HTTP Functions

The @Http annotation simplifies the creation of HTTP endpoint handlers in Dart by providing flexible function signatures and automatic request body deserialization.

Http functions are meant to be used as a replacement for callable Firebase functions and as standalone endpoints.

Function Signatures

The @Http annotation supports four different function signatures, each catering to different use cases:

1. Request-Only Handler

Future<Response> Function(Request request)

This signature provides full access to the raw request object, allowing manual handling of all request aspects including headers, query parameters, and body parsing.

@Http()
Future<Response> updateTodoRequest(Request request) async {
  final todo = await request.body.as(Todo.fromJson);
  // Process the todo...
  return Response.ok('Todo updated: ${todo.id}');
}

2. Request with Logger Handler

Future<Response> Function(Request request, RequestLogger logger)

Similar to the request-only handler but includes a logger parameter for request-specific logging capabilities.

@Http()
Future<Response> updateTodoRequestLogger(
    Request request, RequestLogger logger) async {
  final todo = await request.body.as(Todo.fromJson);
  logger.info('Todo updated: ${todo.id}');
  return Response.ok('Todo updated: ${todo.id}');
}

3. Typed Body Handler

Future<Response> Function(T body)

This signature automatically deserializes the request body into the specified type T, simplifying request handling when only the body is needed.

WARNING

Models must have static or a factory method fromJson(Map<String, dynamic>) available.

You can use libraries like freezed, json_serializable or dart_mappable as long as the method singature is as specified.

@Http()
Future<Response> updateTodo(Todo todo) async {
  // Body is automatically deserialized to Todo
  return Response.ok('Todo updated: ${todo.id}');
}

4. Typed Body with Logger Handler

Future<Response> Function(T body, RequestLogger logger)

Combines automatic body deserialization with logging capabilities.

@Http()
Future<Response> updateTodoLogger(Todo todo, RequestLogger logger) async {
  logger.info('Processing todo update: ${todo.id}');
  return Response.ok('Todo updated: ${todo.id}');
}

⚠️ Current Limitations

1. No Body Validation: The annotation does not currently support automatic request body validation. Validation must be implemented manually within the handler.

2. No Middleware Support: Middleware functionality is not yet available. All request processing must occur within the handler function.

Response Object

All handler functions must return a Future<Response> object. The Response class provides various static methods for common HTTP responses:

// Success responses
Response.ok(body)          // 200 OK
Response.created(body)     // 201 Created

// Error responses
Response.badRequest()      // 400 Bad Request
Response.notFound()        // 404 Not Found
Response.serverError()     // 500 Internal Server Error