URLs, links and routing

URLS

URL from route

use Drupal\Core\Url;

$url = Url::fromRoute($route_name, $params);

URL from URI

use Drupal\Core\Url;

$url = Url::fromUri('internal:/mypath/to/style.css');

Add options to an existing URL (classes, target, etc)

$url->setOptions([

'attributes' => [

'target' => '_blank',

],

]);

Links

Generate a link

$my_link = \Drupal::service('link_generator')->generate($text, Url $url);

OR

use Drupal\Core\Link;

$renderable_link = Link::fromTextAndUrl($text, Url $url);

Create a link from route (skip having to use Url class)

Link::createFromRoute($text, $route_name, ['arg1' => 'value'], ['attributes' => ['class' => 'use-ajax']]);

Convert above link to render array or link string

$link_render_array = $renderable_link->toRenderable();

$link_string = $renderable_link->toString();

Paths

Get the node from the current path

$node = \Drupal::routeMatch()->getParameter('node');

Get current path

$path = \Drupal::service('path.current')->getPath();

Get path arguments (from path above)

$path_args = explode('/', $path);

Get the current route

$route_name = \Drupal::service('current_route_match')->getRouteName();

Requests

Get the query parameter from a GET request

$name = \Drupal::request()->query->get('name');

Get the parameter from a POST request

$name = \Drupal::request()->request->get('name');

Get the host (ex: www.google.com)

$host = \Drupal::request()->getHost();

Redirect

use Symfony\Component\HttpFoundation\RedirectResponse;

new RedirectResponse(\Drupal::url($route_name));