Allow comments for Lessons.

pmpro-courses-enable-comment-support-for-lessons.php

<?php
/**
 * Enable comment support for the pmpro_lesson custom post type.
 *
 * Allowing users to comment on lessons may be set with the "Allow comments"
 * checkbox option in the "Discussion" metabox on the lesson edit screen.
 *
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */

function my_pmpro_courses_enable_comment_support_for_lessons( $args, $post_type ) {
	if ( ! function_exists( 'pmpro_courses_is_module_active' ) || ! pmpro_courses_is_module_active( 'default' ) ) {
		return $args;
	}
	// if post type does not support comments, add support for comments.
	if ( 'pmpro_lesson' === $post_type && ! post_type_supports( $post_type, 'comments' ) ) {
		$args['supports'][] = 'comments';
	}

	return $args;
}
add_filter( 'register_post_type_args', 'my_pmpro_courses_enable_comment_support_for_lessons', 10, 2 );

// Enable allow comments by default for new lessons.
function my_pmpro_courses_enable_allow_comments_for_lessons( $data, $postarr ) {
	if ( ! function_exists( 'pmpro_courses_is_module_active' ) || ! pmpro_courses_is_module_active( 'default' ) ) {
		return $data;
	}
	if ( 'pmpro_lesson' === $data['post_type'] && post_type_supports( $data['post_type'], 'comments' ) ) {
		$data['comment_status'] = 'open';
	}

	return $data;
}
add_filter( 'wp_insert_post_data', 'my_pmpro_courses_enable_allow_comments_for_lessons', 10, 2 );