* * For the full copyright and license information, please view the LICENSE * file that was distributed with this source code. */ namespace Symfony\Bridge\Twig\Extension; use Symfony\Component\HttpFoundation\RequestStack; use Symfony\Component\WebLink\GenericLinkProvider; use Symfony\Component\WebLink\Link; use Twig\Extension\AbstractExtension; use Twig\TwigFunction; /** * Twig extension for the Symfony WebLink component. * * @author Kévin Dunglas */ final class WebLinkExtension extends AbstractExtension { private $requestStack; public function __construct(RequestStack $requestStack) { $this->requestStack = $requestStack; } /** * {@inheritdoc} */ public function getFunctions(): array { return [ new TwigFunction('link', [$this, 'link']), new TwigFunction('preload', [$this, 'preload']), new TwigFunction('dns_prefetch', [$this, 'dnsPrefetch']), new TwigFunction('preconnect', [$this, 'preconnect']), new TwigFunction('prefetch', [$this, 'prefetch']), new TwigFunction('prerender', [$this, 'prerender']), ]; } /** * Adds a "Link" HTTP header. * * @param string $rel The relation type (e.g. "preload", "prefetch", "prerender" or "dns-prefetch") * @param array $attributes The attributes of this link (e.g. "['as' => true]", "['pr' => 0.5]") * * @return string The relation URI */ public function link(string $uri, string $rel, array $attributes = []): string { if (!$request = $this->requestStack->getMasterRequest()) { return $uri; } $link = new Link($rel, $uri); foreach ($attributes as $key => $value) { $link = $link->withAttribute($key, $value); } $linkProvider = $request->attributes->get('_links', new GenericLinkProvider()); $request->attributes->set('_links', $linkProvider->withLink($link)); return $uri; } /** * Preloads a resource. * * @param array $attributes The attributes of this link (e.g. "['as' => true]", "['crossorigin' => 'use-credentials']") * * @return string The path of the asset */ public function preload(string $uri, array $attributes = []): string { return $this->link($uri, 'preload', $attributes); } /** * Resolves a resource origin as early as possible. * * @param array $attributes The attributes of this link (e.g. "['as' => true]", "['pr' => 0.5]") * * @return string The path of the asset */ public function dnsPrefetch(string $uri, array $attributes = []): string { return $this->link($uri, 'dns-prefetch', $attributes); } /** * Initiates a early connection to a resource (DNS resolution, TCP handshake, TLS negotiation). * * @param array $attributes The attributes of this link (e.g. "['as' => true]", "['pr' => 0.5]") * * @return string The path of the asset */ public function preconnect(string $uri, array $attributes = []): string { return $this->link($uri, 'preconnect', $attributes); } /** * Indicates to the client that it should prefetch this resource. * * @param array $attributes The attributes of this link (e.g. "['as' => true]", "['pr' => 0.5]") * * @return string The path of the asset */ public function prefetch(string $uri, array $attributes = []): string { return $this->link($uri, 'prefetch', $attributes); } /** * Indicates to the client that it should prerender this resource . * * @param array $attributes The attributes of this link (e.g. "['as' => true]", "['pr' => 0.5]") * * @return string The path of the asset */ public function prerender(string $uri, array $attributes = []): string { return $this->link($uri, 'prerender', $attributes); } }