Request Lifecycle for a Mezzio-Based Application

The request lifecycle is the sequence of steps that happen from the moment a user makes an HTTP request until the server sends back a response.

The graph below shows how the request is handled by Dotkernel Light.

Request Lifecycle Step-by-Step

The following list describes what each of the steps from the graph does in Dotkernel Light.

1. HTTP Request [public/index.php]

• Bootstrap the application.
• Load configuration.
• Create the Mezzio application instance.

2. Service Container

Register:

• Factories.
• Aliases.
• Delegators.

All services are configured and ready to use.

3. Route Registration

Read all available routes with their allowed request methods and dynamically register them in the application. Routes are managed by FastRoute.

Example

4. Middleware Pipeline [config/pipeline.php]

Loads the predefined order of middleware. It defines how incoming HTTP requests move through the application and how responses are generated.

5. Routing

FastRoute matches the URL and method against registered routes.

Example

6. Handler Invocation

Extract the matched route name from the request and pass it to the renderer.

$template = $request->getAttribute(RouteResult::class)->getMatchedRouteName();
// $template = 'page::about';

7. Custom Logic Execution in Handler

Execute the business logic in the handler. The process can involve services and any custom logic.

8. Template Rendering

Twig loads the template, applies layout, renders blocks and includes partials.

Example

9. Response Creation

An HtmlResponse is created with status, headers and the rendered HTML body.

Example

10. Response Pipeline

The response flows back through the middleware stack. Middleware can modify headers, cookies, compress content, etc.

11. Response Emitter

The final response is sent back to the browser. The page is rendered and sent to the user.