Validation - optional fields + callbacks + other rules

[eluser]coolfactor[/eluser]
The fix is simply to remove the check for a callback function. Here's the same code as above, but with the callback removed:

Code:

// Is the field required?  If not, if the field is blank  we'll move on to the next test
if ( ! in_array('required', $ex, TRUE))
{
    if ( ! isset($_POST[$field]) OR $_POST[$field] == '')
    {
        continue;
    }
}

Callbacks are then treated the same as other functions. If the field is optional, they are only called if the field exists in $_POST and has a non-empty value.