How to use comment_notification_headers filter in WordPress

comment_notification_headers filter

Filters the comment notification email headers.

To use the comment_notification_headers filter, first, you have to register it using add_filter. You can write this code into the functions.php of your activated theme or in a custom WordPress Plugin.

We at WePlugins always prefer to create a custom WordPress Plugin while using hooks so nothing breaks when you update your WordPress Theme in the future.

In the below live example, we have defined a function weplugins_modify_comment_notification_headers_defaults which takes 2 parameters and we registered using add_filter. The first parameter comment_notification_headers is the name of the hook, The second parameter weplugins_modify_comment_notification_headers_defaults is the name of the function which needs to be called, the third parameter is the priority of calling the hook if the same hook is used multiple times and the last parameter is the number of arguments (if any) to be passed in the registered function.

Sometimes, you have to remove a registered hook so you can use remove_filter to remove the comment_notification_headers filter.

Parameters

Below are the 2 parameters required to use this hook.

• $message_headers: (string) Headers for the comment notification email.
• $comment_id: (string) Comment ID as a numeric string.

Live Example 1: Modifying Comment Notification Headers

Below is an example of how you can use this hook to modify the comment notification headers.

        function weplugins_modify_comment_notification_headers_defaults($message_headers, $comment_id) { 
            // Update the $message_headers variable according to your website requirements and return this variable.
            // You can modify the $message_headers variable conditionally too if you want.
            return $message_headers; 
        }
        // add the filter
        add_filter("comment_notification_headers", "weplugins_modify_comment_notification_headers_defaults", 10, 2);
    

Live Example 2: Removing a Hook Callback

To remove a hook callback, use the example below.

        remove_filter("comment_notification_headers", "weplugins_modify_comment_notification_headers_defaults", 10, 2);
    

Please make sure to provide the same callback function name, priority, and number of arguments while removing the hook callback.

Live Example 3: Conditional Modification

Here is an example of how you can conditionally modify the comment notification headers.

        function weplugins_conditional_modify_comment_notification_headers($message_headers, $comment_id) {
            if ($comment_id == 123) {
                $message_headers .= "CC: admin@example.com";
            }
            return $message_headers;
        }
        // add the filter
        add_filter("comment_notification_headers", "weplugins_conditional_modify_comment_notification_headers", 10, 2);
    

Contact Us

If you need customization or have any trouble using this hook, please Contact Us, and we’d be happy to assist you.