replace_tag() receiving NULL for field data

Question

I am creating my own custom field type, and my replace_tag function is as follows:

function replace_tag($data, $params = array(), $tagdata = FALSE) {

    return $data; // NULL

}

The problem, as noted in the code, is that $data has no value. I have verified that the channel entry i'm display is correct, that field's data is properly stored in the database, and that if I manually set a value for $data inside the replace_tag() function, it prints to the template just fine.

Any suggestions as to what could be going wrong?

Thanks!

P.S. I started a thread here but never got responses. Trying this instead.

Answer 1

As pointed out by Rob Sanchez, my pre_process function wasn't returning field data.

If you have the pre_process function in your fieldtype class file but it doesn't return the $data parameter that it accepts, nothing will get passed to the replace_tag() function.

(Edit: clarity)