LearnPress REST API is a plugin which adds endpoints for LearnPress LMS to the WordPress REST API // EDIT: LearnPress released official version of a REST API for their core plugin. TheYou can read the docs in their website: https://docspress.thimpress.com/developer-learnpress/#sections-5 . LearnPress REST API has been introduced in version 4 of …

LearnPress REST API

<?php
   /*
	* Plugin Name: LearnPress to WP Rest API
	* Plugin URI: https://www.webapp.bg/wp-extensions/learnpress-rest-api
	* Description: A plugin to add endpoints for LearnPress to WP REST API
	* Version: 1.0
	* Author: Marin Stoyanov
	* Author URI: https://www.webapp.bg/
	* License: GPL2
	*/

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

// Add REST API support to an already registered post type.
add_filter( 'register_post_type_args', 'learnpress_post_type_args', 10, 2 );
 
function learnpress_post_type_args( $args, $post_type ) {
 
    if ( 'lp_course' === $post_type ) {
        $args['show_in_rest'] = true;
 
        // Optionally customize the rest_base or rest_controller_class
        $args['rest_base']             = 'courses';
        $args['rest_controller_class'] = 'WP_REST_Posts_Controller';
    }
 
    if ( 'lp_lesson' === $post_type ) {
        $args['show_in_rest'] = true;
 
        // Optionally customize the rest_base or rest_controller_class
        $args['rest_base']             = 'lessons';
        $args['rest_controller_class'] = 'WP_REST_Posts_Controller';
    }
 
    if ( 'lp_quiz' === $post_type ) {
        $args['show_in_rest'] = true;
 
        // Optionally customize the rest_base or rest_controller_class
        $args['rest_base']             = 'quizzes';
        $args['rest_controller_class'] = 'WP_REST_Posts_Controller';
    }
 
    if ( 'lp_question' === $post_type ) {
        $args['show_in_rest'] = true;
 
        // Optionally customize the rest_base or rest_controller_class
        $args['rest_base']             = 'questions';
        $args['rest_controller_class'] = 'WP_REST_Posts_Controller';
    }
 
    if ( 'lp_order' === $post_type ) {
        $args['show_in_rest'] = true;
 
        // Optionally customize the rest_base or rest_controller_class
        $args['rest_base']             = 'courses-orders';
        $args['rest_controller_class'] = 'WP_REST_Posts_Controller';
    }
 
    return $args;
}


// Add REST API support to an already registered taxonomy.
add_filter( 'register_taxonomy_args', 'learnpress_taxonomy_args', 10, 2 );
 
function learnpress_taxonomy_args( $args, $taxonomy_name ) {
 
    if ( 'course_category' === $taxonomy_name ) {
        $args['show_in_rest'] = true;
 
        // Optionally customize the rest_base or rest_controller_class
        $args['rest_base']             = 'course-categories';
        $args['rest_controller_class'] = 'WP_REST_Terms_Controller';
    }
 
    return $args;
}

// Add REST API support to custom fields for custom post types
add_action( 'rest_api_init', 'learnpress_register_custom_fields' );

function learnpress_register_custom_fields() {

    // Course custom fields

    register_rest_field( 'lp_course', '_lp_duration', array(
        'get_callback' => 'show_fields'
    ) );

    register_rest_field( 'lp_course', '_lp_max_students', array(
        'get_callback' => 'show_fields'
    ) );

    register_rest_field( 'lp_course', '_lp_students', array(
        'get_callback' => 'show_fields'
    ) );

    register_rest_field( 'lp_course', '_lp_retake_count', array(
        'get_callback' => 'show_fields'
    ) );

    register_rest_field( 'lp_course', '_lp_featured', array(
        'get_callback' => 'show_fields'
    ) );

    register_rest_field( 'lp_course', '_lp_submission', array(
        'get_callback' => 'show_fields'
    ) );

    register_rest_field( 'lp_course', '_lp_course_result', array(
        'get_callback' => 'show_fields'
    ) );

    register_rest_field( 'lp_course', '_lp_passing_condition', array(
        'get_callback' => 'show_fields'
    ) );

    register_rest_field( 'lp_course', '_lp_price', array(
        'get_callback' => 'show_fields'
    ) );

    register_rest_field( 'lp_course', '_lp_sale_price', array(
        'get_callback' => 'show_fields'
    ) );

    register_rest_field( 'lp_course', '_lp_sale_start', array(
        'get_callback' => 'show_fields'
    ) );

    register_rest_field( 'lp_course', '_lp_sale_end', array(
        'get_callback' => 'show_fields'
    ) );

    register_rest_field( 'lp_course', '_lp_required_enroll', array(
        'get_callback' => 'show_fields'
    ) );

    register_rest_field( 'lp_course', '_lp_curriculum', array(
        'get_callback' => '_lp_curriculum',
        'permission_callback' => '__return_true'
    ) );

    // Lesson custom fields

    register_rest_field( 'lp_lesson', '_lp_duration', array(
        'get_callback' => 'show_fields'
    ) );

    register_rest_field( 'lp_lesson', '_lp_preview', array(
        'get_callback' => 'show_fields'
    ) );

    // register_rest_field( 'lp_lesson', '_lp_curriculum', array(
    //     'get_callback' => 'show_fields'
    // ) );
}

function show_fields($object, $field_name, $request) {
    return get_post_meta( $object['id'], $field_name, true );
}

function _lp_curriculum( $object, $field_name, $request ) {
    global $course;

    $curriculum = $course->get_curriculum();

    $array = $array_item = [];

    foreach ( $curriculum as $section_key => $section ) {

        $section_title = $section->get_title();

        $items = $section->get_items();

        if ( ! empty( $items ) ) {
            foreach ( $items as $items_key => $item ) {
                $type = $item->get_item_type(); 
                $link = $item->get_permalink();
                $title = $item->get_title( 'display' );

                $array_item[] = array(
                    'id' => $items_key,
                    'type' => $type,
                    'link' => $link,
                    'title' => $title
                );
            } 
        }

        $array[] = array(
            'id'    => $section_key,
            'title' => $section_title,
            'items' => $array_item
        );
    }

    return $array;
}