Earlier
it was a plugin for captcha in Codigniter. Now its very with new version to embed captcha in codeigniter. Captcha helper is available in new codeigniter version

Controller
class Parents extends CI_Controller {



    function __construct() {

        parent::__construct();

        $this->load->model('parent_model');

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

    }



    function signup() {

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

        $vals = array(

            'img_path' => './captcha/',

            'img_url' => base_url() . 'captcha/'

        );

        $cap = create_captcha($vals);

        $details['image'] = $cap['image'];

        $details['imgName'] = $cap['time'];

        $details['captchaId'] = $this->parent_model->createCaptcha($cap);

        $this->load->view('signup', $details);

    }

    function checkCaptcha($captcha, $captchaId) {

        $accuracy = $this->parent_model->checkCaptchaAccuracy($captcha, $captchaId);

        if ($accuracy > 0) {

            echo '1';

        } else {

            echo '0';

        }

    }





}



Model
class Parent_Model extends CI_Model {



    function __construct() {

        parent::__construct();

    }



    function createCaptcha($cap) {

        $data = array(

            'captcha_time' => $cap['time'],

            'ip_address' => $this->input->ip_address(),

            'word' => $cap['word']

        );



        $query = $this->db->insert_string('captcha', $data);

        $this->db->query($query);

        return $captchaId = $this->db->insert_id();

    }





    function checkCaptchaAccuracy($captcha, $captchaId) {

        $this->db->from("captcha");

        $this->db->where('word', $captcha);

        $this->db->where('captcha_id', $captchaId);

        $this->db->where('ip_address', $this->input->ip_address());

        $availabilty = $this->db->get();

        return $numRows = $availabilty->num_rows();

    }

}


View


    





























 

               
         

                
        
            

                

                

            		            


                    echo $image;

?>

                		            
            
                Enter the word you see above

Javascript
function checkCaptcha(baseurl,captcha,captchaId){

    document.getElementById('captchaId').value = captchaId;

    httpObject = getHTTPObject();

    if (window.XMLHttpRequest)

    {// code for IE7+, Firefox, Chrome, Opera, Safari

        var xmlhttp=new XMLHttpRequest();

    }

    else

    {// code for IE6, IE5

        xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");

    }

    xmlhttp.onreadystatechange=function()

    {

        if (xmlhttp.readyState==4 && xmlhttp.status==200)

        {

if(xmlhttp.responseText==1){

document.getElementById('message').innerHTML = 'Entered Captcha is Correct';

}

            

        }

    }

    xmlhttp.open("POST", baseurl+"/user/checkCaptcha/"+captcha+'/'+captchaId, true);

    xmlhttp.send(null);

}