# Class yii\captcha\CaptchaAction

Inheritance | yii\captcha\CaptchaAction » yii\base\Action » yii\base\Component » yii\base\BaseObject
Implements | yii\base\Configurable
Available since version | 2.0
Source Code | https://github.com/yiisoft/yii2/blob/master/framework/captcha/CaptchaAction.php

CaptchaAction renders a CAPTCHA image.

CaptchaAction is used together with yii\captcha\Captcha and yii\captcha\CaptchaValidator to provide the CAPTCHA feature.

By configuring the properties of CaptchaAction, you may customize the appearance of the generated CAPTCHA images, such as the font color, the background color, etc.

Note that CaptchaAction requires either GD2 extension or ImageMagick PHP extension.

Using CAPTCHA involves the following steps:

1. Override yii\web\Controller::actions() and register an action of class CaptchaAction 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 yii\captcha\Captcha widget in the form.

## Public Properties

Hide inherited properties

Property | Type | Description | Defined By
--- | --- | --- | ---
$backColor | integer | The background color. | yii\captcha\CaptchaAction
$behaviors | yii\base\Behavior[] | List of behaviors attached to this component. This property is read-only. | yii\base\Component
$controller | yii\base\Controller|yii\web\Controller|yii\console\Controller | The controller that owns this action | yii\base\Action
$fixedVerifyCode | string | The fixed verification code. | yii\captcha\CaptchaAction
$fontFile | string | The TrueType font file. | yii\captcha\CaptchaAction
$foreColor | integer | The font color. | yii\captcha\CaptchaAction
$height | integer | The height of the generated CAPTCHA image. | yii\captcha\CaptchaAction
$id | string | ID of the action | yii\base\Action
$imageLibrary | string | The rendering library to use. | yii\captcha\CaptchaAction
$maxLength | integer | The maximum length for randomly generated word. | yii\captcha\CaptchaAction
$minLength | integer | The minimum length for randomly generated word. | yii\captcha\CaptchaAction
$offset | integer | The offset between characters. | yii\captcha\CaptchaAction
$padding | integer | Padding around the text. | yii\captcha\CaptchaAction
$testLimit | integer | How many times should the same CAPTCHA be displayed. | yii\captcha\CaptchaAction
$transparent | boolean | Whether to use transparent background. | yii\captcha\CaptchaAction
$uniqueId | string | The unique ID of this action among the whole application. This property is read-only. | yii\base\Action
$verifyCode | string | The verification code. This property is read-only. | yii\captcha\CaptchaAction
$width | integer | The width of the generated CAPTCHA image. | yii\captcha\CaptchaAction

## Public Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
__call() | Calls the named method which is not a class method. | yii\base\Component
__clone() | This method is called after the object is created by cloning an existing one. | yii\base\Component
__construct() | Constructor. | yii\base\Action
__get() | Returns the value of a component property. | yii\base\Component
__isset() | Checks if a property is set, i.e. defined and not null. | yii\base\Component
__set() | Sets the value of a component property. | yii\base\Component
__unset() | Sets a component property to be null. | yii\base\Component
attachBehavior() | Attaches a behavior to this component. | yii\base\Component
attachBehaviors() | Attaches a list of behaviors to the component. | yii\base\Component
behaviors() | Returns a list of behaviors that this component should behave as. | yii\base\Component
canGetProperty() | Returns a value indicating whether a property can be read. | yii\base\Component
canSetProperty() | Returns a value indicating whether a property can be set. | yii\base\Component
className() | Returns the fully qualified name of this class. | yii\base\BaseObject
detachBehavior() | Detaches a behavior from the component. | yii\base\Component
detachBehaviors() | Detaches all behaviors from the component. | yii\base\Component
ensureBehaviors() | Makes sure that the behaviors declared in behaviors() are attached to this component. | yii\base\Component
generateValidationHash() | Generates a hash code that can be used for client-side validation. | yii\captcha\CaptchaAction
getBehavior() | Returns the named behavior object. | yii\base\Component
getBehaviors() | Returns all behaviors attached to this component. | yii\base\Component
getUniqueId() | Returns the unique ID of this action among the whole application. | yii\base\Action
getVerifyCode() | Gets the verification code. | yii\captcha\CaptchaAction
hasEventHandlers() | Returns a value indicating whether there is any handler attached to the named event. | yii\base\Component
hasMethod() | Returns a value indicating whether a method is defined. | yii\base\Component
hasProperty() | Returns a value indicating whether a property is defined for this component. | yii\base\Component
init() | Initializes the action. | yii\captcha\CaptchaAction
off() | Detaches an existing event handler from this component. | yii\base\Component
on() | Attaches an event handler to an event. | yii\base\Component
run() | Runs the action. | yii\captcha\CaptchaAction
runWithParams() | Runs this action with the specified parameters. | yii\base\Action
trigger() | Triggers an event. | yii\base\Component
validate() | Validates the input to see if it matches the generated code. | yii\captcha\CaptchaAction

## Protected Methods

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Method | Description | Defined By
--- | --- | ---
afterRun() | This method is called right after `run()` is executed. | yii\base\Action
beforeRun() | This method is called right before `run()` is executed. | yii\base\Action
generateVerifyCode() | Generates a new verification code. | yii\captcha\CaptchaAction
getSessionKey() | Returns the session variable name used to store verification code. | yii\captcha\CaptchaAction
renderImage() | Renders the CAPTCHA image. | yii\captcha\CaptchaAction
renderImageByGD() | Renders the CAPTCHA image based on the code using GD library. | yii\captcha\CaptchaAction
renderImageByImagick() | Renders the CAPTCHA image based on the code using ImageMagick library. | yii\captcha\CaptchaAction
setHttpHeaders() | Sets the HTTP headers needed by image response. | yii\captcha\CaptchaAction

## Constants

Hide inherited constants

Constant | Value | Description | Defined By
--- | --- | --- | ---
REFRESH_GET_VAR | 'refresh' | The name of the GET parameter indicating whether the CAPTCHA image should be regenerated. | yii\captcha\CaptchaAction

## Property Details

$backColor public property

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

public integer $backColor = 0xFFFFFF
$fixedVerifyCode public property

The fixed verification code. When this property is set, getVerifyCode() will always return the value of this property. 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. If not set, it means the verification code will be randomly generated.

public string $fixedVerifyCode = null
$fontFile public property

The TrueType font file. This can be either a file path or path alias.

public string $fontFile = '@yii/captcha/SpicyRice.ttf'
$foreColor public property

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

public integer $foreColor = 0x2040A0
$height public property

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

public integer $height = 50
$imageLibrary public property (available since version 2.0.7)

The rendering library to use. Currently supported only 'gd' and 'imagick'. If not set, library will be determined automatically.

public string $imageLibrary = null
$maxLength public property

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

public integer $maxLength = 7
$minLength public property

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

public integer $minLength = 6
$offset public property

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

public integer $offset = -2
$padding public property

Padding around the text. Defaults to 2.

public integer $padding = 2
$testLimit public property

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).

public integer $testLimit = 3
$transparent public property

Whether to use transparent background. Defaults to false.

public boolean $transparent = false
$verifyCode public property

The verification code. This property is read-only.

public string $verifyCode = null
$width public property

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

public integer $width = 120

## Method Details

generateValidationHash() public method

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

public string generateValidationHash ( $code )
$code | string | The CAPTCHA code
return | string | A hash code generated from the CAPTCHA code

generateVerifyCode() protected method

Generates a new verification code.

protected string generateVerifyCode ( )
return | string | The generated verification code

getSessionKey() protected method

Returns the session variable name used to store verification code.

protected string getSessionKey ( )
return | string | The session variable name

getVerifyCode() public method

Gets the verification code.

public string getVerifyCode ( $regenerate = false )
$regenerate | boolean | Whether the verification code should be regenerated.
return | string | The verification code.

init() public method

Initializes the action.

public void init ( )
throws | yii\base\InvalidConfigException | if the font file does not exist.

renderImage() protected method

Renders the CAPTCHA image.

protected string renderImage ( $code )
$code | string | The verification code
return | string | Image contents
throws | yii\base\InvalidConfigException | if imageLibrary is not supported

renderImageByGD() protected method

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

protected string renderImageByGD ( $code )
$code | string | The verification code
return | string | Image contents in PNG format.

renderImageByImagick() protected method

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

protected string renderImageByImagick ( $code )
$code | string | The verification code
return | string | Image contents in PNG format.

run() public method

Runs the action.

public void run ( )

setHttpHeaders() protected method

Sets the HTTP headers needed by image response.

protected void setHttpHeaders ( )

validate() public method

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

public boolean validate ( $input, $caseSensitive )
$input | string | User input
$caseSensitive | boolean | Whether the comparison should be case-sensitive
return | boolean | Whether the input is valid