File size: 6.02Kb
<?php
/**
* CCaptcha class file.
*
* @author Qiang Xue <[email protected]>
* @link http://www.yiiframework.com/
* @copyright Copyright © 2008-2011 Yii Software LLC
* @license http://www.yiiframework.com/license/
*/
/**
* CCaptcha renders a CAPTCHA image element.
*
* CCaptcha is used together with {@link CCaptchaAction} to provide {@link http://en.wikipedia.org/wiki/Captcha CAPTCHA}
* - a way of preventing site spam.
*
* The image element rendered by CCaptcha will display a CAPTCHA image generated
* by an action of class {@link CCaptchaAction} belonging to the current controller.
* By default, the action ID should be 'captcha', which can be changed by setting {@link 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 {@link clickableImage} is set true, clicking on the CAPTCHA image
* will refresh the CAPTCHA.
*
* A {@link CCaptchaValidator} may be used to validate that the user enters
* a verification code matching the code displayed in the CAPTCHA image.
*
* @author Qiang Xue <[email protected]>
* @package system.web.widgets.captcha
* @since 1.0
*/
class CCaptcha extends CWidget
{
/**
* @var string 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 {@link CController::createUrl} to create the URL that would serve the CAPTCHA image.
* The action has to be of {@link CCaptchaAction}.
*/
public $captchaAction='captcha';
/**
* @var boolean 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.
*/
public $showRefreshButton=true;
/**
* @var boolean whether to allow clicking on the CAPTCHA image to refresh the CAPTCHA letters.
* Defaults to false. Hint: you may want to set {@link showRefreshButton} to false if you set
* this property to be true because they serve for the same purpose.
* To enhance accessibility, you may set {@link imageOptions} to provide hints to end-users that
* the image is clickable.
*/
public $clickableImage=false;
/**
* @var string the label for the refresh button. Defaults to 'Get a new code'.
*/
public $buttonLabel;
/**
* @var string 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'.
*/
public $buttonType='link';
/**
* @var array HTML attributes to be applied to the rendered image element.
*/
public $imageOptions=array();
/**
* @var array HTML attributes to be applied to the rendered refresh button element.
*/
public $buttonOptions=array();
/**
* Renders the widget.
*/
public function run()
{
if(self::checkRequirements('imagick') || self::checkRequirements('gd'))
{
$this->renderImage();
$this->registerClientScript();
}
else
throw new CException(Yii::t('yii','GD with FreeType or ImageMagick PHP extensions are required.'));
}
/**
* Renders the CAPTCHA image.
*/
protected function renderImage()
{
if(!isset($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);
}
/**
* Registers the needed client scripts.
*/
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,$js);
}
/**
* Checks if specified graphic extension support is loaded.
* @param string extension name to be checked. Possible values are 'gd', 'imagick' and null.
* Default value is null meaning that both extensions will be checked. This parameter
* is available since 1.1.13.
* @return boolean true if ImageMagick extension with PNG support or GD with FreeType support is loaded,
* otherwise false
* @since 1.1.5
*/
public static function checkRequirements($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;
}
}