Add breadcrumbs to Courses with Classroom Mode enabled

mpcs-breadcrumbs-classroom.php

<?php

function add_course_breadcrumbs($content) {
  global $post;

  if(is_single()) {
    if(isset($post) && is_a($post, 'WP_Post') && in_array($post->post_type, memberpress\courses\models\Lesson::lesson_cpts())) {
      $current_lesson = new memberpress\courses\models\Lesson($post->ID);
      $current_section = $current_lesson->section();
      if($current_section !== false) {
        $current_course = $current_section->course();
        $options = \get_option('mpcs-options');
        \ob_start();
          require(\MeprView::file('/lessons/courses_breadcrumbs'));
        $breadcumbs = \ob_get_clean();

        $content = $breadcumbs . $content;
      }
    }
  }

  return $content;
}
add_filter('the_content', 'add_course_breadcrumbs');