Add URL generation method and update to Symfony 2.1 standards

Controller/CaptchaController.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace Gregwar\CaptchaBundle\Controller;
+
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Bundle\FrameworkBundle\Controller\Controller;
+
+/**
+ * Generates a captcha via a URL
+ *
+ * @author Jeremy Livingston <jeremy.j.livingston@gmail.com>
+ */
+class CaptchaController extends Controller
+{
+    /**
+     * Action that is used to generate the captcha, save its code, and stream the image
+     *
+     * @param \Symfony\Component\HttpFoundation\Request $request
+     * @return \Symfony\Component\HttpFoundation\Response
+     */
+    public function generateCaptchaAction(Request $request)
+    {
+        $options = $this->container->getParameter('gregwar_captcha.config');
+        if (!$options['as_url']) {
+            return $this->createNotFoundException('Unable to generate a captcha via a URL without the proper configuration.');
+        }
+
+        /* @var \Gregwar\CaptchaBundle\Generator\CaptchaGenerator $generator */
+        $generator = $this->container->get('gregwar_captcha.generator');
+
+        return new Response($generator->generate($options));
+    }
+}
+

DependencyInjection/Configuration.php

@@ -9,6 +9,7 @@ class Configuration implements ConfigurationInterface
 {
     /**
      * Generates the configuration tree.
+     *
      * @return TreeBuilder
      */
     public function getConfigTreeBuilder()
@@ -26,6 +27,8 @@ class Configuration implements ConfigurationInterface
                 ->scalarNode('keep_value')->defaultValue(true)->end()
                 ->scalarNode('charset')->defaultValue('abcdefhjkmnprstuvwxyz23456789')->end()
                 ->scalarNode('as_file')->defaultValue(false)->end()
+                ->scalarNode('as_url')->defaultValue(false)->end()
+                ->scalarNode('url')->defaultValue('/generate-captcha')->end()
                 ->scalarNode('image_folder')->defaultValue('captcha')->end()
                 ->scalarNode('web_path')->defaultValue('%kernel.root_dir%/../web')->end()
                 ->scalarNode('gc_freq')->defaultValue(100)->end()

DependencyInjection/GregwarCaptchaExtension.php

@@ -4,15 +4,22 @@ namespace Gregwar\CaptchaBundle\DependencyInjection;
 
 use Symfony\Component\HttpKernel\DependencyInjection\Extension;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
-use Symfony\Component\DependencyInjection\Definition;
 use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
 use Symfony\Component\Config\FileLocator;
 
+/**
+ * Extension used to load the configuration, set parameters, and initialize the captcha view
+ *
+ * @author Gregwar <g.passault@gmail.com>
+ */
 class GregwarCaptchaExtension extends Extension
 {
+    /**
+     * @param array $configs
+     * @param \Symfony\Component\DependencyInjection\ContainerBuilder $container
+     */
     public function load(array $configs, ContainerBuilder $container)
     {
-
         $loader = new YamlFileLoader($container, new FileLocator(__DIR__.'/../Resources/config'));
         $loader->load('services.yml');
 
@@ -20,11 +27,13 @@ class GregwarCaptchaExtension extends Extension
         $config = $this->processConfiguration($configuration, $configs);
 
         $container->setParameter('gregwar_captcha.config', $config);
+        $container->setParameter('gregwar_captcha.config.image_folder', $config['image_folder']);
+        $container->setParameter('gregwar_captcha.config.web_path', $config['web_path']);
+        $container->setParameter('gregwar_captcha.config.gc_freq', $config['gc_freq']);
+        $container->setParameter('gregwar_captcha.config.expiration', $config['expiration']);
+        $container->setParameter('gregwar_captcha.config.url', $config['url']);
 
         $resources = $container->getParameter('twig.form.resources');
-        $container->setParameter('twig.form.resources',array_merge(array('GregwarCaptchaBundle::captcha.html.twig'), $resources));
+        $container->setParameter('twig.form.resources', array_merge(array('GregwarCaptchaBundle::captcha.html.twig'), $resources));
-
     }
-
 }
-

Generator/CaptchaGenerator.php

@@ -3,159 +3,126 @@
 namespace Gregwar\CaptchaBundle\Generator;
 
 use Symfony\Component\Finder\Finder;
+use Symfony\Component\HttpFoundation\Session\SessionInterface;
 
 /**
  * Generates a CAPTCHA image
  */
-class CaptchaGenerator {
+class CaptchaGenerator
+{
+    /**
+     * @var \Symfony\Component\HttpFoundation\Session\SessionInterface
+     */
+    protected $session;
 
     /**
      * Name of folder for captcha images
      * @var string
      */
-    public $imageFolder;
+    protected $imageFolder;
 
     /**
      * Absolute path to public web folder
      * @var string
      */
-    public $webPath;
+    protected $webPath;
 
     /**
-     * Frequence of garbage collection in fractions of 1
+     * Frequency of garbage collection in fractions of 1
      * @var int
      */
-    public $gcFreq;
+    protected $gcFreq;
-
-    /**
-     * Captcha Font
-     * @var string
-     */
-    public $font;
 
     /**
      * Maximum age of images in minutes
      * @var int
      */
-    public $expiration;
+    protected $expiration;
 
     /**
-     * Random fingerprint
+     * The fingerprint used to generate the image details across requests
-     * Useful to be able to regenerate exactly the same image
+     * @var array|null
-     * @var array
      */
-    public $fingerprint;
+    protected $fingerprint;
 
     /**
-     * Should fingerprint be used ?
+     * Whether this instance should use the fingerprint
-     * @var boolean
+     * @var bool
      */
-    public $use_fingerprint;
+    protected $useFingerprint;
 
     /**
-     * The captcha code
+     * The key used to store the value to the session
      * @var string
      */
-    public $value;
+    protected $key = 'captcha';
 
     /**
-     * Captcha quality
+     * @param \Symfony\Component\HttpFoundation\Session\SessionInterface $session
-     * @var int
+     * @param string $imageFolder
+     * @param string $webPath
+     * @param int $gcFreq
+     * @param int $expiration
+     * @param string $url
      */
-    public $quality;
+    public function __construct(SessionInterface $session, $imageFolder, $webPath, $gcFreq, $expiration, $url)
-
-    public function __construct($value, $imageFolder, $webPath, $gcFreq, $expiration, $font, $fingerprint, $quality)
     {
-        $this->value = $value;
+        $this->session          = $session;
         $this->imageFolder      = $imageFolder;
         $this->webPath          = $webPath;
-        $this->gcFreq = intval($gcFreq);
+        $this->gcFreq           = $gcFreq;
-        $this->expiration = intval($expiration);
+        $this->expiration       = $expiration;
-        $this->font = $font;
+        $this->url              = $url;
-        $this->fingerprint = $fingerprint;
-        $this->use_fingerprint = (bool)$fingerprint;
-        $this->quality = intval($quality);
     }
 
     /**
-     * Get the captcha embeded code
+     * Get the captcha URL, stream, or filename that will go in the image's src attribute
-     */
-    public function getCode($width = 120, $height = 40)
-    {
-        return 'data:image/jpeg;base64,'.base64_encode($this->generate($width, $height));
-    }
-
-    /**
-     * Creates a captcha image with provided dimensions
-     * and randomly executes a garbage collection
      *
-     * @param int $width
+     * @param $key
-     * @param int $height
+     * @param array $options
-     * @return string Web path to the created image
+     *
+     * @return array
      */
-    public function getFile($width = 120, $height = 40)
+    public function getCaptchaCode($key, array $options)
     {
+        $this->key = $key;
+
+        // Randomly execute garbage collection and returns the image filename
+        if ($options['as_file']) {
             if (mt_rand(1, $this->gcFreq) == 1) {
                 $this->garbageCollection();
             }
 
-        return $this->generate($width, $height, true);
+            return $this->generate($options);
         }
 
-    /**
+        // Returns the configured URL for image generation
-     * Returns a random number or the next number in the
+        if ($options['as_url']) {
-     * fingerprint
+            return $this->url;
-     */
-    public function rand($min, $max) 
-    {
-        if (!is_array($this->fingerprint)) {
-            $this->fingerprint = array();
         }
 
-        if ($this->use_fingerprint) {
+        return 'data:image/jpeg;base64,' . base64_encode($this->generate($options));
-            $value = current($this->fingerprint);
-            next($this->fingerprint);
-        } else {
-            $value = mt_rand($min, $max);
-            $this->fingerprint[] = $value;
-        }
-        return $value;
-    }
-
-    /**
-     * Get the CAPTCHA fingerprint
-     */
-    public function getFingerprint()
-    {
-        return $this->fingerprint;
-    }
-
-    /**
-     * Deletes all images in the configured folder
-     * that are older than 10 minutes
-     *
-     * @return void
-     */
-    public function garbageCollection()
-    {
-        $finder = new Finder();
-        $criteria = sprintf('<= now - %s minutes', $this->expiration);
-        $finder->in($this->webPath . '/' . $this->imageFolder)
-               ->date($criteria);
-
-        foreach($finder->files() as $file)
-        {
-            unlink($file->getPathname());
-        }
     }
 
     /**
      * Generate the image
      */
-    public function generate($width, $height, $createFile = false)
+    public function generate(array $options)
     {
-        $i = imagecreatetruecolor($width,$height);
+        $width  = $options['width'];
+        $height = $options['height'];
 
+        if ($options['keep_value'] && $this->session->has($this->key.'_fingerprint')) {
+            $this->fingerprint = $this->session->get($this->key.'_fingerprint');
+            $this->useFingerprint = true;
+        } else {
+            $this->fingerprint = null;
+            $this->useFingerprint = false;
+        }
+
+        $captchaValue = $this->getCaptchaValue($options['keep_value'], $options['charset'], $options['length']);
+
+        $i = imagecreatetruecolor($width,$height);
         $col = imagecolorallocate($i, $this->rand(0,110), $this->rand(0,110), $this->rand(0,110));
 
         imagefill($i, 0, 0, 0xFFFFFF);
@@ -171,13 +138,13 @@ class CaptchaGenerator {
         }
 
         // Write CAPTCHA text
-        $size = $width/strlen($this->value);
+        $size = $width/strlen($captchaValue);
-        $font = $this->font;
+        $font = $options['font'];
-        $box = imagettfbbox($size, 0, $font, $this->value);
+        $box = imagettfbbox($size, 0, $font, $captchaValue);
         $txt_width = $box[2] - $box[0];
         $txt_height = $box[1] - $box[7];
 
-        imagettftext($i, $size, 0, ($width-$txt_width)/2, ($height-$txt_height)/2+$size, $col, $font, $this->value);
+        imagettftext($i, $size, 0, ($width-$txt_width)/2, ($height-$txt_height)/2+$size, $col, $font, $captchaValue);
 
         // Distort the image
         $X = $this->rand(0, $width);
@@ -187,7 +154,7 @@ class CaptchaGenerator {
         $Amp=1+$this->rand(0,1000)/1000;
         $out = imagecreatetruecolor($width, $height);
 
-        for ($x=0; $x<$width; $x++)
+        for ($x=0; $x<$width; $x++) {
             for ($y=0; $y<$height; $y++) {
                 $Vx=$x-$X;
                 $Vy=$y-$Y;
@@ -215,42 +182,99 @@ class CaptchaGenerator {
 
                 imagesetpixel($out, $x, $y, $p);
             }
+        }
+
+        if ($options['keep_value']) {
+            $this->session->set($this->key.'_fingerprint', $this->fingerprint);
+        }
 
         // Renders it
-        if (!$createFile) {
+        if (!$options['as_file']) {
             ob_start();
-            imagejpeg($out, null, $this->quality);
+            imagejpeg($out, null, $options['quality']);
+
             return ob_get_clean();
-        } else {
+        }
+
         // Check if folder exists and create it if not
         if (!file_exists($this->webPath . '/' . $this->imageFolder)) {
             mkdir($this->webPath . '/' . $this->imageFolder, 0755);
         }
+        
         $filename = md5(uniqid()) . '.jpg';
         $filepath = $this->webPath . '/' . $this->imageFolder . '/' . $filename;
         imagejpeg($out, $filepath, 15);
+
         return '/' . $this->imageFolder . '/' . $filename;
     }
-    }
 
-    protected function getCol($image, $x, $y)
+    /**
+     * Generate a new captcha value or pull the existing one from the session
+     *
+     * @param bool $keepValue
+     * @param string $charset
+     * @param int $length
+     *
+     * @return mixed|string
+     */
+    protected function getCaptchaValue($keepValue, $charset, $length)
     {
-        $L = imagesx($image);
+        if ($keepValue && $this->session->has($this->key)) {
-        $H = imagesy($image);
+            return $this->session->get($this->key);
-        if ($x<0 || $x>=$L || $y<0 || $y>=$H)
-            return 0xFFFFFF;
-        else return imagecolorat($image, $x, $y);
         }
 
-    protected function getRGB($col) {
+        $value = '';
-        return array(
+        $chars = str_split($charset);
-            (int)($col >> 16) & 0xff,
+
-            (int)($col >> 8) & 0xff,
+        for ($i=0; $i < $length; $i++) {
-            (int)($col) & 0xff,
+            $value .= $chars[array_rand($chars)];
-        );
         }
 
-    function bilinearInterpolate($x, $y, $nw, $ne, $sw, $se)
+        $this->session->set($this->key, $value);
+
+        return $value;
+    }
+
+    /**
+     * Deletes all images in the configured folder
+     * that are older than the configured number of minutes
+     *
+     * @return void
+     */
+    protected function garbageCollection()
+    {
+        $finder = new Finder();
+        $criteria = sprintf('<= now - %s minutes', $this->expiration);
+        $finder->in($this->webPath . '/' . $this->imageFolder)
+            ->date($criteria);
+
+        foreach($finder->files() as $file) {
+            unlink($file->getPathname());
+        }
+    }
+
+    /**
+     * Returns a random number or the next number in the
+     * fingerprint
+     */
+    protected function rand($min, $max)
+    {
+        if (!is_array($this->fingerprint)) {
+            $this->fingerprint = array();
+        }
+
+        if ($this->useFingerprint) {
+            $value = current($this->fingerprint);
+            next($this->fingerprint);
+        } else {
+            $value = mt_rand($min, $max);
+            $this->fingerprint[] = $value;
+        }
+
+        return $value;
+    }
+
+    protected function bilinearInterpolate($x, $y, $nw, $ne, $sw, $se)
     {
         list($r0, $g0, $b0) = $this->getRGB($nw);
         list($r1, $g1, $b1) = $this->getRGB($ne);
@@ -274,5 +298,24 @@ class CaptchaGenerator {
 
         return ($r << 16) | ($g << 8) | $b;
     }
+
+    protected function getCol($image, $x, $y)
+    {
+        $L = imagesx($image);
+        $H = imagesy($image);
+        if ($x<0 || $x>=$L || $y<0 || $y>=$H) {
+            return 0xFFFFFF;
+        }
+
+        return imagecolorat($image, $x, $y);
+    }
+
+    protected function getRGB($col) {
+        return array(
+            (int)($col >> 16) & 0xff,
+            (int)($col >> 8) & 0xff,
+            (int)($col) & 0xff,
+        );
+    }
 }
 

README.md

@@ -106,13 +106,21 @@ You can use the "captcha" type in your forms this way:
     // ...
 ```
 
-Note that the generated image will be embeded in the HTML document, to avoid dealing
+Note that the generated image will, by default, be embedded in the HTML document
-with route and subrequests.
+to avoid dealing with route and subrequests.
 
 Options
 =======
 
-You can define the following type option :
+You can define the following configuration options globally:
+
+* **image_folder**: name of folder for captcha images relative to public web folder in case **as_file** is set to true (default="captcha")
+* **web_path**: absolute path to public web folder (default="%kernel.root_dir%/../web")
+* **gc_freq**: frequency of garbage collection in fractions of 1 (default=100)
+* **expiration**: maximum lifetime of captcha image files in minutes (default=60)
+* **url**: the url to use when **as_url** is set to true (default=/generate-captcha)
+
+You can define the following configuration options globally or on the CaptchaType itself:
 
 * **width**: the width of the captcha image (default=120)
 * **height**: the height of the captcha image (default=40)
@@ -122,10 +130,7 @@ You can define the following type option :
 * **font**: the font to use (default=Generator/Font/captcha.ttf)
 * **keep_value**: the value will be the same until the form is posted, even if the page is refreshed (default=true)
 * **as_file**: if set to true an image file will be created instead of embedding to please IE6/7 (default=false)
-* **image_folder**: name of folder for captcha images relative to public web folder in case **as_file** ist set to true (default="captcha")
+* **as_url**: if set to true, a URL will be used in the image tag and will handle captcha generation. This can be used in a multiple-server environment and support IE6/7 (default=false)
-* **web_path**: absolute path to public web folder (default="%kernel.root_dir%/../web")
-* **gc_freq**: frequency of garbage collection in fractions of 1 (default=100)
-* **expiration**: maximum lifetime of captcha image files in minutes (default=60)
 * **invalid_message**: error message displayed when an non-matching code is submitted (default="Bad code value")
 * **bypass_code**: code that will always validate the captcha (default=null)
 
@@ -149,10 +154,17 @@ configuration entry in your `config.yml` file:
         height: 50
         length: 6
 
-Form theming
+As URL
+============
+To use a URL to generate a captcha image, you must add the bundle's routing configuration to your app/routing.yml file:
+
+    gregwar_captcha_routing:
+        resource: "@GregwarCaptchaBundle/Resources/config/routing/routing.yml"
+
+Form Theming
 ============
 
-The widget support the standard symfony theming, see the [documentation](http://symfony.com/doc/current/book/forms.html#form-theming) for details on how to accomplish this.
+The widget support the standard Symfony theming, see the [documentation](http://symfony.com/doc/current/book/forms.html#form-theming) for details on how to accomplish this.
 
 The default rendering is:
 

Resources/config/routing/routing.yml

@@ -0,0 +1,3 @@
+gregwar_captcha.generate_captcha:
+    pattern:   %gregwar_captcha.config.url%
+    defaults:  { _controller: GregwarCaptchaBundle:Captcha:generateCaptcha }

Resources/config/services.yml

@@ -3,6 +3,19 @@ services:
     # captcha type
     captcha.type:
         class: Gregwar\CaptchaBundle\Type\CaptchaType
-        arguments: [ "@session", %gregwar_captcha.config% ]
+        arguments:
+            - @session
+            - @gregwar_captcha.generator
+            - %gregwar_captcha.config%
         tags:
             - { name: form.type, alias: captcha }
+
+    gregwar_captcha.generator:
+        class: Gregwar\CaptchaBundle\Generator\CaptchaGenerator
+        arguments:
+            - @session
+            - %gregwar_captcha.config.image_folder%
+            - %gregwar_captcha.config.web_path%
+            - %gregwar_captcha.config.gc_freq%
+            - %gregwar_captcha.config.expiration%
+            - %gregwar_captcha.config.url%

Type/CaptchaType.php

@@ -2,20 +2,16 @@
 
 namespace Gregwar\CaptchaBundle\Type;
 
-use Symfony\Component\HttpFoundation\Session\Session;
+use Symfony\Component\HttpFoundation\Session\SessionInterface;
-use Symfony\Component\DependencyInjection\ContainerInterface;
-
 use Symfony\Component\Form\FormView;
 use Symfony\Component\Form\FormInterface;
 use Symfony\Component\Form\AbstractType;
-use Symfony\Component\Form\Exception\FormException;
 use Symfony\Component\Form\FormBuilderInterface;
 use Symfony\Component\OptionsResolver\OptionsResolverInterface;
-use Symfony\Component\Form\FormViewInterface;
+use Symfony\Component\Form\FormEvents;
 
 use Gregwar\CaptchaBundle\Validator\CaptchaValidator;
 use Gregwar\CaptchaBundle\Generator\CaptchaGenerator;
-use Gregwar\CaptchaBundle\DataTransformer\EmptyTransformer;
 
 /**
  * Captcha type
@@ -24,6 +20,16 @@ use Gregwar\CaptchaBundle\DataTransformer\EmptyTransformer;
  */
 class CaptchaType extends AbstractType
 {
+    /**
+     * @var \Symfony\Component\HttpFoundation\Session\SessionInterface
+     */
+    protected $session;
+
+    /**
+     * @var \Gregwar\CaptchaBundle\Generator\CaptchaGenerator
+     */
+    protected $generator;
+
     /**
      * Options
      * @var array
@@ -36,94 +42,67 @@ class CaptchaType extends AbstractType
      */
     private $key = 'captcha';
 
-    public function __construct(Session $session, $config)
+    /**
+     * @param \Symfony\Component\HttpFoundation\Session\SessionInterface $session
+     * @param \Gregwar\CaptchaBundle\Generator\CaptchaGenerator $generator
+     * @param array $options
+     */
+    public function __construct(SessionInterface $session, CaptchaGenerator $generator, $options)
     {
         $this->session      = $session;
-        $this->options = $config;
+        $this->generator    = $generator;
+        $this->options      = $options;
     }
 
+    /**
+     * @param \Symfony\Component\Form\FormBuilderInterface $builder
+     * @param array $options
+     */
     public function buildForm(FormBuilderInterface $builder, array $options)
     {
         $this->key = $builder->getForm()->getName();
 
-        $builder->addValidator(
+        $validator = new CaptchaValidator($this->session, $this->key, $options['invalid_message'], $options['bypass_code']);
-            new CaptchaValidator($this->session,
+        $builder->addEventListener(FormEvents::POST_BIND, array($validator, 'validate'));
-                                 $this->key,
-                                 $options['invalid_message'],
-                                 $options['bypass_code'])
-        );
     }
 
+    /**
+     * @param \Symfony\Component\Form\FormView $view
+     * @param \Symfony\Component\Form\FormInterface $form
+     * @param array $options
+     */
     public function buildView(FormView $view, FormInterface $form, array $options)
     {
-        $fingerprint = null;
+        $view->vars = array_merge($view->vars, array(
-
-        if ($options['keep_value'] && $this->session->has($this->key.'_fingerprint')) {
-            $fingerprint = $this->session->get($this->key.'_fingerprint');
-        }
-
-        $generator = new CaptchaGenerator($this->generateCaptchaValue(),
-                                          $options['image_folder'],
-                                          $options['web_path'],
-                                          $options['gc_freq'],
-                                          $options['expiration'],
-                                          $options['font'],
-                                          $fingerprint,
-                                          $options['quality']);
-
-        if ($options['as_file']) {
-            $captchaCode = $generator->getFile($options['width'], $options['height']);
-        } else {
-            $captchaCode = $generator->getCode($options['width'], $options['height']);
-        }
-
-        if ($options['keep_value']) {
-            $this->session->set($this->key.'_fingerprint', $generator->getFingerprint());
-        }
-
-        $fieldVars = array(
             'captcha_width'     => $options['width'],
             'captcha_height'    => $options['height'],
-            'captcha_code'      => $captchaCode,
+            'captcha_code'      => $this->generator->getCaptchaCode($this->key, $options),
             'value'             => '',
-        );
+        ));
-
-        foreach($fieldVars as $name => $value){
-            $view->set($name,$value);    
-        }
     }
 
+    /**
+     * @param \Symfony\Component\OptionsResolver\OptionsResolverInterface $resolver
+     */
     public function setDefaultOptions(OptionsResolverInterface $resolver)
     {
         $this->options['property_path'] = false;
         $resolver->setDefaults($this->options);
     }
 
+    /**
+     * @return string
+     */
     public function getParent()
     {
         return 'text';
     }
 
+    /**
+     * @return string
+     */
     public function getName()
     {
         return 'captcha';
     }
-
-    private function generateCaptchaValue()
-    {
-        if (!$this->options['keep_value'] || !$this->session->has($this->key)) {
-            $value = '';
-            $chars = str_split($this->options['charset']);
-
-            for ($i=0; $i<$this->options['length']; $i++) {
-                $value.= $chars[array_rand($chars)];
-            }
-
-            $this->session->set($this->key, $value);
-        } else {
-            $value = $this->session->get($this->key);
-        }
-
-        return $value;
-    }
 }

Validator/CaptchaValidator.php

@@ -2,20 +2,19 @@
 
 namespace Gregwar\CaptchaBundle\Validator;
 
-use Symfony\Component\Form\FormValidatorInterface;
+use Symfony\Component\HttpFoundation\Session\SessionInterface;
-use Symfony\Component\HttpFoundation\Session\Session;
-use Symfony\Component\Form\FormInterface;
 use Symfony\Component\Form\FormError;
+use Symfony\Component\Form\FormEvent;
 
 /**
  * Captcha validator
  *
  * @author Gregwar <g.passault@gmail.com>
  */
-class CaptchaValidator implements FormValidatorInterface
+class CaptchaValidator
 {
     /**
-     * Session
+     * @var \Symfony\Component\HttpFoundation\Session\SessionInterface
      */
     private $session;
 
@@ -34,7 +33,13 @@ class CaptchaValidator implements FormValidatorInterface
      */
     private $bypassCode;
 
-    public function __construct(Session $session, $key, $invalidMessage, $bypassCode)
+    /**
+     * @param \Symfony\Component\HttpFoundation\Session\SessionInterface $session
+     * @param string $key
+     * @param string $invalidMessage
+     * @param string|null $bypassCode
+     */
+    public function __construct(SessionInterface $session, $key, $invalidMessage, $bypassCode)
     {
         $this->session          = $session;
         $this->key              = $key;
@@ -42,8 +47,13 @@ class CaptchaValidator implements FormValidatorInterface
         $this->bypassCode       = $bypassCode;
     }
 
-    public function validate(FormInterface $form)
+    /**
+     * @param FormEvent $event
+     */
+    public function validate(FormEvent $event)
     {
+        $form = $form = $event->getForm();
+
         $code = $form->getData();
         $expectedCode = $this->getExpectedCode();
 
@@ -54,34 +64,46 @@ class CaptchaValidator implements FormValidatorInterface
 
         $this->session->remove($this->key);
 
-        if ($this->session->has($this->key.'_fingerprint')) {
+        if ($this->session->has($this->key . '_fingerprint')) {
-            $this->session->remove($this->key.'_fingerprint');
+            $this->session->remove($this->key . '_fingerprint');
         }
     }
 
     /**
      * Retrieve the expected CAPTCHA code
+     *
+     * @return mixed|null
      */
-    private function getExpectedCode()
+    protected function getExpectedCode()
     {
         if ($this->session->has($this->key)) {
             return $this->session->get($this->key);
         }
+
         return null;
     }
 
     /**
      * Process the codes
+     *
+     * @param $code
+     *
+     * @return string
      */
-    private function niceize($code)
+    protected function niceize($code)
     {
         return strtr(strtolower($code), 'oil', '01l');
     }
 
     /**
      * Run a match comparison on the provided code and the expected code
+     *
+     * @param $code
+     * @param $expectedCode
+     *
+     * @return bool
      */
-    private function compare($code, $expectedCode)
+    protected function compare($code, $expectedCode)
     {
         return ($expectedCode && is_string($expectedCode) && $this->niceize($code) == $this->niceize($expectedCode));
     }