Question

I want Drupal comments to work like every other blog’s comments. Who are writing their homepage URL can write “www.example.com,” or “http://www.example.com,” and they both work. Right now, Drupal throws an error if the URL doesn’t contain “http://.”

Answer 1

You could override the comment_validate hook in /modules/comment/comment.module and modify the validation code to insert the http:// bit into the URL if it’s not already there. The changed code would look something like:

if ($edit['homepage']) {
    if (!strpos($edit['homepage'], "http://")) {
        $edit['homepage'] = "http://" . $edit['homepage'];
    }
    if (!valid_url($edit['homepage'], TRUE)) {
        form_set_error('homepage', t('The URL of your homepage is not valid. Remember that it must be fully qualified, i.e. of the form <code>http://example.com/directory</code>.'));
    }
}

You would also need to override the comment_form_validate hook:

function comment_form_validate($form, &$form_state) {
  global $user;
  if ($user->uid === 0) {
    foreach (array('name', 'homepage', 'mail') as $field) {
      // Set cookie for 365 days.
      if (isset($form_state['values'][$field])) {
        setcookie('comment_info_'. $field, $form_state['values'][$field], time() + 31536000, '/');
      }
    }
  }
  $form_state['values'] = comment_validate($form_state['values']);
}