add plugin to notify central when there is pending posts

public_html/wp-content/plugins/notify-central-on-pending-posts.php

@@ -0,0 +1,55 @@
+<?php
+/**
+ * Plugin Name: Notify WordCamp Central on pending posts
+ * Plugin URI: http://wordcamp.org
+ * Description: Send email notification to WordCamp Central when post status becomes pending.
+ * Version: 1.0
+ *
+ * Heavily inspired from Pending Submission Notifications plugin by Razvan Horeanga.
+ */
+
+namespace Notify_Central_Pending_Posts;
+
+if ( ! defined( 'ABSPATH' ) ) {
+	die( 'Invalid request.' );
+}
+
+add_action( 'transition_post_status', __NAMESPACE__ . '\send_notification_email', 10, 3 );
+
+/**
+ * Send the notification email.
+ *
+ * @param string  $new_status New post status.
+ * @param string  $old_status Old post status.
+ * @param WP_Post $post       Post object.
+ */
+function send_notification_email( $new_status, $old_status, $post ) {
+	if ( 'pending' === $new_status && user_can( $post->post_author, 'edit_posts' ) ) {
+		// Prevent many emails from the same post.
+		$sent = get_post_meta( $post->ID, '_ncpp_sent', true );
+		if ( ! empty( $sent ) ) {
+			return;
+		}
+
+		$edit_link    = get_edit_post_link( $post->ID, '' );
+		$preview_link = get_permalink( $post->ID ) . '&preview=true';
+
+		$username           = get_userdata( $post->post_author );
+		$username_last_edit = get_the_modified_author();
+
+		$subject = __( 'New post on WordCamp Central pending review', 'wordcamporg' ) . ": {$post->post_title}";
+
+		$message  = __( 'Hello team! A new post on WordCamp Central is pending review.', 'wordcamporg' );
+		$message .= "\r\n\r\n";
+		$message .= __( 'Title' ) . ": {$post->post_title}\r\n";
+		$message .= __( 'Author' ) . ": {$username->user_login}\r\n";
+		$message .= "\r\n\r\n";
+		$message .= __( 'Edit' ) . ": {$edit_link}\r\n";
+		$message .= __( 'Preview' ) . ": {$preview_link}";
+
+		wp_mail( '[email protected]', $subject, $message );
+
+		// Save a pointer that notification has been sent.
+		update_post_meta( $post->ID, '_ncpp_sent', wp_date( 'Y-m-d H:i:s' ) );
+	}
+}