Implement CAPTCHA In CodeIgniter

CAPTCHA is a randomly generated string (or a set of images) that appears when verification is required. It is an essential requirement for cutting down the spam at a website. In many cases, it is the only line of defense a website has against bots that spam websites.

In this tutorial, I will demonstrate how you can easily implement CAPTCHA in your CodeIgniter projects.

Create Controller

The process starts with the creation of the Controller.

Create a file named captcha.php in the Controller folder. Open the file in your code editor and add the following code to it:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

<?php   defined('BASEPATH') OR exit('your exit message');   class Captcha extends CI_Controller   {      function __construct()      {          parent::__construct();          $this->load->helper('captcha');      }      public function index()      {          if ($this->input->post('submit')) {              $captcha_insert = $this->input->post('captcha');              $contain_sess_captcha = $this->session->userdata('valuecaptchaCode');              if ($captcha_insert === $contain_sess_captcha) {                  echo 'Success';              } else {                  echo 'Failure';              }          }          $config = array(              'img_url' => base_url() . 'image_for_captcha/',              'img_path' => 'image_for_captcha/',              'img_height' => 45,              'word_length' => 5,              'img_width' => '45',              'font_size' => 10          );          $captcha = create_captcha($config);          $this->session->unset_userdata('valuecaptchaCode');          $this->session->set_userdata('valuecaptchaCode', $captcha['word']);          $data['captchaImg'] = $captcha['image'];          $this->load->view('captcha/index', $data);      }      public function refresh()      {          $config = array(              'img_url' => base_url() . 'image_for_captcha/',              'img_path' => 'image_for_captcha/',              'img_height' => 45,              'word_length' => 5,              'img_width' => '45',              'font_size' => 10          );          $captcha = create_captcha($config);          $this->session->unset_userdata('valuecaptchaCode');          $this->session->set_userdata('valuecaptchaCode', $captcha['word']);          echo $captcha['image'];      }   }

Code Explanation

Here is a brief explanation of the various components of the Controller code:

Load CAPTCHA Helper  

1	$this->load->helper('captcha');

Form Submission

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17

if ($this->input->post('submit')) {              $captcha_insert = $this->input->post('captcha');              $contain_sess_captcha = $this->session->userdata('valuecaptchaCode');              if ($captcha_insert === $contain_sess_captcha) {                  echo 'Success';              } else {                  echo 'Failure';              }          }

CAPTCHA Configuration

1 2 3 4 5 6 7 8 9 10 11

'img_url' => base_url() . 'image_for_captcha/',              'img_path' => 'image_for_captcha/',              'img_height' => 45,              'word_length' => 5,              'img_width' => '45',              'font_size' => 10

Refresh CAPTCHA

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39

public function refresh()      {          $config = array(              'img_url' => base_url() . 'image_for_captcha/',              'img_path' => 'image_for_captcha/',              'img_height' => 45,              'word_length' => 5,              'img_width' => '45',              'font_size' => 10          );          $captcha = create_captcha($config);          $this->session->unset_userdata('valuecaptchaCode');          $this->session->set_userdata('valuecaptchaCode', $captcha['word']);          echo $captcha['image'];      }   Unset Previous CAPTCHA and Set a New One   $this->session->unset_userdata('valuecaptchaCode');   $this->session->set_userdata('valuecaptchaCode', $captcha['word']);   Load the View      $this->load->view('captcha/index', $data);

Create the View

The next step is the creation of the View. for this, create a folder in the View folder. Go into the folder and create another folder with the name captcha. inside this folder, create a file named index.php. Add the following code to the file:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

<!DOCTYPE html>   <html>   <head>      <title>Implement Captcha in Codeigniter using helper</title>      <script>          $(document).ready(function(){              $('.captcha-refresh').on('click', function(){                  $.get('<?php echo base_url().'captcha/refresh'; ?>', function(data){                      $('#image_captcha').html(data);                  });              });          });      </script>      <script src="<?php echo base_url(); ?>/js/jquery.js"></script>   </head>   <body>   <p id="image_captcha"><?php echo $captchaImg; ?></p>   <a href="javascript:void(0);" class="captcha-refresh" ><img src="<?php echo base_url().'images/refresh.png'; ?>"/></a>   <form method="post">      <input type="text" name="captcha" value=""/>      <input type="submit" name="submit" value="SUBMIT"/>   </form>   </body>   </html>

Another Method of Calling CAPTCHA with Validation

Here is another method that is used to call in CAPTCHA through CodeIgniter helper and then validate it.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97

<?php   class Captcha extends CI_Controller   {      public function index()      {          $this->load->helper(array('form', 'url', 'captcha'));          $this->load->library('form_validation');          $this->form_validation->set_error_delimiters('<div class="error">', '</div>');          $this->form_validation->set_rules('username', 'Username', 'trim|required|xss_clean');          $this->form_validation->set_rules('password', 'Password', 'trim|required|xss_clean|callback_check_database');          $this->form_validation->set_rules('captcha', 'Captcha', 'callback_validate_captcha');          if ($this->form_validation->run() == FALSE) {              $original_string = array_merge(range(0, 9), range('a', 'z'), range('A', 'Z'));              $original_string = implode("", $original_string);              $captcha = substr(str_shuffle($original_string), 0, 6);                  $vals = array(                  'word' => $captcha,                  'img_path' => 'image_for_captcha/',                  'font_size' => 10,                  'img_width' => 150,                  'img_height' => 50,                  'expiration' => 7200              );              $cap = create_captcha($vals);              $data['image'] = $cap['image'];              if (file_exists(BASEPATH . "../captcha/" . $this->session->userdata['image']))                  unlink(BASEPATH . "../captcha/" . $this->session->userdata['image']);              $this->session->set_userdata(array('captcha' => $captcha, 'image' => $cap['time'] . '.jpg'));              $this->load->view('index_index', $data);          } else {              if (file_exists(BASEPATH . "../captcha/" . $this->session->userdata['image']))                  unlink(BASEPATH . "../captcha/" . $this->session->userdata['image']);              $this->session->unset_userdata('captcha');              $this->session->unset_userdata('image');              redirect('home', 'refresh');          }      }          public function validate_captcha()      {          if ($this->input->post('captcha') != $this->session->userdata['captcha']) {              $this->form_validation->set_message('validate_captcha', 'Cpatcha Code is wrong');              return false;          } else {              return true;          }      }   }

Conclusion

In this tutorial, I discussed how you could easily integrate CAPTCHA into your CodeIgniter projects. If you need help. just drop a comment and I will get back to you.