Using codeigniter to execute code from another file - codeigniter

Question

I am new to CodeIgniter and I am used to the old school php scripting so I'll need some help with this:
I want to include a Captcha system in one of my forms.
According to its documentation, to generate an image, you need to do it like this:
<img id="captcha" src="/securimage/securimage_show" alt="CAPTCHA Image" />
I downloaded the files, but where do I put them? And how do I use Codeigniter to call the securimage_show.php file? And output its contents into the src attribute of the image?

Answer 1

When adding Captcha in Fuel (a codeigniter based cms), I've put the php file that generates the Captcha image in the folder where you put images, then link to it the same way you link to an image:
<?php echo img(array('src'=>'image_show.php', 'alt'=> 'CAPTCHA Image')); ?>
Perhaps not the nicest solution, but it works.
Alternatively, just use a Captcha plugin written specifically for codeigniter, such as the NuCaptcha CodeIgniter plugin, http://docs.nucaptcha.com/plugins/codeigniter.

Answer 2

Codeigiter have a captcha helper.
First, you want to create a folder where you will be able to store your captcha images and give this folder permissions to perform read/write operations. In this case, I've created captcha folder in root of my codeigniter instance.
Then, we want to load captcha helper:
$this->load->helper('captcha');
Let's initiate instance of captcha with our settings (you can do it either in Controller or View with your form):
$rand_string = strtoupper(random_string('nozero', 4));
$settings = array(
'word' => $rand_string,
'img_path' => './captcha/',
'img_url' => base_url() .'captcha/',
'img_width' => '250',
'img_height' => 35,
'expiration' => 7200
);
$cap = create_captcha($settings);
$this->session->set_userdata('captchaWord',$cap['word']);
Please note, that I'm keeping generated captcha word in my session whenever I create it (for instance on page refresh). This way I can compare original captcha word with input from my form. Then, I will display generated captcha image with input field somewhere in my form (View):
<form id="my_form">
<input type="text" name="captcha" value=""/>
<?= $cap['image']; ?>
</form>
Now, all I have to do, is to compare input received from my_form with actual captcha value (in my controller, where I handle form submission):
$userCaptcha = $this->input->post('captcha');
$actual_word = $this->session->userdata('captchaWord');
if( strcmp(strtoupper($userCaptcha),strtoupper($actual_word)) == 0 ) {
// input and captcha are the same
}