You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
79 lines
2.5 KiB
Python
79 lines
2.5 KiB
Python
"""
|
|
Application Dispatcher
|
|
======================
|
|
|
|
This middleware creates a single WSGI application that dispatches to
|
|
multiple other WSGI applications mounted at different URL paths.
|
|
|
|
A common example is writing a Single Page Application, where you have a
|
|
backend API and a frontend written in JavaScript that does the routing
|
|
in the browser rather than requesting different pages from the server.
|
|
The frontend is a single HTML and JS file that should be served for any
|
|
path besides "/api".
|
|
|
|
This example dispatches to an API app under "/api", an admin app
|
|
under "/admin", and an app that serves frontend files for all other
|
|
requests::
|
|
|
|
app = DispatcherMiddleware(serve_frontend, {
|
|
'/api': api_app,
|
|
'/admin': admin_app,
|
|
})
|
|
|
|
In production, you might instead handle this at the HTTP server level,
|
|
serving files or proxying to application servers based on location. The
|
|
API and admin apps would each be deployed with a separate WSGI server,
|
|
and the static files would be served directly by the HTTP server.
|
|
|
|
.. autoclass:: DispatcherMiddleware
|
|
|
|
:copyright: 2007 Pallets
|
|
:license: BSD-3-Clause
|
|
"""
|
|
import typing as t
|
|
|
|
if t.TYPE_CHECKING:
|
|
from _typeshed.wsgi import StartResponse
|
|
from _typeshed.wsgi import WSGIApplication
|
|
from _typeshed.wsgi import WSGIEnvironment
|
|
|
|
|
|
class DispatcherMiddleware:
|
|
"""Combine multiple applications as a single WSGI application.
|
|
Requests are dispatched to an application based on the path it is
|
|
mounted under.
|
|
|
|
:param app: The WSGI application to dispatch to if the request
|
|
doesn't match a mounted path.
|
|
:param mounts: Maps path prefixes to applications for dispatching.
|
|
"""
|
|
|
|
def __init__(
|
|
self,
|
|
app: "WSGIApplication",
|
|
mounts: t.Optional[t.Dict[str, "WSGIApplication"]] = None,
|
|
) -> None:
|
|
self.app = app
|
|
self.mounts = mounts or {}
|
|
|
|
def __call__(
|
|
self, environ: "WSGIEnvironment", start_response: "StartResponse"
|
|
) -> t.Iterable[bytes]:
|
|
script = environ.get("PATH_INFO", "")
|
|
path_info = ""
|
|
|
|
while "/" in script:
|
|
if script in self.mounts:
|
|
app = self.mounts[script]
|
|
break
|
|
|
|
script, last_item = script.rsplit("/", 1)
|
|
path_info = f"/{last_item}{path_info}"
|
|
else:
|
|
app = self.mounts.get(script, self.app)
|
|
|
|
original_script_name = environ.get("SCRIPT_NAME", "")
|
|
environ["SCRIPT_NAME"] = original_script_name + script
|
|
environ["PATH_INFO"] = path_info
|
|
return app(environ, start_response)
|