How to use comment_notification_subject filter in WordPress

comment_notification_subject filter

Filters the comment notification email subject.

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

At WePlugins, we 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 modify_comment_notification_subject_defaults which takes 2 parameters, and we registered it using add_filter. The first parameter comment_notification_subject is the name of the hook, the second parameter modify_comment_notification_subject_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 comment_notification_subject filter.

Parameters

Below are the 2 parameters required to use this hook.

• $subject: (string) The comment notification email subject.
• $comment_id: (string) Comment ID as a numeric string.

Example 1: Modify Comment Notification Subject

Below is an example of how you can use this hook.

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

Example 2: Remove Comment Notification Subject Filter

To remove a hook callback, use the example below.

    remove_filter("comment_notification_subject", "weplugins_modify_comment_notification_subject_defaults", 10, 2);
    

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

Example 3: Conditional Subject Modification

Here is how you can conditionally change the subject based on the comment ID.

    function weplugins_conditional_comment_subject_change($subject, $comment_id) {
        if ($comment_id == '123') {
            $subject = "Special Comment Notification!";
        }
        return $subject;
    }
    add_filter("comment_notification_subject", "weplugins_conditional_comment_subject_change", 10, 2);
    

Contact Us

If you’re having any trouble using this hook or need customization, please contact us and we’d be happy to assist you.