Changeset 3015

Timestamp:

07/09/08 15:45:47 (7 weeks ago)

Author:

Geert

Message:

Revamped Captcha library big time.

• Each Captcha style has its own driver which generates and renders a Captcha challenge. The output could be an image, but could be anything else since html output is allowed. I included a Riddle driver to give you an idea of the flexibility.
  
• Config groups supported.
  
• More polished coding style and structure in general.
  
• Still needs work on the image generating part. Mostly GD2 stuff, and quite some copy and paste from the previous version. Any help appreciated. :)
  

Location:

trunk/system

Files:

• config/captcha.php (modified) (1 diff)
• controllers/captcha.php (modified) (2 diffs)
• libraries/Captcha.php (modified) (2 diffs)
• libraries/Pagination.php (modified) (3 diffs)

trunk/system/config/captcha.php

@@ -1 +1 @@
 <?php defined('SYSPATH') or die('No direct access allowed.');
 /**
- * @package  Captcha
+ * @package  Core
  *
- * Configure the Captcha
- * Custom styles can be added by extending the Captcha class
+ * Captcha configuration is defined in groups which allows you to easily switch
+ * between different Captcha settings for different forms on your website.
+ * Note: all groups inherit and overwrite the default group.
+ *
+ * Group Options:
+ *  style           - Style driver
+ *  width           - Width of the Captcha image
+ *  height          - Height of the Captcha image
+ *  complexity      - Difficulty of the Captcha, concrete usage depends on chosen style
+ *  background_path - Path to folder in which background image reside
+ *  background_file - Image file name
+ *  font_path       - Path to folder in which fonts reside
+ *  font_file       - Font file name
  */
-
-/**
- * Width and height of the Captcha image.
- * These settings are ignored if using a background image.
- */
-$config['width']  = 150;
-$config['height'] = 50;
-
-/**
- * Captcha style to use. Default is 'basic' and is only for testing as it
- * does not require any truetype fonts installed.
- * 'standard' is the recommended style. A font must be supplied. A background
- * image is optional.
- * 'alphasoup' is an alternative style. A font must be supplied.
- * 'math' is a 'solve the question' style.
- * A font must be supplied. A background image is optional.
- * Custom styles can be added easily by extending the library.
- */
-$config['style'] = 'standard';
-
-/**
- * Number of characters to use for the Captcha (4 or 5 recommended).
- * This setting is ignored if using style 'math'.
- */
-$config['num_chars'] = 4;
-
-/**
- * Path to font files. Example: 'application/fonts/'.
- * If using 'standard' style, you must supply a valid truetype font file.
- */
-$config['font_path'] = SYSPATH.'fonts/';
-
-/**
- * Name of the font, with the file extension. Case sensitive.
- */
-$config['font_name'] = 'DejaVuSerif.ttf';
-
-/**
- * Background image. Example: 'application/images/pattern.jpg'.
- * The dimensions of this image will be used.
- */
-$config['background_image'] = '';
+$config['default'] = array
+(
+    'style'           => 'riddle',
+    'width'           => 150,
+    'height'          => 50,
+    'complexity'      => 4,
+    'background_path' => '',
+    'background_file' => '',
+    'font_path'       => SYSPATH.'fonts/',
+    'font_file'       => 'DejaVuSerif.ttf',
+);

trunk/system/controllers/captcha.php

@@ -1 +1 @@
 <?php defined('SYSPATH') or die('No direct script access.');
 /**
- * Allows a CAPTCHA image to be displayed dynamically.
- * Captcha library is called to output the image.
- *
- *
- * Usage: Call the captcha controller from a view.
- *        `echo html::image(url::site().'captcha');`
+ * Outputs the dynamic Captcha image.
+ * Usage: Call the Captcha controller from a view, e.g.
+ *        <img src="<?php echo url::site('captcha') ?>" />
  *
  * $Id$
  *
- * @package    Core
+ * @package    Captcha
  * @author     Kohana Team
  * @copyright  (c) 2007-2008 Kohana Team
@@ -17 +14 @@
 class Captcha_Controller extends Controller {
 
-    public $session;
-    public $captcha;
-
-    protected $captcha_code;
-
     public function index()
     {
-        $this->session = Session::instance();
-        $this->captcha = new Captcha;
-
-        // Create and store a random captcha string
-        $this->captcha_code = $this->create_code();
-        $this->captcha->set_code($this->captcha_code);
-        $this->session->set('captcha_code', $this->captcha_code);
-
-        // Output the image
-        $this->captcha->render();
-    }
-
-    private function create_code()
-    {
-        if (Config::item('captcha.style') === 'math')
-        {
-            $code = (string) mt_rand(101, 991);
-        }
-        else
-        {
-            $code = text::random('distinct', Config::item('captcha.num_chars'));
-        }
-
-        return $code;
+        // Output the Captcha challenge resource (no html)
+        $captcha = new Captcha;
+        $captcha->render(FALSE);
     }
 

trunk/system/libraries/Captcha.php

@@ -12 +12 @@
 class Captcha_Core {
 
-    // Config
-    protected $font_path        = '';
-    protected $font_name        = '';
-    protected $width            = 150;
-    protected $height           = 50;
-    protected $background_image = '';
-    protected $style            = 'basic';
-    protected $num_chars        = 4;
+    // Style-dependent Captcha driver
+    protected $driver;
 
-    // Class internal variables
-    protected $image;
-    protected $color_black;
-    protected $color_white;
-    protected $spacing;
-    protected $captcha_code;
-    protected $numerals = array('zero', 'one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine');
+    // Config values
+    public static $config = array
+    (
+        'style'      => 'basic',
+        'width'      => 150,
+        'height'     => 50,
+        'complexity' => 4,
+        'background' => '',
+        'font'       => '',
+    );
+
+    // The Captcha challenge answer, the text the user is supposed to enter
+    public static $answer;
 
     /**
-     * Creates a new Captcha instance.
+     * Constructs a new Captcha object.
      *
      * @throws  Kohana_Exception
-     * @param   array  configuration
+     * @param   string  configuration settings
      * @return  void
      */
     public function __construct($config = array())
     {
-        static $check;
+        static $gd2_check;
 
-        // Check that a suitable GD2 library is available
-        ($check === NULL) and $check = function_exists('imagegd2');
-
-        if ($check === FALSE)
+        // We need GD2 exclusively
+        if ($gd2_check === NULL AND ($gd2_check = function_exists('imagegd2')) === FALSE)
             throw new Kohana_Exception('captcha.requires_GD2');
 
-        // Load configuration
-        $config += Config::item('captcha', FALSE, FALSE);
-
-        $this->initialize($config);
-
-        // If using a background image, check if it exists.
-        if ($this->background_image)
+        // No custom config group name given
+        if ( ! isset($config['group']))
         {
-            if ( ! file_exists($this->background_image))
-                throw new Kohana_Exception('captcha.file_not_found', $this->background_image);
+            $config['group'] = 'default';
         }
 
-        // If using a font, check if it exists.
-        if ($this->font_name)
+        // Load and validate config group
+        if ( ! is_array($group_config = Config::item('captcha.'.$config['group'])))
+            throw new Kohana_Exception('captcha.undefined_group', $config['group']);
+
+        // All captcha config groups inherit default config group
+        if ($config['group'] !== 'default')
         {
-            if ( ! file_exists($this->font_path.$this->font_name))
-                throw new Kohana_Exception('captcha.file_not_found', $this->font_path.$this->font_name);
+            // Load and validate default config group
+            if ( ! is_array($default_config = Config::item('captcha.default')))
+                throw new Kohana_Exception('captcha.undefined_group', 'default');
+
+            // Merge config group with default config group
+            $group_config += $default_config;
         }
+
+        // Merge custom config items with config group
+        $config += $group_config;
+
+        // Assign config values to the object
+        foreach ($config as $key => $value)
+        {
+            if (array_key_exists($key, self::$config))
+            {
+                self::$config[$key] = $value;
+            }
+        }
+
+        // If using a background image, check if it exists
+        if ( ! empty($config['background_file']))
+        {
+            self::$config['background'] = str_replace('\\', '/', realpath($config['background_path'])).'/'.$config['background_file'];
+
+            if ( ! file_exists(self::$config['background']))
+                throw new Kohana_Exception('captcha.file_not_found', self::$config['background']);
+        }
+
+        // If using a font, check if it exists
+        if ( ! empty($config['font_file']))
+        {
+            self::$config['font'] = str_replace('\\', '/', realpath($config['font_path'])).'/'.$config['font_file'];
+
+            if ( ! file_exists(self::$config['font']))
+                throw new Kohana_Exception('captcha.file_not_found', self::$config['font']);
+        }
+
+        // Set driver name
+        $driver = 'Captcha_'.ucfirst($config['style']).'_Driver';
+
+        // Load the driver
+        if ( ! Kohana::auto_load($driver))
+            throw new Kohana_Exception('core.driver_not_found', $config['style'], get_class($this));
+
+        // Initialize the driver
+        $this->driver = new $driver();
+
+        // Validate the driver
+        if ( ! ($this->driver instanceof Captcha_Driver))
+            throw new Kohana_Exception('core.driver_implements', $type, get_class($this), 'Captcha_Driver');
+
+        // Generate a new Captcha challenge
+        self::$answer = (string) $this->driver->generate_challenge();
+
+        // Store the answer in a session
+        Session::instance()->set('captcha_answer', self::$answer);
 
         Log::add('debug', 'Captcha Library initialized');
@@ -69 +119 @@
 
     /**
-     * Sets or overwrites config values.
+     * Validates a Captcha answer.
      *
-     * @param   array  configuration
-     * @return  void
+     * @param   string   captcha answer
+     * @return  boolean
      */
-    public function initialize($config)
+    public static function valid($answer)
     {
-        // Assign config values to the object
-        foreach ($config as $key => $value)
-        {
-            if (property_exists($this, $key))
-            {
-                $this->$key = $value;
-            }
-        }
+        return (strtoupper($answer) === strtoupper(Session::instance()->get('captcha_answer')));
     }
 
     /**
-     * Sets the Captcha code to use.
+     * Output the Captcha challenge.
      *
-     * @param   string  captcha code generated in captcha controller
-     * @return  void
+     * @param   boolean  TRUE to output html, e.g. <img src="#" />
+     * @return  mixed
      */
-    public function set_code($str)
+    public function render($html = TRUE)
     {
-        $this->captcha_code = (string) $str;
+        return $this->driver->render($html);
     }
 
     /**
-     * Generates the Captcha image.
+     * Magically outputs the Captcha challenge.
      *
-     * @return  void
+     * @return  mixed
      */
-    public function render()
+    public function __toString()
     {
-        // If extending the class with a custom Captcha function, name it 'xyz_captcha'.
-        // Style 'xyz' must be added to config. Now call the method that implements the Captcha.
-        $this->{$this->style.'_captcha'}();
-
-        // Tell browser what to expect
-        // TODO: make this automatic
-        // header('Content-Type: image/jpeg');
-        header('Content-Type: image/png');
-
-        // Output the captcha image
-        // imagejpeg($this->image);
-        imagepng($this->image);
-
-        // Free up resources
-        imagedestroy($this->image);
-    }
-
-    /**
-     * Validates the Captcha code against session Captcha code
-     *
-     * @param   string   captcha code text
-     * @return  boolean
-     */
-    public static function valid_captcha($str)
-    {
-        return (strtoupper($str) === strtoupper(Session::instance()->get('captcha_code')));
-    }
-
-    /**
-     * Creates image resource and allocates some basic colors.
-     * If a background image is supplied, the image dimensions are used.
-     *
-     * @return  void
-     */
-    protected function img_create()
-    {
-        if ($this->background_image)
-        {
-            // TODO: create from any valid image
-            $this->image = imagecreatefromjpeg($this->background_image);
-            $this->color_white = imagecolorallocate($this->image, 255, 255, 255);
-
-            // Get the background image dimensions
-            $this->width  = imagesx($this->image);
-            $this->height = imagesy($this->image);
-        }
-        else
-        {
-            $this->image = imagecreatetruecolor($this->width, $this->height);
-            $this->color_white = imagecolorallocate($this->image, 255, 255, 255);
-
-            // Fill the image with a colored gradient (use random colors, but try not to obscure text)
-            $left_color  = array(mt_rand(100,255), 0, 255);
-            $right_color = array(100, 100, mt_rand(100,0));
-            $this->img_color_gradient($this->image, 0, 0, $this->height, $this->width, $left_color, $right_color);
-        }
-    }
-
-    /**
-     * Allocates a background color to image.
-     *
-     * @param   array  GD image color identifier
-     * @return  void
-     */
-    protected function img_background($color)
-    {
-        imagefill($this->image, 0, 0, $color);
-    }
-
-    /**
-     * Draws a very basic Captcha image.
-     * Requires only GD. Useful for testing or if you can't use truetype fonts.
-     *
-     * @return  void
-     */
-    protected function basic_captcha()
-    {
-        $this->image       = imagecreate($this->width, $this->height);
-        $this->color_white = imagecolorallocate($this->image, 255, 255, 255);
-        $this->color_black = imagecolorallocate($this->image, 0, 0, 0);
-
-        imagestring($this->image, 5, 50, 15, $this->captcha_code, $this->color_black);
-    }
-
-    /**
-     * Draws the standard Captcha image:
-     * Requires GD with freetype and available truetype compatible font files.
-     *
-     * @param   none
-     * @return  void
-     */
-    protected function standard_captcha()
-    {
-        $this->img_create();
-
-        $font = $this->font_path.$this->font_name;
-        $this->calculate_spacing();
-
-        // Draw each Captcha character with varying attributes
-        for ($i = 0, $strlen = strlen($this->captcha_code); $i < $strlen; $i++)
-        {
-            // Allocate random color, size and rotation attributes to text
-            $text_color = imagecolorallocate($this->image, mt_rand(0, 100), mt_rand(0, 100), mt_rand(0, 100));
-            $angle = mt_rand(-40, 40);
-
-            // Make first char angle inward
-            if ($i === 0)
-            {
-                $angle = -abs($angle);
-            }
-            // Make last char angle inward
-            if ($i === ($this->num_chars - 1))
-            {
-                $angle = abs($angle);
-            }
-
-            // Scale the character size on image height
-            $font_size = mt_rand($this->height - 20, $this->height - 12);
-            $char_details = imageftbbox($font_size, $angle, $font, $this->captcha_code[$i], array());
-
-            // Calculate character starting coordinates
-            $iX = $this->spacing / 4 + $i * $this->spacing;
-            $char_height = $char_details[2] - $char_details[5];
-            $iY = $this->height / 2 + $char_height / 4;
-
-            // Write text character to image
-            imagefttext($this->image, $font_size, $angle, $iX, $iY, $text_color, $font, $this->captcha_code[$i], array());
-        }
-    }
-
-    /**
-     * Draws the alphasoup Captcha image:
-     * Requires GD with freetype and available truetype compatible font files.
-     *
-     * @param   none
-     * @return  void
-     */
-    protected function alphasoup_captcha()
-    {
-        $this->img_create();
-        $font = $this->font_path.$this->font_name;
-        $text_color = imagecolorallocate($this->image, mt_rand(0, 100), mt_rand(0, 100), mt_rand(0, 100));
-        $color_limit = mt_rand(96, 160);
-        $fill_color = imageColorAllocate($this->image, mt_rand($color_limit, 255), mt_rand($color_limit, 255), mt_rand($color_limit, 255));
-        imageFilledRectangle($this->image, 0, 0, $this->width, $this->height, $fill_color);
-        $font_width = imageFontWidth(10);
-        $chars = 'ABCDEFGHIJKLMNO';
-
-        for($loop = 0; $loop < 20; $loop++)
-        {
-            $text_color = imageColorAllocate($this->image, mt_rand($color_limit + 8, 255), mt_rand($color_limit + 8, 255), mt_rand($color_limit + 8, 255));
-            $char = substr($chars, mt_rand(0, 15), 1);
-            imageTTFtext($this->image, mt_rand(23, 27), mt_rand(160, 200), mt_rand(-10, $this->width + 10), mt_rand(-10, 60), $text_color, $font, $char);
-        }
-
-        $this->calculate_spacing();
-        // Draw each Captcha character with varying attributes
-        for ($i = 0, $strlen = strlen($this->captcha_code); $i < $strlen; $i++)
-        {
-            // Allocate random color, size and rotation attributes to text
-            $text_color = imagecolorallocate($this->image, mt_rand(0, 100), mt_rand(0, 100), mt_rand(0, 100));
-            $angle = mt_rand(-40, 40);
-
-            // Make first char angle inward
-            if ($i === 0)
-            {
-                $angle = -abs($angle);
-            }
-            // Make last char angle inward
-            if ($i === ($this->num_chars - 1))
-            {
-                $angle = abs($angle);
-            }
-
-            // Scale the character size on image height
-            $font_size = mt_rand($this->height - 20, $this->height - 12);
-            $char_details = imageftbbox($font_size, $angle, $font, $this->captcha_code[$i], array());
-
-            // Calculate character starting coordinates
-            $iX = $this->spacing / 4 + $i * $this->spacing;
-            $char_height = $char_details[2] - $char_details[5];
-            $iY = $this->height / 2 + $char_height / 4;
-
-            // Write text character to image
-            imagefttext($this->image, $font_size, $angle, $iX, $iY, $text_color, $font, $this->captcha_code[$i], array());
-        }
-
-    }
-
-    /**
-     * Draws the math riddle Captcha image.
-     * Requires GD with freetype and available truetype compatible font files.
-     *
-     * @return  void
-     */
-    protected function math_captcha()
-    {
-        $answer = Session::instance()->get('captcha_code');
-
-        // Convert to numeral
-        $numeral = $this->numerals[substr($answer, -1)];
-
-        // Subtract last digit from answer
-        $number = substr($answer, 0, 2).'0';
-
-        // $number plus $numeral equals $answer
-        $text = $number.' + '.$numeral.' = ';
-        $this->img_create();
-        $font = $this->font_path.$this->font_name;
-
-        // Scale the font size to image height
-        $font_size = $this->height / 3;
-        $text_details = imageftbbox($font_size, 0, $font, $text, array());
-        $iX = 5;
-        $iY = ($this->height / 2) + 5;
-
-        imagefttext($this->image, $font_size, 0, $iX, $iY, $this->color_white, $font, $text, array());
-    }
-
-    /**
-     * Calculates letter spacing for truetype font characters.
-     *
-     * @return  integer
-     */
-    protected function calculate_spacing()
-    {
-        return $this->spacing = (int) $this->width / $this->num_chars;
-    }
-
-    /**
-     * Fills the image with a colored gradient.
-     *
-     * @param   resource  gd image resource identifier
-     * @param   integer   start X position
-     * @param   integer   start Y position
-     * @param   integer   height of fill in pixels
-     * @param   integer   width of fill in pixels
-     * @param   resource  gd image color identifier for left of image
-     * @param   resource  gd image color identifier for right of image
-     * @return  void
-     */
-    protected function img_color_gradient($image, $x1, $y1, $height, $width, $left_color, $right_color)
-    {
-        $color0 = ($left_color[0] - $right_color[0]) / $width;
-        $color1 = ($left_color[1] - $right_color[1]) / $width;
-        $color2 = ($left_color[2] - $right_color[2]) / $width;
-
-        for ($i = 0; $i <= $width; $i++)
-        {
-            $red   = $left_color[0] - floor($i * $color0);
-            $green = $left_color[1] - floor($i * $color1);
-            $blue  = $left_color[2] - floor($i * $color2);
-            $col   = imagecolorallocate($this->image, $red, $green, $blue);
-
-            imageline($this->image, $x1 + $i, $y1, $x1 + $i, $y1 + $height, $col);
-        }
+        return $this->render();
     }
 

trunk/system/libraries/Pagination.php

@@ -47 +47 @@
 
     /**
-     * Constructs the Pagination object.
+     * Constructs a new Pagination object.
      *
      * @param   array  configuration settings
@@ -69 +69 @@
      * Sets config values.
      *
+     * @throws  Kohana_Exception
      * @param   array  configuration settings
      * @return  void
@@ -198 +199 @@
 
     /**
-     * Magically converts pagination object to string.
+     * Magically converts Pagination object to string.
      *
      * @return  string  pagination html