Containers

Provided Factories

Expressive provides several factories compatible with container-interop to facilitate setting up common dependencies. The following is a list of provided containers, what they will create, the suggested service name, and any additional dependencies they may require.

All factories, unless noted otherwise, are in the Zend\Expressive\Container namespace, and define an __invoke() method that accepts an Interop\Container\ContainerInterface instance as the sole argument.

ApplicationFactory

Provides: Zend\Expressive\Application
Suggested Name: Zend\Expressive\Application
Requires: no additional services are required.
Optional:
- Zend\Expressive\Router\RouterInterface. When provided, the service will be used to construct the Application instance; otherwise, an FastRoute router implementation will be used.
- Zend\Expressive\FinalHandler. This is a meta-service, as the only concrete type required is a callable that can be used as a final middleware in the case that the stack is exhausted before execution ends. By default, an instance of Zend\Stratigility\FinalHandler will be used.
- Zend\Diactoros\Response\EmitterInterface. If none is provided, an instance of Zend\Expressive\Emitter\EmitterStack composing a Zend\Diactoros\Response\SapiEmitter instance will be used.
- config, an array or ArrayAccess instance. This will be used to seed the application instance with pre/post pipeline middleware and/or routed middleware (see more below).

Additionally, the container instance itself is injected into the Application instance.

When the config service is present, the factory can utilize several keys in order to seed the Application instance:

middleware_pipeline can be used to seed the middleware pipeline:

  'middleware_pipeline' => [
      // An array of middleware to register.
      [ /* ... */ ],
      Zend\Expressive\Container\ApplicationFactory::ROUTING_MIDDLEWARE,
      Zend\Expressive\Container\ApplicationFactory::DISPATCH_MIDDLEWARE,
      [ /* ... */ ],
  ],

Each item of the array, other than the entries for routing and dispatch middleware, must be an array itself, with the following structure:

  [
      // required:
      'middleware' => 'Name of middleware service, or a callable',
      // optional:
      'path'  => '/path/to/match',
      'error' => true,
      'priority' => 1, // Integer
  ],

The middleware key itself is the middleware to execute, and must be a callable or the name of another defined service. If the path key is present, that key will be used to segregate the middleware to a specific matched path (in other words, it will not execute if the path is not matched). If the error key is present and boolean true, then the middleware will be registered as error middleware. (This is necessary due to the fact that the factory defines a callable wrapper around middleware to enable lazy-loading of middleware.) The priority defaults to 1, and follows the semantics of SplPriorityQueue: higher integer values indicate higher priority (will execute earlier), while lower/negative integer values indicate lower priority (will execute last). Default priority is 1; use granular priority values to specify the order in which middleware should be piped to the application.

You can specify keys for each middleware specification. These will be ignored by the factory, but can be useful when merging several configurations into one for the application.

routes is used to define routed middleware. The value must be an array, consisting of arrays defining each middleware:

  'routes' => [
      [
          'path' => '/path/to/match',
          'middleware' => 'Middleware Service Name or Callable',
          'allowed_methods' => [ 'GET', 'POST', 'PATCH' ],
          'options' => [
              'stuff' => 'to',
              'pass'  => 'to',
              'the'   => 'underlying router',
          ],
      ],
      // etc.
  ],

Each route requires:

- `path`: the path to match. Format will be based on the router you choose for
  your project.

- `middleware`: a callable or a service name for the middleware to execute
  when the route matches.

Optionally, the route definition may provide:

- `allowed_methods`: an array of allowed HTTP methods. If not provided, the
  application assumes any method is allowed.

- `name`: if not provided, the path will be used as the route name (and, if
  specific HTTP methods are allowed, a list of those).

- `options`: a key/value set of additional options to pass to the underlying
  router implementation for the given route. (Typical use cases include
  passing constraints or default values.)

TemplatedErrorHandlerFactory

Provides: Zend\Expressive\TemplatedErrorHandler
Suggested Name: Zend\Expressive\FinalHandler
Requires: no additional services are required.
Optional:
- Zend\Expressive\Template\TemplateRendererInterface. If not provided, the error handler will not use templated responses.
- config, an array or ArrayAccess instance. This will be used to seed the TemplatedErrorHandler instance with template names to use for errors (see more below).

When the config service is present, the factory can utilize the zend-expressive top-level key, with the error_handler second-level key, to seed the Templated instance:

'zend-expressive' => [
    'error_handler' => [
        'template_404'   => 'name of 404 template',
        'template_error' => 'name of error template',
    ],
],

WhoopsErrorHandlerFactory

Provides: Zend\Expressive\TemplatedErrorHandler
Suggested Name: Zend\Expressive\FinalHandler
Requires:
- Zend\Expressive\Whoops, which should provide a Whoops\Run instance.
- Zend\Expressive\WhoopsPageHandler, which should provide a Whoops\Handler\PrettyPageHandler instance.
Optional:
- Zend\Expressive\Template\TemplateRendererInterface. If not provided, the error handler will not use templated responses.
- config, an array or ArrayAccess instance. This will be used to seed the instance with template names to use for errors (see more below).

This factory uses config in the same way as the TemplatedErrorHandlerFactory.

WhoopsFactory

Provides: Whoops\Run
Suggested Name: Zend\Expressive\Whoops
Requires:
- Zend\Expressive\WhoopsPageHandler
Optional:
- config, an array or ArrayAccess instance. This will be used to seed additional page handlers, specifically the JsonResponseHandler (see more below).

This factory creates and configures a Whoops\Run instance so that it will work properly with Zend\Expressive\Application; this includes disabling immediate write-to-output, disabling immediate quit, etc. The PrettyPageHandler returned for the Zend\Expressive\WhoopsPageHandler service will be injected.