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CCaptcha

Package	system.web.widgets.captcha
Inheritance	class CCaptcha » CWidget » CBaseController » CComponent
Since	1.0
Source Code	framework/web/widgets/captcha/CCaptcha.php

CCaptcha renders a CAPTCHA image element.

CCaptcha is used together with CCaptchaAction to provide CAPTCHA - a way of preventing site spam.

The image element rendered by CCaptcha will display a CAPTCHA image generated by an action of class CCaptchaAction belonging to the current controller. By default, the action ID should be 'captcha', which can be changed by setting captchaAction.

CCaptcha may also render a button next to the CAPTCHA image. Clicking on the button will change the CAPTCHA image to be a new one in an AJAX way.

If clickableImage is set true, clicking on the CAPTCHA image will refresh the CAPTCHA.

A CCaptchaValidator may be used to validate that the user enters a verification code matching the code displayed in the CAPTCHA image.

When combining CCaptcha with CActiveForm or CForm, make sure ajaxValidation is disabled. Performing ajax validation causes your Captcha to be refreshed, rendering the code invalid on the next validation attempt.

Public Properties

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Property	Type	Description	Defined By
actionPrefix	string	the prefix to the IDs of the actions.	CWidget
buttonLabel	string	the label for the refresh button.	CCaptcha
buttonOptions	array	HTML attributes to be applied to the rendered refresh button element.	CCaptcha
buttonType	string	the type of the refresh button.	CCaptcha
captchaAction	string	the ID of the action that should provide CAPTCHA image.	CCaptcha
clickableImage	boolean	whether to allow clicking on the CAPTCHA image to refresh the CAPTCHA letters.	CCaptcha
controller	CController	Returns the controller that this widget belongs to.	CWidget
id	string	Returns the ID of the widget or generates a new one if requested.	CWidget
imageOptions	array	HTML attributes to be applied to the rendered image element.	CCaptcha
owner	CBaseController	Returns the owner/creator of this widget.	CWidget
showRefreshButton	boolean	whether to display a button next to the CAPTCHA image.	CCaptcha
skin	mixed	the name of the skin to be used by this widget.	CWidget
viewPath	string	Returns the directory containing the view files for this widget.	CWidget

Public Methods

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Method	Description	Defined By
__call()	Calls the named method which is not a class method.	CComponent
__construct()	Constructor.	CWidget
__get()	Returns a property value, an event handler list or a behavior based on its name.	CComponent
__isset()	Checks if a property value is null.	CComponent
__set()	Sets value of a component property.	CComponent
__unset()	Sets a component property to be null.	CComponent
actions()	Returns a list of actions that are used by this widget.	CWidget
asa()	Returns the named behavior object.	CComponent
attachBehavior()	Attaches a behavior to this component.	CComponent
attachBehaviors()	Attaches a list of behaviors to the component.	CComponent
attachEventHandler()	Attaches an event handler to an event.	CComponent
beginCache()	Begins fragment caching.	CBaseController
beginClip()	Begins recording a clip.	CBaseController
beginContent()	Begins the rendering of content that is to be decorated by the specified view.	CBaseController
beginWidget()	Creates a widget and executes it.	CBaseController
canGetProperty()	Determines whether a property can be read.	CComponent
canSetProperty()	Determines whether a property can be set.	CComponent
checkRequirements()	Checks if specified graphic extension support is loaded.	CCaptcha
createWidget()	Creates a widget and initializes it.	CBaseController
detachBehavior()	Detaches a behavior from the component.	CComponent
detachBehaviors()	Detaches all behaviors from the component.	CComponent
detachEventHandler()	Detaches an existing event handler.	CComponent
disableBehavior()	Disables an attached behavior.	CComponent
disableBehaviors()	Disables all behaviors attached to this component.	CComponent
enableBehavior()	Enables an attached behavior.	CComponent
enableBehaviors()	Enables all behaviors attached to this component.	CComponent
endCache()	Ends fragment caching.	CBaseController
endClip()	Ends recording a clip.	CBaseController
endContent()	Ends the rendering of content.	CBaseController
endWidget()	Ends the execution of the named widget.	CBaseController
evaluateExpression()	Evaluates a PHP expression or callback under the context of this component.	CComponent
getController()	Returns the controller that this widget belongs to.	CWidget
getEventHandlers()	Returns the list of attached event handlers for an event.	CComponent
getId()	Returns the ID of the widget or generates a new one if requested.	CWidget
getOwner()	Returns the owner/creator of this widget.	CWidget
getViewFile()	Looks for the view script file according to the view name.	CWidget
getViewPath()	Returns the directory containing the view files for this widget.	CWidget
hasEvent()	Determines whether an event is defined.	CComponent
hasEventHandler()	Checks whether the named event has attached handlers.	CComponent
hasProperty()	Determines whether a property is defined.	CComponent
init()	Initializes the widget.	CWidget
raiseEvent()	Raises an event.	CComponent
registerClientScript()	Registers the needed client scripts.	CCaptcha
render()	Renders a view.	CWidget
renderFile()	Renders a view file.	CBaseController
renderInternal()	Renders a view file.	CBaseController
run()	Renders the widget.	CCaptcha
setId()	Sets the ID of the widget.	CWidget
widget()	Creates a widget and executes it.	CBaseController

Protected Methods

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Method	Description	Defined By
renderImage()	Renders the CAPTCHA image.	CCaptcha

Property Details

buttonLabel property

public string $buttonLabel;

the label for the refresh button. Defaults to 'Get a new code'.

buttonOptions property

public array $buttonOptions;

HTML attributes to be applied to the rendered refresh button element.

buttonType property

public string $buttonType;

the type of the refresh button. This should be either 'link' or 'button'. The former refers to hyperlink button while the latter a normal push button. Defaults to 'link'.

captchaAction property

public string $captchaAction;

the ID of the action that should provide CAPTCHA image. Defaults to 'captcha', meaning the 'captcha' action of the current controller. This property may also be in the format of 'ControllerID/ActionID'. Underneath, this property is used by CController::createUrl to create the URL that would serve the CAPTCHA image. The action has to be of CCaptchaAction.

clickableImage property

public boolean $clickableImage;

whether to allow clicking on the CAPTCHA image to refresh the CAPTCHA letters. Defaults to false. Hint: you may want to set showRefreshButton to false if you set this property to be true because they serve for the same purpose. To enhance accessibility, you may set imageOptions to provide hints to end-users that the image is clickable.

imageOptions property

public array $imageOptions;

HTML attributes to be applied to the rendered image element.

showRefreshButton property

public boolean $showRefreshButton;

whether to display a button next to the CAPTCHA image. Clicking on the button will cause the CAPTCHA image to be changed to a new one. Defaults to true.

Method Details

checkRequirements() method (available since v1.1.5)

public static boolean checkRequirements(string $extension=NULL)
$extension	string	name to be checked. Possible values are 'gd', 'imagick' and null. Default value is null meaning that both extensions will be checked. This parameter is available since 1.1.13.
{return}	boolean	true if ImageMagick extension with PNG support or GD with FreeType support is loaded, otherwise false

Source Code: framework/web/widgets/captcha/CCaptcha.php#167 (show)


public static function checkRequirements($extension=null)
{
    if(extension_loaded('imagick'))
    {
        $imagick=new Imagick();
        $imagickFormats=$imagick->queryFormats('PNG');
    }
    if(extension_loaded('gd'))
    {
        $gdInfo=gd_info();
    }
    if($extension===null)
    {
        if(isset($imagickFormats) && in_array('PNG',$imagickFormats))
            return true;
        if(isset($gdInfo) && $gdInfo['FreeType Support'])
            return true;
    }
    elseif($extension=='imagick' && isset($imagickFormats) && in_array('PNG',$imagickFormats))
        return true;
    elseif($extension=='gd' && isset($gdInfo) && $gdInfo['FreeType Support'])
        return true;
    return false;
}

Checks if specified graphic extension support is loaded.

registerClientScript() method

public void registerClientScript()

Source Code: framework/web/widgets/captcha/CCaptcha.php#110 (show)


public function registerClientScript()
{
    $cs=Yii::app()->clientScript;
    $id=$this->imageOptions['id'];
    $url=$this->getController()->createUrl($this->captchaAction,array(CCaptchaAction::REFRESH_GET_VAR=>true));

    $js="";
    if($this->showRefreshButton)
    {
        // reserve a place in the registered script so that any enclosing button js code appears after the captcha js
        $cs->registerScript('Yii.CCaptcha#'.$id,'// dummy');
        $label=$this->buttonLabel===null?Yii::t('yii','Get a new code'):$this->buttonLabel;
        $options=$this->buttonOptions;
        if(isset($options['id']))
            $buttonID=$options['id'];
        else
            $buttonID=$options['id']=$id.'_button';
        if($this->buttonType==='button')
            $html=CHtml::button($label, $options);
        else
            $html=CHtml::link($label, $url, $options);
        $js="jQuery('#$id').after(".CJSON::encode($html).");";
        $selector="#$buttonID";
    }

    if($this->clickableImage)
        $selector=isset($selector) ? "$selector, #$id" : "#$id";

    if(!isset($selector))
        return;

    $js.="
jQuery(document).on('click', '$selector', function(){
jQuery.ajax({
    url: ".CJSON::encode($url).",
    dataType: 'json',
    cache: false,
    success: function(data) {
        jQuery('#$id').attr('src', data['url']);
        jQuery('body').data('{$this->captchaAction}.hash', [data['hash1'], data['hash2']]);
    }
});
return false;
});
";
    $cs->registerScript('Yii.CCaptcha#'.$id,$js);
}

Registers the needed client scripts.

renderImage() method

protected void renderImage()

Source Code: framework/web/widgets/captcha/CCaptcha.php#97 (show)


protected function renderImage()
{
    if(!isset($this->imageOptions['id']))
        $this->imageOptions['id']=$this->getId();

    $url=$this->getController()->createUrl($this->captchaAction,array('v'=>uniqid()));
    $alt=isset($this->imageOptions['alt'])?$this->imageOptions['alt']:'';
    echo CHtml::image($url,$alt,$this->imageOptions);
}

Renders the CAPTCHA image.

run() method

public void run()

Source Code: framework/web/widgets/captcha/CCaptcha.php#83 (show)


public function run()
{
    if(self::checkRequirements('imagick') || self::checkRequirements('gd'))
    {
        $this->renderImage();
        $this->registerClientScript();
    }
    else
        throw new CException(Yii::t('yii','GD with FreeType or ImageMagick PHP extensions are required.'));
}

Renders the widget.