Add Slack notifications for comments posted via the Epoch comment system

slack-epoch-comments.php

<?php
/*
Plugin Name: Slack Epoch Comments
Plugin URI: https://gist.github.com/macbookandrew/7f41ff7d4b28300f19bd
Description: Adds Slack notifications for comments posted via the Epoch comment system
Version: 1.1
Author: AndrewRMinion Design
Author URI: https://andrewrminion.com
*/

// add Epoch comment system to Slack notifications
function wp_slack_epoch( $events ) {
    $events['comment_post'] = array(
        'action' => 'comment_post',
        'description' => __( 'When a comment is posted via Epoch comment system', 'slack' ),
        'message' => function( $comment_id ) {
            $comment = get_comment( absint( $comment_id ) );
            $post_id = $comment->comment_post_ID;

            $notified_post_types = apply_filters( 'slack_event_wp_insert_comment_post_types', array(
                'post',
                'course_unit',
            ) );

            if ( ! in_array( get_post_type( $post_id ), $notified_post_types ) ) {
                return false;
            }

            $post_title = get_the_title( $post_id );
            $comment_status = wp_get_comment_status( $comment_id );

            // get user’s nicename if available
            $user = get_user_by( 'email', $comment->comment_author_email );
            if ( $user->data->display_name ) {
                $user_name = $user->data->display_name;
            } else {
                $user_name = $comment->comment_author;
            }

            // ignore spam
            if ( 'spam' === $comment_status ) {
                return false;
            }

            return sprintf(
                '<%4$s#comment-%1$s|New comment> by *%3$s* on *<%4$s|%5$s>* (_%2$s_)' . "\n" . '>%7$s' . "\n" . '<%6$sapprove|Approve it> | <%6$strash|Trash it> | <%6$sspam|Spam it> | <%4$s#comment-%1$s|See in context> | <%4$s?replytocom=%1$s#respond|Reply>',

                $comment_id,
                $comment_status,
                $user_name,
                get_permalink( $post_id ),
                $post_title,
                admin_url( "comment.php?c=$comment_id&action=" ),
                preg_replace( "/\n/", "\n>", get_comment_text( $comment_id ) )
            );
        }
    );

    return $events;
}
add_filter( 'slack_get_events', 'wp_slack_epoch' );

v1.0: initial plugin

v1.1: add support for user nice names, if available

v1.1.1: don’t show approve link if comment is already approved

v1.1.2: fix message if comment needs approval