How to use comment_form_fields filter in WordPress

Working with WordPress hooks can be quite exciting, especially when you need to tweak the comment form fields. Today, we’re diving into the comment_form_fields filter. This filter is all about modifying the comment form fields, including the textarea. So, if you’ve ever wanted to customize the way comments are handled on your WordPress site, this is the hook for you!

To use the comment_form_fields filter, you’ll first need to register it using add_filter. You can pop this code into the functions.php file of your active theme or create a custom WordPress plugin. Personally, I always lean towards creating a custom plugin to keep things neat and avoid breaking changes during theme updates.

Example 1: Customizing Comment Fields

Here’s a way to redefine the default comment fields using the filter.

    $fields   =  array(
        'author' => '<p class="comment-form-author">' . '<label for="author">' . __( 'Name' ) . ( $req ? ' <span class="required">*</span>' : '' ) . '</label> ' .
                    '<input id="author" name="author" type="text" value="' . esc_attr( $commenter['comment_author'] ) . '" size="30" maxlength="245"' . $aria_req . $html_req . ' /></p>',
        'email'  => '<p class="comment-form-email"><label for="email">' . __( 'Email' ) . ( $req ? ' <span class="required">*</span>' : '' ) . '</label> ' .
                    '<input id="email" name="email" ' . ( $html5 ? 'type="email"' : 'type="text"' ) . ' value="' . esc_attr(  $commenter['comment_author_email'] ) . '" size="30" maxlength="100" aria-describedby="email-notes"' . $aria_req . $html_req  . ' /></p>',
        'url'    => '<p class="comment-form-url"><label for="url">' . __( 'Website' ) . '</label> ' .
                    '<input id="url" name="url" ' . ( $html5 ? 'type="url"' : 'type="text"' ) . ' value="' . esc_attr( $commenter['comment_author_url'] ) . '" size="30" maxlength="200" /></p>',
    );
    

Example 2: Modifying Comment Form Fields Defaults

Check out this function where you can adjust the comment fields to suit your needs.

    function weplugins_modify_comment_form_fields_defaults($comment_fields) { 
        // Update the $comment_fields variable according to your website requirements and return this variable. You can modify the $comment_fields variable conditionally too if you want.
        return $comment_fields; 
    }
    // add the filter
    add_filter( "comment_form_fields", "weplugins_modify_comment_form_fields_defaults", 10, 1 );
    

Example 3: Removing a Hook Callback

If you ever need to remove a registered hook, here’s how you can do it.

    remove_filter( "comment_form_fields", "weplugins_modify_comment_form_fields_defaults", 10, 1 );
    

Remember, when removing a hook callback, make sure to provide the same callback function name, priority, and number of arguments.