WP MU Plugin: Polylang multidomain Elementor assets URL

polylang-elementor-assets-url.php

<?php
/**
 * MU plugin. Need to be used together with regular plugin.
 *
 * Plugin Name: Polylang Elementor Cross Domain Assets URL
 * Description: Fixes cross origin domain issues with Elementor and Polylang
 * Version: 1.0
 * Author: Jory Hogeveen
 * Author URI: http://www.keraweb.nl/
 */

add_filter( 'plugins_url', function ( $url ) {
	if ( false === strpos( $url, 'elementor' ) ) {
		return $url;
	}

	$pll_options = get_option( 'polylang' );
	if ( ! isset( $pll_options['domains'] ) ) {
	// Not a multidomain configuration.
		return $url;
	}

	$domains = $pll_options['domains'];
	$host    = $_SERVER['HTTP_HOST'];

	foreach ( $domains as $domain ) {
		if ( false !== strpos( $domain, $host ) ) {
			$url_parts = parse_url( $url );
			$url = str_replace( $url_parts['host'], $host, $url );
			break;
		}
	}
	return $url;
} );

polylang-elementor-assets.php

<?php
/*
 * Non-MU plugin. Need to be used together with MU plugin.
 *
 * Based on code from @nicmare: https://github.com/polylang/polylang/issues/590#issuecomment-721782112
 *
 * Plugin Name: Polylang Elementor Cross Domain Assets
 * Description: Fixes cross origin domain issues with Elementor and Polylang
 * Version: 1.0
 * Author: Jory Hogeveen
 * Author URI: http://www.keraweb.nl/
*/

Polylang_Elementor_Assets::get_instance();

class Polylang_Elementor_Assets
{
	private static $_instance = null;

	protected $current_domain = '';
	protected $default_domain = '';
	protected $current_language = '';
	protected $default_language = '';
	protected $all_domains = array();

	protected function __construct() {
		add_action( 'init', array( $this, 'init' ) );
	}

	public function init() {
		if ( ! function_exists( 'pll_current_language' ) ) {
			return;
		}

		$return = OBJECT;
		$current_language = pll_current_language( $return );
		$default_language = pll_default_language( $return );

		if ( ! $current_language || ! $default_language ) {
			return;
		}

		$is_preview = isset( $_GET['elementor_preview'] );
		$is_editor  = ( isset( $_GET['action'] ) && 'elementor' === $_GET['action'] );

		if ( ! $is_editor && ! $is_preview ) {
			return;
		}
		$languages = pll_the_languages( array( 'raw' => true ) );

		foreach ( $languages as $language ) {
			$this->all_domains[] = $language['url'];
			if ( false !== stripos( $language['url'], $_SERVER['SERVER_NAME'] ) ) {
				$current_language = PLL()->model->get_language( $language['slug'] );
				break;
			}
		}

		$this->current_domain = $current_language->home_url;
		$this->default_domain = $default_language->home_url;
		$this->current_language = $current_language->slug;
		$this->default_language = $default_language->slug;

		add_filter( 'script_loader_src', array( $this, 'translate_url' ) );
		add_filter( 'style_loader_src', array( $this, 'translate_url' ) );

		add_filter( 'allowed_http_origins', array( $this, 'add_allowed_origins' ) );

		add_filter( 'wp_get_attachment_image_attributes', array( $this, 'check_for_src' ),10,2 );
		add_filter( 'admin_url', array( $this, 'modify_adminy_url_for_ajax' ), 10, 3 );

		add_filter( 'post_row_actions', array( $this, 'elementor_links_fix' ), 12, 2 );
		add_filter( 'page_row_actions', array( $this, 'elementor_links_fix' ), 12, 2 );

		add_filter( 'elementor/editor/localize_settings', array( $this, 'translate_url_recursive' ) );
	}

	public function translate_url( $url ) {
		return str_replace( $this->default_domain, $this->current_domain, $url );
	}

	public function translate_url_recursive( $data ) {
		if ( is_string( $data ) ) {
			$data = $this->translate_url( $data );
		} elseif ( is_array( $data ) ) {
			$data = array_map( array( $this, 'translate_url_recursive' ), $data );
		}
		return $data;
	}

	public function add_allowed_origins( $origins ) {
		$origins[] = $this->current_domain;
		$origins = array_merge( $origins, $this->all_domains );
		return $origins;
	}

	public function modify_adminy_url_for_ajax( $url, $path, $blog_id ) {
		if ( 'admin-ajax.php' == $path ) {
			return $this->translate_url( $url );
		}
		return $url;
	}

	public function check_for_src($attr, $attachment) {
		$attr['src'] = $this->translate_url( $attr['src'] );
		$attr['srcset'] = $this->translate_url( $attr['srcset'] );
		return $attr;
	}

	// change the edit and elementor-edit links in post table
	public function elementor_links_fix( $actions, $post ) {
		if(empty($actions['edit_with_elementor'])) return $actions;
		if(!function_exists("pll_get_post_language")) return $actions;

		if ( pll_get_post_language( $post->ID ) != pll_default_language() ) {
			$actions['edit'] = $this->translate_url( $actions['edit'] );
			$actions['edit_with_elementor'] = $this->translate_url( $actions['edit_with_elementor'] );
		}

		return $actions;
	}

	public static function get_instance() {
		if ( ! self::$_instance ) {
			self::$_instance = new self();
		}
		return self::$_instance;
	}
}

The solution works in 2023! Jory, thank you so much, you really helped out by posting this simple but ingenious code.
The only thing was that I had to do a little bit of processing for some of the templates:

`
public function check_for_src($attr, $attachment) {
if ( isset( $attr['src'] ) ) {
$attr['src'] = $this->translate_url( $attr['src'] );
}

if ( isset( $attr['srcset'] ) ) {
    $srcset_parts = explode( ', ', $attr['srcset'] );
    $srcset_parts = array_map( function( $src ) {
        $src_info = explode( ' ', $src );
        $src_info[0] = $this->translate_url( $src_info[0] );
        return implode( ' ', $src_info );
    }, $srcset_parts );
    $attr['srcset'] = implode( ', ', $srcset_parts );
}
return $attr;

}
`