reCaptcha-Controller-1.php

<?php
class Test extends Controller
{
    // store your private/public key
    private $_recaptcha_private_key = 'YOUR PRIVATE KEY GOES HERE';
    private $_recaptcha_public_key = 'YOUR PUBLIC KEY GOES HERE';
    
    function __construct()
    {
        parent::__construct();
        $this->load->helper('recaptcha');
    }

    function someAction()
    {
        $this->load->library('form_validation');
        // set validation rule for the recaptcha response
        $this->form_validation->set_rules('recaptcha_response_field', 'reCaptcha', 'required|callback_recaptcha_check');
        if ($this->form_validation->run() === FALSE)
        {
            // store the recaptcha html code for the view
            $data['recaptcha'] = recaptcha_get_html($this->_recaptcha_public_key);
            // pass the data to the view
            $this->load->view('someView', $data);
        }
        else
        {
            // party
        }
    }
    function recaptcha_check($response)
    {
        // check to see if the recaptcha is correct
        $resp = recaptcha_check_answer (
                                        $this->_recaptcha_private_key,
                                        $this->input->ip_address(),
                                        $this->input->post('recaptcha_challenge_field'),
                                        $this->input->post('recaptcha_response_field'));
         if(!$resp->is_valid)
         {
             //reCaptcha is wrong
             $this->form_validation->set_message('recaptcha_check', 'reCaptcha was wrong.');
             return FALSE;
         }
         return TRUE;
    }        
}