Disable postMessage for built-in WordPress menus in Customizer

customizer-disable-postmessage-for-menus.php

<?php
/**
 * Customizer customizations: some highly customized implementations of menus might not work correctly
 * with the default postMessage transport in the WordPress Customizer. This code will revert menus
 * to use the basic 'refresh' transport, which is slower but can be more reliable.
 *
 * @param \WP_Customize_Manager $wp_customize Core object for manipulating the Customizer.
 */
function my_customize_register( WP_Customize_Manager $wp_customize ) {

	// Use standard refresh for menus
	// Loop through menu locations
	$menu_locations = get_registered_nav_menus();
	foreach ( $menu_locations as $location => $description ) {
		$setting_id = "nav_menu_locations[{$location}]";

		$setting = $wp_customize->get_setting( $setting_id );
		if ( $setting ) {
			$setting->transport = 'refresh';
		}
	}

	// Loop through individual menus.
	$menus = wp_get_nav_menus();
	foreach ( $menus as $menu ) {
		$menu_id = $menu->term_id;

		$nav_menu_setting_id = 'nav_menu[' . $menu_id . ']';
		$nav_menu_setting             = $wp_customize->get_setting( $nav_menu_setting_id );
		if ( $nav_menu_setting ) {
			$nav_menu_setting->transport = 'refresh';
		}

		// Loop through menu items within menus.
		$menu_items = (array) wp_get_nav_menu_items( $menu_id );
		foreach ( array_values( $menu_items ) as $i => $item ) {

			// Create a setting for each menu item (which doesn't actually manage data, currently).
			$menu_item_setting_id = 'nav_menu_item[' . $item->ID . ']';
			$menu_item_setting              = $wp_customize->get_setting( $menu_item_setting_id );
			if ( $menu_item_setting ) {
				$menu_item_setting->transport = 'refresh';
			}
		}
	}
}
add_action( 'customize_register', 'my_customize_register' );