How to use Codeigniter captcha plug-in Part 1

DOWN LOAD FILES

(updated: 2 November 2009)

I have read a note in Codeigniter captcha_pi.php. You can find this file in system/plugins.
However this does not explain well. This post hopefully explains how to use this plugin. And I will show a bit different way in the next post.

I found the following two articles are very helpful and credits should go to them.

http://d.hatena.ne.jp/dix3/20080925 and http://www.blog.valenticabd.com/2008/05/23/captcha-plugin-in-codeigniter.html

The first one is in Japanese. But don’t be disappointed with it. You can find the controll code and view code at the end of the blog. These two have English notes as well.

The first step is following what a note in captcha_pi.php is telling.

Environment

I am using XAMPP for my development.
I freshly installed a codeigniter1.7.2 in hdocs and renamed as ci_captcha.
I have not added a .htaccess file nor moving application out of system folder.

Preparation

captcha folder

You need to create a folder called captcha. I created it in the same level as system folder.
ci_captcha/captcha
When you create captcha images, this is the place where all the images are saved.

Database

I used Phpmyadmin to create a database called ci_captcha.
Enter this sql.

CREATE TABLE IF NOT EXISTS `captcha` (
  `captcha_id` bigint(13) unsigned NOT NULL AUTO_INCREMENT,
  `captcha_time` int(10) unsigned NOT NULL,
  `ip_address` varchar(16) NOT NULL DEFAULT '0',
  `word` varchar(20) NOT NULL,
  PRIMARY KEY (`captcha_id`),
  KEY `word` (`word`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=71 ;

And you need to open system/application/config/database.php and modify it.

...
$db['default']['hostname'] = "localhost";
$db['default']['username'] = "root1";
$db['default']['password'] = "root";
$db['default']['database'] = "ci_captcha";
$db['default']['dbdriver'] = "mysql";
...

Autoload.php

Open system/application/config/autoload.php and change the line 44.

$autoload['libraries'] = array('database');

and line 54.

$autoload['helper'] = array('url');

Config.php

Open system/application/config/config.php and change the line 14.

$config['base_url']	= "http://127.0.0.1/ci_captcha/";

Modifying captcha_pi.php

Now open system/plugin/captcha_pi.php

By default, Captcha plugin generates 8 words in length. But if you want to change this length, in line 156 of “captcha_pi.php” there was

$defaults = array('word' => '', 'img_path' => '',
'img_url' => '', 'img_width' => '150',
'img_height' => '30', 'font_path' => '',
'expiration' => 7200);

I change to three words for my example.

$defaults = array('word' => '', 'word_length' => 3,
'img_path' => '', 'img_url' =>'',
'img_width' => '150', 'img_height' => '30',
'font_path' => '', 'expiration' => 7200);

Next, in line 226, there was

for ($i = 0; $i < 8; $i++)
</code>
which I changed to
<code>
for ($i = 0; $i < $word_length; $i++)

You need to change both line in order to work it properly.

Controller

Create a file
htdocs/ci_captcha/system/application/controller/myexample_captcha.php.
And paste the followings.

<?php if ( !defined( 'BASEPATH' ) ) exit( 'No direct script access allowed' );

class Myexample_captcha extends Controller {
  function Myexample_captcha()
  {
    parent :: Controller();
  }
  function index()
  {
    /**
     * --SQL DDL
     *
     * CREATE TABLE captcha (
     * captcha_id bigint(13) unsigned NOT NULL auto_increment,
     * captcha_time int(10) unsigned NOT NULL,
     * ip_address varchar(16) default '0' NOT NULL,
     * word varchar(20) NOT NULL,
     * PRIMARY KEY `captcha_id` (`captcha_id`),
     * KEY `word` (`word`)
     * );
     */

    $captcha_result = '';
    $data["cap_img"] = $this -> _make_captcha();
    if ( $this -> input -> post( 'submit' ) ) {
      if ( $this -> _check_capthca() ) {
        $captcha_result = 'GOOD';
      }else {
        $captcha_result = 'BAD';
      }
    }
    $data["cap_msg"] = $captcha_result;
    $this -> load -> view( 'testcaptcha_view', $data );
  }
  function _make_captcha()
  {
    $this -> load -> plugin( 'captcha' );
    $vals = array(
      'img_path' => './captcha/', // PATH for captcha ( *Must mkdir (htdocs)/captcha )
      'img_url' => 'captcha/', // URL for captcha img
      'img_width' => 200, // width
      'img_height' => 60, // height
      // 'font_path'     => '../system/fonts/2.ttf',
      // 'expiration' => 7200 ,
      );
    // Create captcha
    $cap = create_captcha( $vals );
    // Write to DB
    if ( $cap ) {
      $data = array(
        'captcha_id' => '',
        'captcha_time' => $cap['time'],
        'ip_address' => $this -> input -> ip_address(),
        'word' => $cap['word'] ,
        );
      $query = $this -> db -> insert_string( 'captcha', $data );
      $this -> db -> query( $query );
    }else {
      return "Umm captcha not work" ;
    }
    return $cap['image'] ;
  }

  function _check_capthca()
  {
    // Delete old data ( 2hours)
    $expiration = time()-7200 ;
    $sql = " DELETE FROM captcha WHERE captcha_time < ? ";
    $binds = array($expiration);
    $query = $this->db->query($sql, $binds);

    //checking input
    $sql = "SELECT COUNT(*) AS count FROM captcha WHERE word = ? AND ip_address = ? AND captcha_time > ?";
    $binds = array($_POST['captcha'], $this->input->ip_address(), $expiration);
    $query = $this->db->query($sql, $binds);
    $row = $query->row();

  if ( $row -> count > 0 )
    {
      return true;
    }
    return false;

  }

}//endofclass
/**
 * End of file example_captcha.php
 */
/**
 * Location: ./application/controllers/example_captcha.php
 */

?>

View

Create a file htdocs/ci_captcha/system/application/view/testcapcha_view.php

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
        "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
  <meta http-equiv="content-type" content="text/html; charset=utf-8" />
  <title><?php echo $title; ?></title>
  <base href="<?=base_url();?>">
  </head>
<body>
<h2>Captcha Test</h2>
<form method="post">
<?php echo $cap_img ;?>
<p><?php echo $cap_msg ;?></p>
<input type="text" name="captcha" value="" />
<input type="submit" name="submit" value="Submit">
</form>
</body>
</html>

Test drive

Now visit http://127.0.0.1/ci_captcha/index.php/myexample_captcha to see your captcha.