After upgrading to Joomla 3.9.15, my site / extension / custom form captcha stopped working. I get "Please complete the CAPTCHA" or "invalid-input-response" or something like "Invalid Captcha". What happened?
Answer for Joomla Users
An update of the Captcha - ReCaptcha plugin changed the existing functionality and many of the extension developers need to update the way their extensions handled Captcha responses.
So, a first step is to be 100% sure that you are using the latest version available!
If you are sure about that, please contact the extension developer and include a link to this page. It may help them.
Answer for Extension Developers
The Captcha - ReCaptcha plugin changed the way they handled the onCheckAnswer event. A similar change happened back in 2016, where we had to change the way we included captcha plugins.
Your code may look something like this:
$captcha = JCaptcha::getInstance(JFactory::getConfig()->get('captcha'));
if (!$captcha->checkAnswer('my-recaptcha-id')) {
// handle captcha not answered
}
Up until now, the onCheckAnswer event completely ignored our input. Instead, it loaded the correct response for Google ReCaptcha by calling:
$input->get('g-recaptcha-response', '', 'string');
This changed on 25 Dec 2019. Now, our input is used to directly validate the captcha response. So, an easy way to bypass this is to do the following:
if (!$captcha->checkAnswer(null)) {
// handle captcha not answered
}
If you want your code to be 100% consistent, then assuming you have:
print JCaptcha::getInstance(JFactory::getConfig()->get('captcha'))->display('my_field_id', 'my_field_id', 'g-recaptcha');
You would write:
$input = JFactory::getApplication()->input;
if (!$captcha->checkAnswer($input->get('my_field_id', null, 'string')) {
// handle captcha not answered
}
BUT! You have to remember that the ReCaptcha plugin ignores our Captcha ID input anyway, so the above currently serves as a nice wrapper around null anyway.
