View injections

The view injections are designed to provide a standardized way to pass parameters to the common layer

of views in an application. Implementing this interface allows developers to manage the data that will be available across various views, ensuring flexibility and reusability of code.

Configuration

In config params.php:

...
'yiisoft/yii-view' => [
        'injections' => [
            Reference::to(ContentViewInjection::class),
            Reference::to(CsrfViewInjection::class),
            Reference::to(LayoutViewInjection::class),
        ],
    ],

New injections

Start by defining a class that will implement the Yiisoft\Yii\View\Renderer\CommonParametersInjectionInterface. This class will be responsible for providing the parameters you want to inject into your view templates and layouts.

class MyCustomParametersInjection implements Yiisoft\Yii\View\Renderer\CommonParametersInjectionInterface
{
    // Class properties and methods will go here

    public function __construct(UserService $userService)
    {
        $this->userService = $userService;
    }

    public function getCommonParameters(): array
    {
        return [
            'siteName' => 'My Awesome Site',
            'currentYear' => date('Y'),
            'user' => $this->userService->getCurrentUser(),
        ];
    }
}

Add your new Injection to params.php:

'yiisoft/yii-view' => [
        'injections' => [
            ...,
            Reference::to(MyCustomParametersInjection::class),
        ],
    ],

Using Separate Injections for Different Layouts

If your application has multiple layouts, you can create separate parameter injections for each layout. This approach allows you to tailor the parameters injected into each layout according to its specific needs, enhancing the flexibility and maintainability of your application.

Create your custom ViewInjection for specific layout:

readonly final class CartViewInjection implements CommonParametersInjectionInterface
{
    public function __construct(private Cart $cart)
    {
    }

    public function getCommonParameters(): array
    {
        return [
            'cart' => $this->cart,
        ];
    }
}

Add your new injection to params.php under specific layout name. In the following example, it is @layout/cart:

'yiisoft/yii-view' => [
        'injections' => [
            ...,
            Reference::to(MyCustomParametersInjection::class),
            DynamicReference::to(static function (ContainerInterface $container) {
                $cart = $container
                    ->get(Cart::class);

                return new LayoutSpecificInjections(
                    '@layout/cart', // layout name for injection

                    new CartViewInjection($cart)
                );
            }),
        ],
    ],