Containers

Provided Factories

Expressive provides several factories compatible with PSR-11 Container 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 Psr\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\Delegate\DefaultDelegate. This should return an Interop\Http\ServerMiddleware\DelegateInterface instance to process when the middleware pipeline is exhausted without returning a response; by default, this will be a Zend\Expressive\Delegate\NotFoundDelegate instance.
- 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 may be used to seed the application instance with 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:

programmatic_pipeline (bool) (Since 1.1.0): when enabled, middleware_pipeline and routes configuration are ignored, and the factory will assume that these are injected programmatically elsewhere.
raise_throwables (bool) (Since 1.1.0; obsolete as of 2.0.0): when enabled, this flag will prevent the Stratigility middleware dispatcher from catching exceptions, and instead allow them to bubble outwards.
middleware_pipeline can be used to seed the middleware pipeline:

  'middleware_pipeline' => [
      // An array of middleware to register.
      [ /* ... */ ],

      // Expressive 1.0:
      Zend\Expressive\Container\ApplicationFactory::ROUTING_MIDDLEWARE,
      Zend\Expressive\Container\ApplicationFactory::DISPATCH_MIDDLEWARE,

      // Expressive 1.1 and above (above constants will still work, though):
      Zend\Expressive\Application::ROUTING_MIDDLEWARE,
      Zend\Expressive\Application::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, valid middleware, or an array of these',
      // optional:
      'path'  => '/path/to/match',
      'priority' => 1, // Integer

      // optional under Expressive 1.X; ignored under 2.X:
      'error' => false, // boolean
  ],

The middleware key itself is the middleware to execute, and must be a service name resolving to valid middleware, middleware instances (either http-interop middleware or callable double-pass middleware), or an array of these values. If an array is provided, the specified middleware will be composed into a Zend\Stratigility\MiddlewarePipe instance.

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).

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.

Under Expressive 1.X, 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.) We recommend not using this feature; see the chapter on error handling for details.

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, valid middleware, or array of these values',
          '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 service name resolving to valid middleware, valid
  middleware (either http-interop middleware or callable double-pass
  middleware), or an array of such values (which will be composed into
  a `Zend\Stratigility\MiddlewarePipe` instance); this middleware will be
  dispatched 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.)

ErrorHandlerFactory

Provides: Zend\Stratigility\Middleware\ErrorHandler
Suggested Name: Zend\Stratigility\Middleware\ErrorHandler
Requires: no additional services are required.
Optional:
- Zend\Expressive\Middleware\ErrorResponseGenerator. If not provided, the error handler will not compose an error response generator, making it largely useless other than to provide an empty response.

ErrorResponseGeneratorFactory

Provides: Zend\Expressive\Middleware\ErrorResponseGenerator
Suggested Name: Zend\Stratigility\Middleware\ErrorResponseGenerator
Requires: no additional services are required.
Optional:
- Zend\Expressive\Template\TemplateRendererInterface. If not provided, the error response generator will provide a plain text response instead of a templated one.
- config, an array or ArrayAccess instance. This will be used to seed the ErrorResponseGenerator instance with a template name to use for errors (see more below), and/or a "debug" flag value.

When the config service is present, the factory can utilize two values:

debug, a flag indicating whether or not to provide debug information when creating an error response.
zend-expressive.error_handler.template_error, a name of an alternate template to use (instead of the default represented in the Zend\Expressive\Middleware\ErrorResponseGenerator::TEMPLATE_DEFAULT constant).

As an example:

'debug' => true,
'zend-expressive' => [
    'error_handler' => [
        'template_error' => 'name of error template',
    ],
],

NotFoundDelegateFactory

Provides: Zend\Expressive\Delegate\NotFoundDelegate
Suggested Name: Zend\Expressive\Delegate\NotFoundDelegate, and aliased to Zend\Expressive\Delegate\DefaultDelegate.
Requires: no additional services are required.
Optional:
- Zend\Expressive\Template\TemplateRendererInterface. If not provided, the delegate will provide a plain text response instead of a templated one.
- config, an array or ArrayAccess instance. This will be used to seed the NotFoundDelegate instance with a template name to use.

When the config service is present, the factory can utilize two values:

zend-expressive.error_handler.template_404, a name of an alternate template to use (instead of the default represented in the Zend\Expressive\Delegate\NotFoundDelegate::TEMPLATE_DEFAULT constant).

As an example:

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

NotFoundHandlerFactory

Provides: Zend\Expressive\Middleware\NotFoundHandler
Suggested Name: Zend\Expressive\Middleware\NotFoundHandler
Requires: Zend\Expressive\Delegate\DefaultDelegate

WhoopsErrorResponseGeneratorFactory

Provides: Zend\Expressive\Middleware\WhoopsErrorResponseGenerator
Suggested Name: Zend\Expressive\Middleware\ErrorResponseGenerator
Requires: Zend\Expressive\Whoops (see WhoopsFactory, below)

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.