How to use comment_feed_groupby filter in WordPress

comment_feed_groupby filter

Filters the GROUP BY clause of the comments feed query before sending.

To use comment_feed_groupby 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.

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 modify_comment_feed_groupby_defaults which takes 2 parameters and we registered using add_filter. The first parameter comment_feed_groupby is the name of the hook, The second parameter modify_comment_feed_groupby_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_feed_groupby filter.

Parameters

Below are the 2 parameters required to use this hook.

• $cgroupby: (string) The GROUP BY clause of the query.
• $query: (WP_Query) The WP_Query instance (passed by reference).

Live Example 1

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

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

Live Example 2

To remove a hook callback, use the example below.

    remove_filter("comment_feed_groupby", "weplugins_modify_comment_feed_groupby_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

Another example to customize the GROUP BY clause.

    function weplugins_custom_comment_feed_groupby($cgroupby, $query) {
        if (is_feed() && !is_admin()) {
            // Custom GROUP BY logic
            $cgroupby = 'wp_comments.comment_post_ID';
        }
        return $cgroupby;
    }
    // add the filter
    add_filter("comment_feed_groupby", "weplugins_custom_comment_feed_groupby", 10, 2);