Create custom joomla captcha

Question

I've been assigned to create a captcha verification for a custom component in joomla, but I'm stuck at how to do it properly.
I'm aware of the fact that there are many captcha plugins like recaptcha available but I am required to use a custom captcha created by the company.
It saves the image text in a session and creates the image in a component so calling index.php?option=com_captcha directly in the browser will output a captcha image.

The problem is that I'm completely new to joomla and can't seem to find a proper way to create code that could be reused through out the system. I tried to do this by creating a module that would call the captcha component, then do the logic and check if captcha was correct.
The problem I faced with doing this was the fact that I couldn't find a way to pass variables to my module, thus I couldn't pass the session variable that's required by captcha component.

I've looked at plugins but I'm not sure that you can call a plugin directly from a component.

I'm currently stumped and got no ideas which direction to go to and what to search for. Any help will be appreciated, thanks.

Answer 1

You don't mention your Joomla! version but if it's 1.6+ why not use a captcha plugin?

Then any third party extension can use it automatically if you set it as the sites default captcha mechanism.

Plugins are also a lot easier to write than a component... captcha plugins only have a few required methods — onInit($id), onDisplay($name, $id, $class) and onCheckAnswer($code)