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CCaptchaAction

Package system.web.widgets.captcha
Inheritance class CCaptchaAction » CAction » CComponent
Implements IAction
Since 1.0
Source Code framework/web/widgets/captcha/CCaptchaAction.php
CCaptchaAction renders a CAPTCHA image.

CCaptchaAction is used together with CCaptcha and CCaptchaValidator to provide the CAPTCHA feature.

You must configure properties of CCaptchaAction to customize the appearance of the generated image.

Note, CCaptchaAction requires PHP GD2 extension.

Using CAPTCHA involves the following steps:
  1. Override CController::actions() and register an action of class CCaptchaAction with ID 'captcha'.
  2. In the form model, declare an attribute to store user-entered verification code, and declare the attribute to be validated by the 'captcha' validator.
  3. In the controller view, insert a CCaptcha widget in the form.

Public Properties

Hide inherited properties

PropertyTypeDescriptionDefined By
backColor integer the background color. CCaptchaAction
backend string the graphic extension that will be used to draw CAPTCHA image. CCaptchaAction
controller CController the controller who owns this action. CAction
fixedVerifyCode string the fixed verification code. CCaptchaAction
fontFile string the TrueType font file. CCaptchaAction
foreColor integer the font color. CCaptchaAction
height integer the height of the generated CAPTCHA image. CCaptchaAction
id string id of this action CAction
maxLength integer the maximum length for randomly generated word. CCaptchaAction
minLength integer the minimum length for randomly generated word. CCaptchaAction
offset integer the offset between characters. CCaptchaAction
padding integer padding around the text. CCaptchaAction
testLimit integer how many times should the same CAPTCHA be displayed. CCaptchaAction
transparent boolean whether to use transparent background. CCaptchaAction
verifyCode string Gets the verification code. CCaptchaAction
width integer the width of the generated CAPTCHA image. CCaptchaAction

Protected Properties

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PropertyTypeDescriptionDefined By
sessionKey string Returns the session variable name used to store verification code. CCaptchaAction

Public Methods

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MethodDescriptionDefined By
__call() Calls the named method which is not a class method. CComponent
__construct() Constructor. CAction
__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
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
canGetProperty() Determines whether a property can be read. CComponent
canSetProperty() Determines whether a property can be set. CComponent
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
evaluateExpression() Evaluates a PHP expression or callback under the context of this component. CComponent
generateValidationHash() Generates a hash code that can be used for client side validation. CCaptchaAction
getController() Returns the controller who owns this action. CAction
getEventHandlers() Returns the list of attached event handlers for an event. CComponent
getId() Returns id of this action CAction
getVerifyCode() Gets the verification code. CCaptchaAction
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
raiseEvent() Raises an event. CComponent
run() Runs the action. CCaptchaAction
runWithParams() Runs the action with the supplied request parameters. CAction
validate() Validates the input to see if it matches the generated code. CCaptchaAction

Protected Methods

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MethodDescriptionDefined By
generateVerifyCode() Generates a new verification code. CCaptchaAction
getSessionKey() Returns the session variable name used to store verification code. CCaptchaAction
renderImage() Renders the CAPTCHA image based on the code using library specified in the $backend property. CCaptchaAction
renderImageGD() Renders the CAPTCHA image based on the code using GD library. CCaptchaAction
renderImageImagick() Renders the CAPTCHA image based on the code using ImageMagick library. CCaptchaAction
runWithParamsInternal() Executes a method of an object with the supplied named parameters. CAction

Property Details

backColor property
public integer $backColor;

the background color. For example, 0x55FF00. Defaults to 0xFFFFFF, meaning white color.

backend property (available since v1.1.13)
public string $backend;

the graphic extension that will be used to draw CAPTCHA image. Possible values are 'gd', 'imagick' and null. Null value means that fallback mode will be used: ImageMagick is preferred over GD. Default value is null.

fixedVerifyCode property (available since v1.1.4)
public string $fixedVerifyCode;

the fixed verification code. When this is property is set, getVerifyCode will always return this value. This is mainly used in automated tests where we want to be able to reproduce the same verification code each time we run the tests. Defaults to null, meaning the verification code will be randomly generated.

fontFile property
public string $fontFile;

the TrueType font file. Defaults to SpicyRice.ttf which is provided with the Yii release. Note that non-free Duality.ttf has been changed to open/free SpicyRice.ttf since 1.1.14.

foreColor property
public integer $foreColor;

the font color. For example, 0x55FF00. Defaults to 0x2040A0 (blue color).

height property
public integer $height;

the height of the generated CAPTCHA image. Defaults to 50.

maxLength property
public integer $maxLength;

the maximum length for randomly generated word. Defaults to 7.

minLength property
public integer $minLength;

the minimum length for randomly generated word. Defaults to 6.

offset property (available since v1.1.7)
public integer $offset;

the offset between characters. Defaults to -2. You can adjust this property in order to decrease or increase the readability of the captcha.

padding property
public integer $padding;

padding around the text. Defaults to 2.

sessionKey property read-only
protected string getSessionKey()

Returns the session variable name used to store verification code.

testLimit property
public integer $testLimit;

how many times should the same CAPTCHA be displayed. Defaults to 3. A value less than or equal to 0 means the test is unlimited (available since version 1.1.2).

transparent property
public boolean $transparent;

whether to use transparent background. Defaults to false.

verifyCode property read-only
public string getVerifyCode(boolean $regenerate=false)

Gets the verification code.

width property
public integer $width;

the width of the generated CAPTCHA image. Defaults to 120.

Method Details

generateValidationHash() method (available since v1.1.7)
public string generateValidationHash(string $code)
$code string the CAPTCHA code
{return} string a hash code generated from the CAPTCHA code
Source Code: framework/web/widgets/captcha/CCaptchaAction.php#140 (show)
public function generateValidationHash($code)
{
    for(
$h=0,$i=strlen($code)-1;$i>=0;--$i)
        
$h+=ord($code[$i]);
    return 
$h;
}

Generates a hash code that can be used for client side validation.

generateVerifyCode() method
protected string generateVerifyCode()
{return} string the generated verification code
Source Code: framework/web/widgets/captcha/CCaptchaAction.php#191 (show)
protected function generateVerifyCode()
{
    if(
$this->minLength $this->maxLength)
        
$this->maxLength $this->minLength;
    if(
$this->minLength 3)
        
$this->minLength 3;
    if(
$this->maxLength 20)
        
$this->maxLength 20;
    
$length mt_rand($this->minLength,$this->maxLength);

    
$letters 'bcdfghjklmnpqrstvwxyz';
    
$vowels 'aeiou';
    
$code '';
    for(
$i 0$i $length; ++$i)
    {
        if(
$i && mt_rand(0,10) > || !($i 2) && mt_rand(0,10) > 9)
            
$code.=$vowels[mt_rand(0,4)];
        else
            
$code.=$letters[mt_rand(0,20)];
    }

    return 
$code;
}

Generates a new verification code.

getSessionKey() method
protected string getSessionKey()
{return} string the session variable name
Source Code: framework/web/widgets/captcha/CCaptchaAction.php#219 (show)
protected function getSessionKey()
{
    return 
self::SESSION_VAR_PREFIX Yii::app()->getId() . '.' $this->getController()->getUniqueId() . '.' $this->getId();
}

Returns the session variable name used to store verification code.

getVerifyCode() method
public string getVerifyCode(boolean $regenerate=false)
$regenerate boolean whether the verification code should be regenerated.
{return} string the verification code.
Source Code: framework/web/widgets/captcha/CCaptchaAction.php#152 (show)
public function getVerifyCode($regenerate=false)
{
    if(
$this->fixedVerifyCode !== null)
        return 
$this->fixedVerifyCode;

    
$session Yii::app()->session;
    
$session->open();
    
$name $this->getSessionKey();
    if(
$session[$name] === null || $regenerate)
    {
        
$session[$name] = $this->generateVerifyCode();
        
$session[$name 'count'] = 1;
    }
    return 
$session[$name];
}

Gets the verification code.

renderImage() method
protected void renderImage(string $code)
$code string the verification code
Source Code: framework/web/widgets/captcha/CCaptchaAction.php#228 (show)
protected function renderImage($code)
{
    if(
$this->backend===null && CCaptcha::checkRequirements('imagick') || $this->backend==='imagick')
        
$this->renderImageImagick($code);
    else if(
$this->backend===null && CCaptcha::checkRequirements('gd') || $this->backend==='gd')
        
$this->renderImageGD($code);
}

Renders the CAPTCHA image based on the code using library specified in the $backend property.

renderImageGD() method (available since v1.1.13)
protected void renderImageGD(string $code)
$code string the verification code
Source Code: framework/web/widgets/captcha/CCaptchaAction.php#241 (show)
protected function renderImageGD($code)
{
    
$image imagecreatetruecolor($this->width,$this->height);

    
$backColor imagecolorallocate($image,
            (int)(
$this->backColor 0x1000000 0x10000),
            (int)(
$this->backColor 0x10000 0x100),
            
$this->backColor 0x100);
    
imagefilledrectangle($image,0,0,$this->width,$this->height,$backColor);
    
imagecolordeallocate($image,$backColor);

    if(
$this->transparent)
        
imagecolortransparent($image,$backColor);

    
$foreColor imagecolorallocate($image,
            (int)(
$this->foreColor 0x1000000 0x10000),
            (int)(
$this->foreColor 0x10000 0x100),
            
$this->foreColor 0x100);

    if(
$this->fontFile === null)
        
$this->fontFile dirname(__FILE__) . '/SpicyRice.ttf';

    
$length strlen($code);
    
$box imagettfbbox(30,0,$this->fontFile,$code);
    
$w $box[4] - $box[0] + $this->offset * ($length 1);
    
$h $box[1] - $box[5];
    
$scale min(($this->width $this->padding 2) / $w,($this->height $this->padding 2) / $h);
    
$x 10;
    
$y round($this->height 27 40);
    for(
$i 0$i $length; ++$i)
    {
        
$fontSize = (int)(rand(26,32) * $scale 0.8);
        
$angle rand(-10,10);
        
$letter $code[$i];
        
$box imagettftext($image,$fontSize,$angle,$x,$y,$foreColor,$this->fontFile,$letter);
        
$x $box[2] + $this->offset;
    }

    
imagecolordeallocate($image,$foreColor);

    
header('Pragma: public');
    
header('Expires: 0');
    
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
    
header('Content-Transfer-Encoding: binary');
    
header("Content-Type: image/png");
    
imagepng($image);
    
imagedestroy($image);
}

Renders the CAPTCHA image based on the code using GD library.

renderImageImagick() method (available since v1.1.13)
protected void renderImageImagick(string $code)
$code string the verification code
Source Code: framework/web/widgets/captcha/CCaptchaAction.php#295 (show)
protected function renderImageImagick($code)
{
    
$backColor=$this->transparent ? new ImagickPixel('transparent') : new ImagickPixel(sprintf('#%06x',$this->backColor));
    
$foreColor=new ImagickPixel(sprintf('#%06x',$this->foreColor));

    
$image=new Imagick();
    
$image->newImage($this->width,$this->height,$backColor);

    if(
$this->fontFile===null)
        
$this->fontFile=dirname(__FILE__).'/SpicyRice.ttf';

    
$draw=new ImagickDraw();
    
$draw->setFont($this->fontFile);
    
$draw->setFontSize(30);
    
$fontMetrics=$image->queryFontMetrics($draw,$code);

    
$length=strlen($code);
    
$w=(int)($fontMetrics['textWidth'])-8+$this->offset*($length-1);
    
$h=(int)($fontMetrics['textHeight'])-8;
    
$scale=min(($this->width-$this->padding*2)/$w,($this->height-$this->padding*2)/$h);
    
$x=10;
    
$y=round($this->height*27/40);
    for(
$i=0$i<$length; ++$i)
    {
        
$draw=new ImagickDraw();
        
$draw->setFont($this->fontFile);
        
$draw->setFontSize((int)(rand(26,32)*$scale*0.8));
        
$draw->setFillColor($foreColor);
        
$image->annotateImage($draw,$x,$y,rand(-10,10),$code[$i]);
        
$fontMetrics=$image->queryFontMetrics($draw,$code[$i]);
        
$x+=(int)($fontMetrics['textWidth'])+$this->offset;
    }

    
header('Pragma: public');
    
header('Expires: 0');
    
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
    
header('Content-Transfer-Encoding: binary');
    
header("Content-Type: image/png");
    
$image->setImageFormat('png');
    echo 
$image;
}

Renders the CAPTCHA image based on the code using ImageMagick library.

run() method
public void run()
Source Code: framework/web/widgets/captcha/CCaptchaAction.php#116 (show)
public function run()
{
    if(isset(
$_GET[self::REFRESH_GET_VAR]))  // AJAX request for regenerating code
    
{
        
$code=$this->getVerifyCode(true);
        echo 
CJSON::encode(array(
            
'hash1'=>$this->generateValidationHash($code),
            
'hash2'=>$this->generateValidationHash(strtolower($code)),
            
// we add a random 'v' parameter so that FireFox can refresh the image
            // when src attribute of image tag is changed
            
'url'=>$this->getController()->createUrl($this->getId(),array('v' => uniqid())),
        ));
    }
    else
        
$this->renderImage($this->getVerifyCode());
    
Yii::app()->end();
}

Runs the action.

validate() method
public boolean validate(string $input, boolean $caseSensitive)
$input string user input
$caseSensitive boolean whether the comparison should be case-sensitive
{return} boolean whether the input is valid
Source Code: framework/web/widgets/captcha/CCaptchaAction.php#174 (show)
public function validate($input,$caseSensitive)
{
    
$code $this->getVerifyCode();
    
$valid $caseSensitive ? ($input === $code) : strcasecmp($input,$code)===0;
    
$session Yii::app()->session;
    
$session->open();
    
$name $this->getSessionKey() . 'count';
    
$session[$name] = $session[$name] + 1;
    if(
$session[$name] > $this->testLimit && $this->testLimit 0)
        
$this->getVerifyCode(true);
    return 
$valid;
}

Validates the input to see if it matches the generated code.

Total 1 comment

#4832 report it
dckurushin at 2011/08/20 02:04am
Manually create CCaptchaAction

If you want to create CCaptchaAction use this:

$captcha = Yii::app()->getController()->createAction('captcha');
$captcha->validate("answer...", false);

*this is if you want to validate it manually!!!

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