LearnDash Post Arguments

LearnDash Post Arguments

// Adding Custom Configuration field in LearnDash Topics
add_filter( 'learndash_post_args', 'add_topic_option' );
function add_topic_option( $post_args ) {

	global $pagenow;
	$topic_id = $_GET['post'];

	// If in Topic Edit Screen
	if ( $pagenow == 'post.php' && get_post_type( $topic_id ) == 'sfwd-topic' ) {
		
		$lesson_id = get_post_meta( $topic_id, 'lesson_id', true );

		if( $lesson_id ) {
	    	$courses = get_posts( array(
				'num' => '-1', 
				'post_type' => 'sfwd-topic', 
				'post_status' => 'publish',
				'post__not_in' => array( $topic_id ), 
				'order' => 'DESC', 
				'orderby' => 'ID',
				'fields' => 'ids',
				'meta_query' => array(
				       array(
				           'key' => 'lesson_id',
				           'value' => $lesson_id ,
				           'compare' => '=',
				       )
				   )
			));
	    }	    
		
	} // End if Topic Edit Screen

	// If the courses have more than 1 topics then list them excluding the current topic.
	if( is_array( $courses ) ) {
		$course_array[0] = 'Please Select';

		foreach( $courses as $course_id ) {
			$course_array[$course_id] = get_the_title( $course_id ); 
		}
	} else {
		$course_array = array();
	}
	
	// New Topic field listing other topics of the same lesson.
	$vcoursefield = array(
		'visible_after_completed' => array(
		'name' => __( 'Visible After Completed', 'learndash' ), 
		'type' => 'select', // multiselect 
		'initial_options' => $course_array,
		'help_text' => __( 'Select Prerequisite Topics From Same Lesson', 'learndash' ), 
		'default' => 0,
		'show_in_rest' => true,
	));
	
	// Pass the new field in the topic fields array.
	$post_args['sfwd-topic']['fields'] = array_merge( $vcoursefield, $post_args['sfwd-topic']['fields'] );
	
	return $post_args;
}