[ CoursePress 2 ] - Email Notifications on Completion. Sends an email notification to the Student upon Course Completion

wpmudev-coursepress-completion-email.php

<?php
/**
* Plugin Name: [ CoursePress 2 ] - Email Notifications on Completion
* Plugin URI: https://premium.wpmudev.org/
* Description: Sends an email notification to the Student upon Course Completion
* Author: Alessandro Kaounas @ WPMUDEV
* Author URI: https://premium.wpmudev.org/
* License: GPLv2 or later
*/

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

if ( ! class_exists( 'WPMUDEV_CoursePress_Completion_Email' ) ) {
    
    class WPMUDEV_CoursePress_Completion_Email {

        private static $_instance = null;

        public static function get_instance() {

            if( is_null( self::$_instance ) ){
                self::$_instance = new WPMUDEV_CoursePress_Completion_Email();
            }
            return self::$_instance;
            
        }

        private function __construct() {
            
            add_filter( 'the_content', function( $content ){

                global $wp, $post;

                // Check if user has already got an email
                if( metadata_exists( 'post', $post->ID, 'course_completed_email_' . get_current_user_id() ) ){
                    return $content;
                }

                if ( ! empty( $wp->query_vars['course_completion'] ) ) {
            
                    $survey_url         = 'http://www.example.com';
                    $send_to 			= array();
                    $email_subject 		= 'A student has completed a course!';
                    $email_content 		= '';
                    $course_title 		= $post->post_title;
                    $student 			= get_user_by( 'ID', get_current_user_id() );
                    $instructors 		= (array) CoursePress_Data_Course::get_setting( $post->ID, 'instructors', array() );
                    $assessment_link 	= add_query_arg(
                                            array(
                                                'post_type' => 'course',
                                                'page' => 'coursepress_assessments',
                                                'view' => 'profile',
                                                'course_id' => $post->ID,
                                                'student_id' => $student->data->ID,
                                            ),
                                            admin_url( 'edit.php' )
                                        );
            
                    $send_to[] = '[email protected]';
		    $send_to[] = '[email protected]';

                    // Enable HTML Support
                    add_filter( 'wp_mail_content_type', function(){ return "text/html"; } );
            
                    $email_content = "Dear {$student->data->display_name},\n
                    Congratulations on successful completion of {$course_title}!\n
                    Your certificate of completion is being processed and will be delivered to you via email in the next 1-2 business days.\n
                    In the meantime, if you could provide us some feedback on your experience, that would be very helpful in the development of our e-training program.\n
                    Click the link the below and complete this brief, 2-minute survey to receive 10% off any future Geophysical Insights course purchase.";

                    if($survey_url){
                        $email_content .= "\n<a href='{$survey_url}'>{$survey_url}</a>";
                    }

                    if( wp_mail( $send_to, $email_subject, nl2br( $email_content ) ) ){
                        add_post_meta( $post->ID, 'course_completed_email_' . get_current_user_id(), $student->data->user_email );
                    }

                }
            
                return $content;

            } );

        }

	}
	
    if ( ! function_exists( 'WPMUDEV_CoursePress_Completion_Email' ) ) {
        
        function WPMUDEV_CoursePress_Completion_Email() {
            return WPMUDEV_CoursePress_Completion_Email::get_instance();
        };

        add_action( 'plugins_loaded', 'WPMUDEV_CoursePress_Completion_Email', 99 );
    }

}