Add captcha validation to my custom form for Frontend posting

Question

i have implemented the frontend form, which enables UNREGISTERED users to post on my site.

Everything in working perfectly, the only problem I have is with the implementation of the captcha.

All of the captcha solutions I found needs to put some outer file in the form action. But my form has this syntax:

<form action=""> 

I do not know what to do? If I put the file in the action field, I cannot add the post anymore. How would I put the verification code for the captcha in the same file as the form is? Or any better solution?

EDIT: How can I modify the form, that it would do the same thing (add post) as it does it now, but that I could include some file in the form action:

<form action="some.php">

Answer 1

Try Really Simple Captcha WodPress plugin. Here is a "how to" for implementing Really Simple Captcha for custom plugins: http://www.lost-in-code.com/platforms/wordpress/wordpress-plugins/wordpress-using-really-simple-captcha/

Answer 2

Use jQuery and first send the form content, here the captcha, to your file where the captcha is checked. Then send the form data to your posting routine.

$( '#frontend-post-form-submit' ).click(
  function(event) {
    var data = { ... insert the captcha from the form here ... };
    $.post(
      'some_file.php',
      data,
      function( result ) {
        // stop if the captcha isn't correct
        if ( false === result.result ) {
          event.preventDefault();
        }

        return result.result;
       }
     );
  }
);

If your submit button have the id frontend-post-form-submit and the captcha isn't correct, the jQuery will stop sending the form (event.preventDefault). Else the form will be submitted normally.