Middleware

This is the core of ArcStack Django API. The Endpoint is no different than View class of Django without any middleware defined.

The middleware system is a shallow copy of the Django middleware system. This is to ensure that when a new middleware needs to be created you don't need to learn a complex system.

If you did not meddle into Django Middleware system yet, I suggest to read its documentation first.

IMPORTANT: There is no async support yet.

Defining Middleware

The middleware definiton can be changed in Django settings. The setting variable name is API_MIDDLEWARE.

ArcStack Django API comes with following setting as default:

API_MIDDLEWARE = [
    "arcstack_api.middleware.CommonMiddleware",
]

Differences from Django Middleware

ArcStack API Middleware works same with Django middleware but there are some differences that you need to be aware of.

Request object

The ArcStack API defines a _arcstack_meta attribute to the incoming HttpRequest object. This object stores the endpoint function and args and kwargs passed from the Django.

Django, at the end of the middleware chain, resolves request to get the view function and generates args and kwargs to pass to the view function. These parameters are path parameters.

ArcStack API does not re-resolve requests since it is wasteful to do the same operation twice. Instead, it generates a meta object to store the view function, args and kwargs and attaches it to request object. This _arcstack_meta object is removed from the request just before calling process_endpoint and endpoint functions.

Django middleware hooks

Django has some special hooks in the middleware system. For more information, you can visit the Django documentation

Use process_endpoint instead of process_view

process_view() middleware hook renamed to process_endpoint but behaves the same. This hook especially useful if you want to have a functionality same as Django Ninja.

No process_template_response() hook

process_template_response() hook has no use for API endpoints.