WordPress Multisite Domain Mapping & Visual Composer

class.mapping-composer.php

<?php
if ( ! class_exists( 'MultsiteComposer' ) ) {
	class MultsiteComposer {
		public static function init() {
			if ( isset( $_GET['vc_action'] ) || isset( $_GET['vc_editable'] ) ) {
				if ( defined( 'DOMAIN_MAPPING' ) ) {
					remove_filter( 'plugins_url', 'domain_mapping_plugins_uri', 1 );
					remove_filter( 'theme_root_uri', 'domain_mapping_themes_uri', 1 );
					remove_filter( 'pre_option_siteurl', 'domain_mapping_siteurl' );
					remove_filter( 'pre_option_home', 'domain_mapping_siteurl' );
					remove_filter( 'the_content', 'domain_mapping_post_content' );
					remove_action( 'wp_head', 'remote_login_js_loader' );
					remove_action( 'login_head', 'redirect_login_to_orig' );
					remove_action( 'wp_logout', 'remote_logout_loader', 9999 );

					remove_filter( 'stylesheet_uri', 'domain_mapping_post_content' );
					remove_filter( 'stylesheet_directory', 'domain_mapping_post_content' );
					remove_filter( 'stylesheet_directory_uri', 'domain_mapping_post_content' );
					remove_filter( 'template_directory', 'domain_mapping_post_content' );
					remove_filter( 'template_directory_uri', 'domain_mapping_post_content' );
					remove_filter( 'plugins_url', 'domain_mapping_post_content' );
				} else {
					remove_filter( 'admin_url', 'domain_mapping_adminurl', 10 );
				}
				remove_action( 'admin_init', 'dm_redirect_admin' );

				if ( isset( $_GET['dm'] ) ) {
					remove_action( 'template_redirect', 'remote_login_js' );
				}

				remove_action( 'template_redirect', 'redirect_to_mapped_domain' );

				remove_action( 'delete_blog', 'delete_blog_domain_mapping', 1 );


				remove_filter( 'wpmu_blogs_columns', 'ra_domain_mapping_columns' );

				remove_action( 'manage_blogs_custom_column', 'ra_domain_mapping_field', 1 );
				remove_action( 'manage_sites_custom_column', 'ra_domain_mapping_field', 1 );
			} else {
				if ( ! is_admin() ) {
					add_action( 'init', array( __CLASS__, 'init_buffer' ), 100 );
				}
			}

			add_filter( 'vc_get_inline_url', array( __CLASS__, 'vc_admin_url_filter' ) );
		}

		public static function vc_admin_url_filter( $url ) {
			return str_replace( get_option( 'siteurl' ), get_original_url( 'siteurl' ), $url );
		}

		public static function init_buffer() {
			ob_start( array( __CLASS__, 'buffer_callback' ) );
		}

		public static function buffer_callback( $buffer ) {
			//Some unmapped URLs appear, leading to missing fonts and other things. Lets replace them
			$urls['ori'] = get_original_url( 'siteurl' ) . '/wp-content/';
			$urls['mapped'] = get_option( 'siteurl' ) . '/wp-content/';
			$buffer = str_replace( $urls['ori'], $urls['mapped'], $buffer );

			$urls = str_replace( array( 'http://', 'https://' ), '//', $urls );
			$buffer = str_replace( $urls['ori'], $urls['mapped'], $buffer );

			return $buffer;
		}
	}

	MultsiteComposer::init();
}

Updated with some tweaks

Using a filter for editing the VC Edit URLs instead of a regex.

What does this do exactly?