[concrete5] MultilingualPageUrlResolver: Get localized page path from original page path

MultilingualPageUrlResolver.php

<?php
// application/src/Concrete/Url/MultilingualPageUrlResolver.php
namespace Application\Concrete\Url;

use Concrete\Core\Application\ApplicationAwareInterface;
use Concrete\Core\Application\ApplicationAwareTrait;
use Concrete\Core\Multilingual\Page\Section\Section;
use Concrete\Core\Page\Page;
use Concrete\Core\Url\Resolver\PageUrlResolver;
use Concrete\Core\Url\Resolver\UrlResolverInterface;

/**
 * Multilingual Page Url Resolver.
 *
 * \URL::to('/foo')
 *   -> 'http://www.example.com/foo' in default section
 *   -> 'http://www.example.com/ja/foo' in multilingual section
 */
class MultilingualPageUrlResolver implements UrlResolverInterface, ApplicationAwareInterface
{
    use ApplicationAwareTrait;

    /**
     * @var PageUrlResolver
     */
    protected $pageUrlResolver;

    /**
     * MultilingualPageUrlResolver constructor.
     *
     * @param PageUrlResolver $pageUrlResolver
     */
    public function __construct(PageUrlResolver $pageUrlResolver)
    {
        $this->pageUrlResolver = $pageUrlResolver;
    }

    /**
     * @param array $arguments
     * @param \League\URL\URLInterface|null $resolved
     *
     * @return \League\URL\URLInterface|null
     */
    public function resolve(array $arguments, $resolved = null)
    {
        if ($resolved) {
            // We don't need to do any post processing on urls.
            return $resolved;
        }

        if ($this->app->make('multilingual/detector')->isEnabled()) {
            if ($arguments) {
                $page = head($arguments);
            }

            if (isset($page) && (is_scalar($page) || (is_object($page) && method_exists($page, '__toString')))) {
                $path = (string) $page;
                if ($path == '/' || $path == '') {
                    $page = Page::getByID(Page::getHomePageID());
                } else {
                    $page = Page::getByPath($path);
                }
            }

            if (isset($page) && $page instanceof Page && !$page->isError() && $page->isActive()) {
                $c = Page::getCurrentPage();
                if (is_object($c) && !$c->isError()) {
                    $section = Section::getBySectionOfSite($c);
                }
                $pageSection = Section::getBySectionOfSite($page);
                if (isset($section) && is_object($section) && is_object($pageSection) && $section->getLocale() != $pageSection->getLocale()) {
                    $relatedID = $section->getTranslatedPageID($page);
                    if ($relatedID) {
                        $relatedPage = Page::getByID($relatedID);
                        if ($relatedPage && !$relatedPage->isError()) {
                            array_shift($arguments);
                            array_unshift($arguments, $relatedPage);

                            return $this->pageUrlResolver->resolve($arguments);
                        }
                    }
                }
            }
        }

        return null;
    }
}

How to add this resolver to your URL manager: add below code to application/bootstrap/app.php

use Concrete\Core\Url\Resolver\Manager\ResolverManagerInterface;
use Application\Concrete\Url\MultilingualPageUrlResolver;

$urlResolverManager = $this->app->make(ResolverManagerInterface::class);
$urlResolverManager->addResolver('application.multilingual', $this->app->make(MultilingualPageUrlResolver::class));

I had to do something similar (in functionality) one time. Does this work with more than one multilingual section?

@eskema Yes, it works.