Url

class Cake\View\Helper\UrlHelper(View $view, array $config = [])

The UrlHelper helps you to generate URLs from your other helpers. It also gives you a single place to customize how URLs are generated by overriding the core helper with an application one. See the Aliasing Helpers section for how to do this.

Generating URLs

method Cake\View\Helper\UrlHelper::build($url = null, array $options = [])

Returns a URL pointing to a combination of controller and action. If $url is empty, it returns the REQUEST_URI, otherwise it generates the URL for the controller and action combo. If fullBase is true, the full base URL will be prepended to the result:

echo $this->Url->build([
    'controller' => 'Posts',
    'action' => 'view',
    'bar',
]);

// Output
/posts/view/bar

Here are a few more usage examples:

URL with extension:

echo $this->Url->build([
    'controller' => 'Posts',
    'action' => 'list',
    '_ext' => 'rss',
]);

// Output
/posts/list.rss

URL with prefix:

echo $this->Url->build([
    'controller' => 'Posts',
    'action' => 'list',
    'prefix' => 'Admin',
]);

// Output
/admin/posts/list

URL (starting with '/') with the full base URL prepended:

echo $this->Url->build('/posts', ['fullBase' => true]);

// Output
http://somedomain.com/posts

URL with GET parameters and fragment anchor:

echo $this->Url->build([
    'controller' => 'Posts',
    'action' => 'search',
    '?' => ['foo' => 'bar'],
    '#' => 'first',
]);

// Output
/posts/search?foo=bar#first

The above example uses the ? special key for specifying query string parameters and # key for URL fragment.

URL for named route:

// Assuming a route is setup as a named route:
// $router->connect(
//     '/products/{slug}',
//     [
//         'controller' => 'Products',
//         'action' => 'view',
//     ],
//     [
//         '_name' => 'product-page',
//     ]
// );

echo $this->Url->build(['_name' => 'product-page', 'slug' => 'i-m-slug']);
// Will result in:
/products/i-m-slug

The 2nd parameter allows you to define options controlling HTML escaping, and whether or not the base path should be added:

$this->Url->build('/posts', [
    'escape' => false,
    'fullBase' => true,
]);

method Cake\View\Helper\UrlHelper::buildFromPath(string $path, array $params = [], array $options = [])

If you want to use route path strings, you can do that using this method:

echo $this->Url->buildFromPath('Articles::index');
// outputs: /articles

echo $this->Url->buildFromPath('MyBackend.Admin/Articles::view', [3]);
// outputs: /admin/my-backend/articles/view/3

URL with asset timestamp wrapped by a <link rel="preload"/>, here pre-loading a font. Note: The file must exist and Configure::read('Asset.timestamp') must return true or 'force' for the timestamp to be appended:

echo $this->Html->meta([
    'rel' => 'preload',
    'href' => $this->Url->assetUrl(
        '/assets/fonts/your-font-pack/your-font-name.woff2'
    ),
    'as' => 'font',
]);

If you are generating URLs for CSS, Javascript or image files there are helper methods for each of these asset types:

// Outputs /img/icon.png
$this->Url->image('icon.png');

// Outputs /js/app.js
$this->Url->script('app.js');

// Outputs /css/app.css
$this->Url->css('app.css');

// Force timestamps for one method call.
$this->Url->css('app.css', ['timestamp' => 'force']);

// Or disable timestamps for one method call.
$this->Url->css('app.css', ['timestamp' => false]);

Customizing Asset URL generation

If you need to customize how asset URLs are generated, or want to use custom asset cache busting parameters you can use the assetUrlClassName option:

// In view initialize
$this->loadHelper('Url', ['assetUrlClassName' => AppAsset::class]);

When using the assetUrlClassName you must implement the same methods as Cake\Routing\Asset does.

For further information check Router::url in the API.