- Copy ext.accessible-captcha.php into your system/extensions folder
- Copy lang.accessible-captcha.php into your system/language/english folder
Note: You will probably want to edit the lang.core.php file to change the error messages associated with either no captcha submitted or an incorrect one. The keys are 'captcha_required' and 'captcha_incorrect' on or about lines 98 and 101 respectively.
Go to Utilities » Extensions and make sure that they are enabled then enable the Accessible Captcha extension. Click on Settings and add up to 8 question and answer pairs. It’s best to make sure that the answer is a single word but phrases are ok and you can customise them depending upon your website audience. So, for example you could have:
Question: What is missing: North, South, East?
Question: 2+2 is equal to?
Question: An … a day keeps the doctor away. What word is missing?
There are two additonal settings:
Answer Hinting, that places, after the questions, text showing the number of characters required to complete the answer after the question. The hint will be wrapped in a span with the class 'captcha-hints' like so:
What is missing: North, South, East? <span class="captcha-hints">4 character(s) required</span>
Wrap hints in ( and ), places braces around the hints like so:
What is missing: North, South, East? <span class="captcha-hints">(4 character(s) required)</span>
Use the captcha code as per the ExpressionEngine documentation but modify the explanatory text to describe the requirement to answer a question rather than type the text shown in an image.
The captcha will then be replaced by one of the questions you added in the extension settings. The answer is case insensitive.
Note that no other HTML (apart from that generated by the hints as above) is output so you can use whatever you wish to wrap and style the captcha question.