[ 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 (as of 2.2.2)
* 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 $courses = array(
            '27',
            '100'
        );

        private $admins = array(
            '[email protected]',
            '[email protected]'
        );

        private $survey_url = 'http://www.example.com';

        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() {
            
            $this->init();

        }

        private function init(){

            add_filter( 'the_content',  array( $this, 'wpmudev_coursepress_completion_email' ) );

        }

        public function wpmudev_coursepress_completion_email( $content ){

            global $wp, $post;

            // Check if is the course we need
            if( ! in_array( $post->ID, $this->courses ) ){
                return $content;
            }

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

            // Upon completion, do the following
            if ( ! empty( $wp->query_vars['course_completion'] ) ) {
        
                $headers            = array();
                $admins             = array();
                $survey_url         = $this->survey_url;
                $course_title 		= $post->post_title;
                $student 			= get_user_by( 'ID', get_current_user_id() );
                $send_to            = $student->data->user_email;
                $email_subject 		= "Thank you for completing \"{$course_title}\"";
                $email_content 		= '';
                $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' )
                                    );

                // Enable HTML Support
                add_filter( 'wp_mail_content_type', function(){ return "text/html"; } );
        
                // Email body
                $email_content = "Dear {$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.";

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

                // Check for admins, notify them and add them as Cc
                if ( ! empty( $this->admins ) ){
                    foreach( $this->admins as $email ){
                        if( filter_var( $email, FILTER_VALIDATE_EMAIL ) ){
                            $headers[] = "Cc: {$email}";
                            wp_mail( $email, $email_subject, nl2br( $email_content ) );
                            // Add a delay if you experience sending issues
                            // sleep( 5 );
                        }
                    }
                }

                // Send notification to student, adding admins as Cc
                if( wp_mail( $send_to, $email_subject, nl2br( $email_content ), $headers ) ){
                    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 );
    }

}