Customise Laravel to support forcing the asset root at runtime

laravel-custom-routing-force-asset-path.php

<?php
namespace App\Services;

use Illuminate\Routing\UrlGenerator as BaseUrlGenerator;

class UrlGenerator extends BaseUrlGenerator
{
    /**
     * The original asset root so we can restore it
     */
    protected ?string $originalAssetRoot = null;

    /**
     * Force the asset root
     */
    public function forceAssetRootUrl(?string $root = null): void
    {
        if ($root) {
            $this->originalAssetRoot = $this->assetRoot;
            $this->assetRoot = $root;
        } else {
            $this->assetRoot = $this->originalAssetRoot;
            $this->originalAssetRoot = null;
        }
    }
}


// THEN IN App/Providers/AppServiceProvider.php
class AppServiceProvider
{
    /**
     * Override the URL generator to use our extension class which allows us to
     * change the base asset path when changing stores.
     *
     * Lifted from Illuminate\Routing\RoutingServiceProvider
     */
    protected function overrideUrlGenerator(): void
    {
        $this->app->singleton('url', function ($app) {
            $routes = $app['router']->getRoutes();

            // The URL generator needs the route collection that exists on the router.
            // Keep in mind this is an object, so we're passing by references here
            // and all the registered routes will be available to the generator.
            $app->instance('routes', $routes);

            return new UrlGenerator(
                $routes, $app->rebinding(
                    'request', $this->requestRebinder()
                ), $app['config']['app.asset_url']
            );
        });
    }

    /**
     * Get the URL generator request rebinder.
     * Lifted from Illuminate\Routing\RoutingServiceProvider
     *
     * @return \Closure
     */
    protected function requestRebinder()
    {
        return function ($app, $request) {
            $app['url']->setRequest($request);
        };
    }
}