key to use the ReCAPTCHA service.
+
+<com:TReCaptcha ID="Captcha"
+   PublicKey="insert your public key here"
+   PrivateKey="insert your private key here"
+/>
+
+<com:TButton Id="SubmitButton" Text="Submit" OnClick="buttonClicked" />
+<com:TReCaptchaValidator ControlToValidate="Captcha"
+    ErrorMessage="You are challenged!" />
+
+</com:TContent>
diff --git a/demos/quickstart/protected/pages/Controls/Samples/TReCaptcha/Home.php b/demos/quickstart/protected/pages/Controls/Samples/TReCaptcha/Home.php
new file mode 100755
index 00000000..d99d2df2
--- /dev/null
+++ b/demos/quickstart/protected/pages/Controls/Samples/TReCaptcha/Home.php
@@ -0,0 +1,11 @@
+<?php
+
+class Home extends TPage
+{
+	public function buttonClicked($sender,$param)
+	{
+		if($this->IsValid)
+			$sender->Text="You passed!";
+	}
+}
+
diff --git a/demos/quickstart/protected/pages/Controls/Samples/TReCaptcha2/Home.page b/demos/quickstart/protected/pages/Controls/Samples/TReCaptcha2/Home.page
new file mode 100755
index 00000000..742fe496
--- /dev/null
+++ b/demos/quickstart/protected/pages/Controls/Samples/TReCaptcha2/Home.page
@@ -0,0 +1,17 @@
+<com:TContent ID="body">
+<h1>TReCaptcha Samples</h1>
+
+<h2>Validating ReCAPTCHA v2</h2>
+
+Please note that this sample can't work unless you provide a valid private/public key to use the ReCAPTCHA service.
+
+<com:TReCaptcha2 ID="Captcha"
+   SiteKey="insert your site key"
+   SecretKey="insert your secret key"
+/>
+
+<com:TActiveButton Id="SubmitButton" Text="Submit" OnCallback="buttonCallback" />
+<com:TReCaptcha2Validator ControlToValidate="Captcha"
+    ErrorMessage="You are challenged!" />
+
+</com:TContent>
diff --git a/demos/quickstart/protected/pages/Controls/Samples/TReCaptcha2/Home.php b/demos/quickstart/protected/pages/Controls/Samples/TReCaptcha2/Home.php
new file mode 100755
index 00000000..aedbb7dc
--- /dev/null
+++ b/demos/quickstart/protected/pages/Controls/Samples/TReCaptcha2/Home.php
@@ -0,0 +1,11 @@
+<?php
+
+class Home extends TPage
+{
+	public function buttonCallback($sender,$param)
+	{
+		if($this->IsValid)
+			$sender->Text="You passed!";
+	}
+}
+
diff --git a/demos/quickstart/protected/pages/Controls/Standard.page b/demos/quickstart/protected/pages/Controls/Standard.page
index 43fecfb3..508442ed 100755
--- a/demos/quickstart/protected/pages/Controls/Standard.page
+++ b/demos/quickstart/protected/pages/Controls/Standard.page
@@ -134,6 +134,14 @@
   </li>

 

   <li>

+  <a href="?page=Controls.ReCaptcha">TReCaptcha</a> displays a <a href="https://www.google.com/recaptcha">ReCaptcha v1</a> useful to detect if the user is a bot or an human.

+  </li>

+

+  <li>

+  <a href="?page=Controls.ReCaptcha2">TReCaptcha2</a> displays a <a href="https://www.google.com/recaptcha">ReCaptcha v2</a> useful to detect if the user is a bot or an human.

+  </li>

+

+  <li>

   <a href="?page=Controls.SafeHtml">TSafeHtml</a> displays its body content with assurance that the content contain no harmful code (such as <a href="?page=Advanced.Security">XSS</a>).

   </li>

 

diff --git a/framework/Web/Javascripts/source/prado/validator/validation3.js b/framework/Web/Javascripts/source/prado/validator/validation3.js
index 24466599..6dcf02e9 100644
--- a/framework/Web/Javascripts/source/prado/validator/validation3.js
+++ b/framework/Web/Javascripts/source/prado/validator/validation3.js
@@ -1239,6 +1239,8 @@ Prado.WebUI.TBaseValidator = jQuery.klass(Prado.WebUI.Control,
 			case 'TActiveCheckBox':
 			case 'TActiveRadioButton':
 				return value;
+            case 'TReCaptcha2':
+                return document.getElementById(this.options.ResponseFieldName).value;
 			default:
 				if(this.isListControlType())
 					return value;
@@ -1994,3 +1996,83 @@ Prado.WebUI.TReCaptchaValidator = jQuery.klass(Prado.WebUI.TBaseValidator,
 	}
 });
 
+/**
+ * Registry for TReCaptcha2 components
+ */
+Prado.WebUI.TReCaptcha2Instances = {};
+/**
+ * Render callback; called by google's js when loaded
+ */
+TReCaptcha2_onloadCallback = function()
+{
+	jQuery.each(Prado.WebUI.TReCaptcha2Instances, function(index, item) {
+    	item.build();
+	});
+}
+
+/**
+ * TReCaptcha2 client-side control.
+ *
+ * @class Prado.WebUI.TReCaptcha2
+ * @extends Prado.WebUI.Control
+ */
+Prado.WebUI.TReCaptcha2 = jQuery.klass(Prado.WebUI.Control,
+{
+    onInit: function(options)
+    {
+        for (key in options) { this[key] = options[key]; }
+        this.options['callback'] = jQuery.proxy(this.callback,this);
+        this.options['expired-callback'] = jQuery.proxy(this.callbackExpired,this);
+        
+        Prado.WebUI.TReCaptcha2Instances[this.element.id] = this;
+    },
+    build: function()
+    {
+       if (grecaptcha !== undefined) this.widgetId = grecaptcha.render(this.element, this.options);
+    },
+    callback: function(response)
+    {
+        var responseField = jQuery('#' + this.ID + ' textarea').attr('id');
+        var params = {
+            widgetId: this.widgetId,
+            response: response,
+            responseField: responseField,
+            onCallback: this.onCallback
+        };
+        var request = new Prado.CallbackRequest(this.EventTarget,this);
+        request.setCallbackParameter(params);
+        request.dispatch();
+    },
+    callbackExpired: function()
+    {
+        var responseField = jQuery('#' + this.ID + ' textarea').attr('id');
+        var params = {
+            responseField: responseField,
+            onCallbackExpired: this.onCallbackExpired
+        };
+        var request = new Prado.CallbackRequest(this.EventTarget,this);
+        request.setCallbackParameter(params);
+        request.dispatch();
+    }
+});
+
+/**
+ * TReCaptcha2Validator client-side control.
+ *
+ * @class Prado.WebUI.TReCaptcha2Validator
+ * @extends Prado.WebUI.TBaseValidator
+ */
+Prado.WebUI.TReCaptcha2Validator = jQuery.klass(Prado.WebUI.TBaseValidator,
+{
+    /**
+     * Evaluate validation state
+     * @function {boolean} ?
+     * @return True if the captcha has validate, False otherwise.
+     */
+    evaluateIsValid : function()
+    {
+        var a = this.getValidationValue();
+        var b = this.trim(this.options.InitialValue);
+        return(a != b);
+    }
+});
\ No newline at end of file
diff --git a/framework/Web/UI/WebControls/TReCaptcha2.php b/framework/Web/UI/WebControls/TReCaptcha2.php
new file mode 100644
index 00000000..ed3f9871
--- /dev/null
+++ b/framework/Web/UI/WebControls/TReCaptcha2.php
@@ -0,0 +1,363 @@
+<?php
+
+/**
+ * TReCaptcha2 class file
+ *
+ * @author Cristian Camilo Naranjo Valencia
+ * @link http://icolectiva.co
+ * @copyright Copyright &copy; 2005-2016 The PRADO Group
+ * @license https://github.com/pradosoft/prado/blob/master/COPYRIGHT
+ * @package System.Web.UI.WebControls
+ */
+
+Prado::using('System.Web.UI.ActiveControls.TCallbackEventParameter');
+Prado::using('System.Web.UI.ActiveControls.TActivePanel');
+
+/**
+ * TReCaptcha2 class.
+ *
+ * TReCaptcha2 displays a reCAPTCHA (a token displayed as an image) that can be used
+ * to determine if the input is entered by a real user instead of some program. It can
+ * also prevent multiple submits of the same form either by accident, or on purpose (ie. spamming).
+ *
+ * The reCAPTCHA to solve (a string consisting of two separate words) displayed is automatically
+ * generated by the reCAPTCHA system at recaptcha.net. However, in order to use the services
+ * of the site you will need to register and get a public and a private API key pair, and 
+ * supply those to the reCAPTCHA control through setting the {@link setSecretKey SecretKey} 
+ * and {@link setSiteKey SiteKey} properties. 
+ *
+ * Currently the reCAPTCHA API supports only one reCAPTCHA field per page, so you MUST make sure that all 
+ * your input is protected and validated by a single reCAPTCHA control. Placing more than one reCAPTCHA
+ * control on the page will lead to unpredictable results, and the user will most likely unable to solve 
+ * any of them successfully.
+ *
+ * Upon postback, user input can be validated by calling {@link validate()}.
+ * The {@link TReCaptcha2Validator} control can also be used to do validation, which provides
+ * server-side validation. Calling (@link validate()) will invalidate the token supplied, so all consecutive
+ * calls to the method - without solving a new captcha - will return false. Therefore if implementing a multi-stage
+ * input process, you must make sure that you call validate() only once, either at the end of the input process, or 
+ * you store the result till the end of the processing.
+ *
+ * The following template shows a typical use of TReCaptcha control:
+ * <code>
+ * <com:TReCaptcha2 ID="Captcha"
+ *                 SiteKey="..."
+ *                 SecretKey="..."
+ * />
+ * <com:TReCaptcha2Validator ControlToValidate="Captcha"
+ *                          ErrorMessage="You are challenged!" />
+ * </code>
+ *
+ * @author Cristian Camilo Naranjo Valencia
+ * @package System.Web.UI.WebControls
+ * @since 3.3.1
+ */
+
+class TReCaptcha2 extends TActivePanel implements ICallbackEventHandler, IValidatable
+{
+    const ChallengeFieldName = 'g-recaptcha-response';
+    private $_widgetId=0;
+    private $_isValid=true;
+
+    public function __construct()
+    {
+        parent::__construct();
+        $this->setAdapter(new TActiveControlAdapter($this));
+    }
+    public function getActiveControl()
+    {
+        return $this->getAdapter()->getBaseActiveControl();
+    }
+    public function getClientSide()
+    {
+        return $this->getAdapter()->getBaseActiveControl()->getClientSide();
+    }
+    public function getClientClassName()
+    {
+        return 'Prado.WebUI.TReCaptcha2';
+    }
+    public function getTagName()
+    {
+        return 'div';
+    }
+    /**
+     * Returns true if this control validated successfully. 
+     * Defaults to true.
+     * @return bool wether this control validated successfully.
+     */
+    public function getIsValid()
+    {
+        return $this->_isValid;
+    }
+    /**
+     * @param bool wether this control is valid.
+     */
+    public function setIsValid($value)
+    {
+        $this->_isValid=TPropertyValue::ensureBoolean($value);
+    }
+    public function getValidationPropertyValue()
+    {
+        return $this->Request[$this->getResponseFieldName()];
+    }
+    public function getResponseFieldName()
+    {
+        $captchas = $this->Page->findControlsByType('TReCaptcha2');
+        $cont = 0;
+        $responseFieldName = self::ChallengeFieldName;
+        foreach ($captchas as $captcha)
+        {
+            if ($this->getClientID() == $captcha->ClientID)
+            {
+                $responseFieldName .= ($cont > 0) ? '-'.$cont : '';
+            }
+            $cont++;
+        }
+        return $responseFieldName;
+    }
+    /**
+     * Returns your site key. 
+     * @return string.
+     */
+    public function getSiteKey()
+    {
+        return $this->getViewState('SiteKey');
+    }
+    /**
+     * @param string your site key.
+     */
+    public function setSiteKey($value)
+    {
+        $this->setViewState('SiteKey', TPropertyValue::ensureString($value));
+    }
+    /**
+     * Returns your secret key. 
+     * @return string.
+     */
+    public function getSecretKey()
+    {
+        return $this->getViewState('SecretKey');
+    }
+    /**
+     * @param string your secret key.
+     */
+    public function setSecretKey($value)
+    {
+        $this->setViewState('SecretKey', TPropertyValue::ensureString($value));
+    }
+    /**
+     * Returns your language.
+     * @return string.
+     */
+    public function getLanguage()
+    {
+        return $this->getViewState('Language', 'en');
+    }
+    /**
+     * @param string your language.
+     */
+    public function setLanguage($value)
+    {
+        $this->setViewState('Language', TPropertyValue::ensureString($value), 'en');
+    }
+    /**
+     * Returns the color theme of the widget. 
+     * @return string.
+     */
+    public function getTheme()
+    {
+        return $this->getViewState('Theme', 'light');
+    }
+    /**
+     * The color theme of the widget.
+     * Default: light
+     * @param string the color theme of the widget.
+     */
+    public function setTheme($value)
+    {
+        $this->setViewState('Theme', TPropertyValue::ensureString($value), 'light');
+    }
+    /**
+     * Returns the type of CAPTCHA to serve.
+     * @return string.
+     */
+    public function getType()
+    {
+        return $this->getViewState('Type', 'image');
+    }
+    /**
+     * The type of CAPTCHA to serve.
+     * Default: image
+     * @param string the type of CAPTCHA to serve.
+     */
+    public function setType($value)
+    {
+        $this->setViewState('Type', TPropertyValue::ensureString($value), 'image');
+    }
+    /**
+     * Returns the size of the widget.
+     * @return string.
+     */
+    public function getSize()
+    {
+        return $this->getViewState('Size', 'normal');
+    }
+    /**
+     * The size of the widget.
+     * Default: normal
+     * @param string the size of the widget.
+     */
+    public function setSize($value)
+    {
+        $this->setViewState('Size', TPropertyValue::ensureString($value), 'normal');
+    }
+    /**
+     * Returns the tabindex of the widget and challenge.
+     * If other elements in your page use tabindex, it should be set to make user navigation easier.
+     * @return string.
+     */
+    public function getTabIndex()
+    {
+        return $this->getViewState('TabIndex', 0);
+    }
+    /**
+     * The tabindex of the widget and challenge.
+     * If other elements in your page use tabindex, it should be set to make user navigation easier.
+     * Default: 0
+     * @param string the tabindex of the widget and challenge.
+     */
+    public function setTabIndex($value)
+    {
+        $this->setViewState('TabIndex', TPropertyValue::ensureInteger($value), 0);
+    }
+    /**
+     * Resets the reCAPTCHA widget.
+     * Optional widget ID, defaults to the first widget created if unspecified.
+     */
+    public function reset()
+    {
+        $this->Page->CallbackClient->callClientFunction('grecaptcha.reset',array(array($this->WidgetId)));
+    }
+    /**
+     * Gets the response for the reCAPTCHA widget.
+     */
+    public function getResponse()
+    {
+        return $this->getViewState('Response', '');
+    }
+    public function setResponse($value)
+    {
+        $this->setViewState('Response', TPropertyValue::ensureString($value), '');
+    }
+    public function getWidgetId()
+    {
+        return $this->getViewState('WidgetId', 0);
+    }
+    public function setWidgetId($value)
+    {
+        $this->setViewState('WidgetId', TPropertyValue::ensureInteger($value), 0);
+    }
+    protected function getClientOptions()
+    {
+        $options['ID'] = $this->getClientID();
+        $options['EventTarget'] = $this->getUniqueID();
+        $options['FormID'] = $this->Page->getForm()->getClientID();
+        $options['onCallback'] = $this->hasEventHandler('OnCallback');
+        $options['onCallbackExpired'] = $this->hasEventHandler('OnCallbackExpired');
+        $options['options']['sitekey'] = $this->getSiteKey();
+        if ($theme = $this->getTheme()) $options['options']['theme'] = $theme;
+        if ($type = $this->getType()) $options['options']['type'] = $type;
+        if ($size = $this->getSize()) $options['options']['size'] = $size;
+        if ($tabIndex = $this->getTabIndex()) $options['options']['tabindex'] = $tabIndex;
+
+        return $options;
+    }
+    protected function registerClientScript()
+    {
+        $id         = $this->getClientID();
+        $options    = TJavaScript::encode($this->getClientOptions());
+        $className  = $this->getClientClassName();
+        $cs         = $this->Page->ClientScript;
+        $code       = "new $className($options);";
+
+        $cs->registerPradoScript('ajax');
+        $cs->registerEndScript("grecaptcha:$id", $code);
+    }
+    public function validate()
+    {
+        if ((is_null($this->getValidationPropertyValue())) || (empty($this->getValidationPropertyValue())))
+            return false;
+
+        return true;
+    }
+    /**
+     * Checks for API keys
+     * @param mixed event parameter
+     */
+    public function onPreRender($param)
+    {
+        parent::onPreRender($param);
+
+        if("" == $this->getSiteKey())
+            throw new TConfigurationException('recaptcha_publickey_unknown');
+        if("" == $this->getSecretKey())
+            throw new TConfigurationException('recaptcha_privatekey_unknown');
+
+        // need to register captcha fields so they will be sent postback
+        $this->Page->registerRequiresPostData($this->getResponseFieldName());
+        $this->Page->ClientScript->registerHeadScriptFile('grecaptcha2', 'https://www.google.com/recaptcha/api.js?onload=TReCaptcha2_onloadCallback&render=explicit&hl=' . $this->getLanguage());
+    }
+    protected function addAttributesToRender($writer)
+    {
+        $writer->addAttribute('id',$this->getClientID());
+        parent::addAttributesToRender($writer);
+    }
+    public function raiseCallbackEvent($param)
+    {
+        $params = $param->getCallbackParameter();
+        if ($params instanceof stdClass)
+        {
+            $callback = property_exists($params, 'onCallback');
+            $callbackExpired = property_exists($params, 'onCallbackExpired');
+
+            if ($callback)
+            {
+                $this->WidgetId = $params->widgetId;
+                $this->Response = $params->response;
+                $this->Page->CallbackClient->jQuery($params->responseField, 'text',array($params->response));
+
+                if ($params->onCallback)
+                {
+                    $this->onCallback($param);
+                }
+            }
+
+            if ($callbackExpired)
+            {
+                $this->Response = '';
+                $this->reset();
+
+                if ($params->onCallbackExpired)
+                {
+                    $this->onCallbackExpired($param);
+                }
+            }
+        }
+    }
+
+    public function onCallback($param)
+    {
+        $this->raiseEvent('OnCallback', $this, $param);
+    }
+
+    public function onCallbackExpired($param)
+    {
+        $this->raiseEvent('OnCallbackExpired', $this, $param);
+    }
+
+    public function render($writer)
+    {
+        $this->registerClientScript();
+        parent::render($writer);
+    }
+}
diff --git a/framework/Web/UI/WebControls/TReCaptcha2Validator.php b/framework/Web/UI/WebControls/TReCaptcha2Validator.php
new file mode 100644
index 00000000..2cd4b6d1
--- /dev/null
+++ b/framework/Web/UI/WebControls/TReCaptcha2Validator.php
@@ -0,0 +1,110 @@
+<?php
+
+/**
+ * TReCaptcha2Validator class file
+ *
+ * @author Cristian Camilo Naranjo Valencia
+ * @link http://icolectiva.co
+ * @copyright Copyright &copy; 2005-2016 The PRADO Group
+ * @license https://github.com/pradosoft/prado/blob/master/COPYRIGHT
+ * @package System.Web.UI.WebControls
+ */
+
+Prado::using('System.Web.UI.WebControls.TBaseValidator');
+Prado::using('System.Web.UI.WebControls.TReCaptcha2');
+
+/**
+ * TReCaptcha2Validator class
+ *
+ * TReCaptcha2Validator validates a reCAPTCHA represented by a {@link TReCaptcha} control.
+ * The input control fails validation if th user did not pass the humanity test.
+ *
+ * To use TReCaptcha2Validator, specify the {@link setCaptchaControl CaptchaControl}
+ * to be the ID path of the {@link TReCaptcha} control.
+ *
+ * @author Cristian Camilo Naranjo Valencia
+ * @package System.Web.UI.WebControls
+ * @since 3.3.1
+ */
+
+class TReCaptcha2Validator extends TBaseValidator
+{
+    protected $_isvalid = null;
+
+    protected function getClientClassName()
+    {
+        return 'Prado.WebUI.TReCaptcha2Validator';
+    }
+    public function getEnableClientScript()
+    {
+        return true;
+    }
+    protected function getCaptchaControl()
+    {
+        $control = $this->getValidationTarget();
+        if (!$control)
+            throw new Exception('No target control specified for TReCaptcha2Validator');
+        if (!($control instanceof TReCaptcha2))
+            throw new Exception('TReCaptcha2Validator only works with TReCaptcha2 controls');
+        return $control;
+    }
+    public function getClientScriptOptions()
+    {
+        $options = parent::getClientScriptOptions();
+        $options['ResponseFieldName'] = $this->getCaptchaControl()->getResponseFieldName();
+        return $options;
+    }
+    /**
+     * This method overrides the parent's implementation.
+     * The validation succeeds if the input control has the same value
+     * as the one displayed in the corresponding RECAPTCHA control.
+     *
+     * @return boolean whether the validation succeeds
+     */
+    protected function evaluateIsValid()
+    {
+        // check validity only once (if trying to evaulate multiple times, all redundant checks would fail)
+        if (is_null($this->_isvalid))
+        {
+            $control = $this->getCaptchaControl();
+            $this->_isvalid = $control->validate();
+        }
+        return ($this->_isvalid==true);
+    }
+    public function onPreRender($param)
+    {
+        parent::onPreRender($param);
+
+        $cs = $this->Page->getClientScript();
+        $cs->registerPradoScript('validator');
+
+        // communicate validation status to the client side
+        $value = $this->_isvalid===false ? '0' : '1';
+        $cs->registerHiddenField($this->getClientID().'_1',$value);
+
+        // update validator display
+        if ($control = $this->getValidationTarget())
+        {
+            $fn = 'captchaUpdateValidatorStatus_'.$this->getClientID();
+
+            $cs->registerEndScript($this->getClientID().'::validate', implode(' ',array(
+                // this function will be used to update the validator
+                'function '.$fn.'(valid)',
+                '{',
+                '  jQuery('.TJavaScript::quoteString('#'.$this->getClientID().'_1').').val(valid);',
+                '  Prado.Validation.validateControl('.TJavaScript::quoteString($control->ClientID).'); ',
+                '}',
+                '',
+                // update the validator to the result if we're in a callback 
+                // (if we're in initial rendering or a postback then the result will be rendered directly to the page html anyway)
+                $this->Page->IsCallback ? $fn.'('.$value.');' : '',
+                '',
+                // install event handler that clears the validation error when user changes the captcha response field
+                'jQuery("#'.$control->getClientID().'").on("change", '.TJavaScript::quoteString('#'.$control->getResponseFieldName()).', function() { ',
+                    $fn.'("1");',
+                '});',
+            )));
+        }
+    }
+}
+
diff --git a/framework/Web/UI/WebControls/TReCaptchaValidator.php b/framework/Web/UI/WebControls/TReCaptchaValidator.php
index de3b42a5..9078354b 100644
--- a/framework/Web/UI/WebControls/TReCaptchaValidator.php
+++ b/framework/Web/UI/WebControls/TReCaptchaValidator.php
@@ -21,7 +21,7 @@ Prado::using('System.Web.UI.WebControls.TReCaptcha');
  * is not the same as the token displayed in reCAPTCHA. Note, if the user does
  * not enter any thing, it is still considered as failing the validation.
  *
- * To use TReCaptchaValidator, specify the {@link setControlToValidate ControlToValidate}
+ * To use TReCaptchaValidator, specify the {@link setCaptchaControl CaptchaControl}
  * to be the ID path of the {@link TReCaptcha} control.
  *
  * @author Bérczi Gábor <gabor.berczi@devworx.hu>