maya-chen/flask
1
0
Fork 0
forked from orbit-oss/flask
Code Pull requests Activity

Merge branch '2.3.x'

Browse source
This commit is contained in:
David Lord 2023-08-16 14:30:03 -07:00
commit 9e9acfb3fe
No known key found for this signature in database
GPG key ID: 7A1C87E3F5BC42A8
1 changed files with 29 additions and 26 deletions
Download patch file Download diff file Expand all files Collapse all files

55
docs/patterns/appdispatch.rst
View file

@ -18,34 +18,20 @@ Working with this Document
-------------------------- --------------------------
Each of the techniques and examples below results in an ``application`` Each of the techniques and examples below results in an ``application``
object that can be run with any WSGI server. For production, see object that can be run with any WSGI server. For development, use the
:doc:`/deploying/index`. For development, Werkzeug provides a server ``flask run`` command to start a development server. For production, see
through :func:`werkzeug.serving.run_simple`:: :doc:`/deploying/index`.
from werkzeug.serving import run_simple .. code-block:: python
run_simple('localhost', 5000, application, use_reloader=True)
Note that :func:`run_simple <werkzeug.serving.run_simple>` is not intended for
use in production. Use a production WSGI server. See :doc:`/deploying/index`.
In order to use the interactive debugger, debugging must be enabled both on
the application and the simple server. Here is the "hello world" example with
debugging and :func:`run_simple <werkzeug.serving.run_simple>`::
from flask import Flask from flask import Flask
from werkzeug.serving import run_simple
app = Flask(__name__) app = Flask(__name__)
app.debug = True
@app.route('/') @app.route('/')
def hello_world(): def hello_world():
return 'Hello World!' return 'Hello World!'
if __name__ == '__main__':
run_simple('localhost', 5000, app,
use_reloader=True, use_debugger=True, use_evalex=True)
Combining Applications Combining Applications
---------------------- ----------------------
@ -58,7 +44,9 @@ are combined by the dispatcher middleware into a larger one that is
dispatched based on prefix. dispatched based on prefix.
For example you could have your main application run on ``/`` and your For example you could have your main application run on ``/`` and your
backend interface on ``/backend``:: backend interface on ``/backend``.
.. code-block:: python
from werkzeug.middleware.dispatcher import DispatcherMiddleware from werkzeug.middleware.dispatcher import DispatcherMiddleware
from frontend_app import application as frontend from frontend_app import application as frontend
@ -89,7 +77,9 @@ the dynamic application creation.
The perfect level for abstraction in that regard is the WSGI layer. You The perfect level for abstraction in that regard is the WSGI layer. You
write your own WSGI application that looks at the request that comes and write your own WSGI application that looks at the request that comes and
delegates it to your Flask application. If that application does not delegates it to your Flask application. If that application does not
exist yet, it is dynamically created and remembered:: exist yet, it is dynamically created and remembered.
.. code-block:: python
from threading import Lock from threading import Lock
@ -117,7 +107,9 @@ exist yet, it is dynamically created and remembered::
return app(environ, start_response) return app(environ, start_response)
This dispatcher can then be used like this:: This dispatcher can then be used like this:
.. code-block:: python
from myapplication import create_app, get_user_for_subdomain from myapplication import create_app, get_user_for_subdomain
from werkzeug.exceptions import NotFound from werkzeug.exceptions import NotFound
@ -143,10 +135,12 @@ Dispatch by Path
Dispatching by a path on the URL is very similar. Instead of looking at Dispatching by a path on the URL is very similar. Instead of looking at
the ``Host`` header to figure out the subdomain one simply looks at the the ``Host`` header to figure out the subdomain one simply looks at the
request path up to the first slash:: request path up to the first slash.
.. code-block:: python
from threading import Lock from threading import Lock
from werkzeug.wsgi import pop_path_info, peek_path_info from wsgiref.util import shift_path_info
class PathDispatcher: class PathDispatcher:
@ -166,15 +160,24 @@ request path up to the first slash::
return app return app
def __call__(self, environ, start_response): def __call__(self, environ, start_response):
app = self.get_application(peek_path_info(environ)) app = self.get_application(_peek_path_info(environ))
if app is not None: if app is not None:
pop_path_info(environ) shift_path_info(environ)
else: else:
app = self.default_app app = self.default_app
return app(environ, start_response) return app(environ, start_response)
def _peek_path_info(environ):
segments = environ.get("PATH_INFO", "").lstrip("/").split("/", 1)
if segments:
return segments[0]
return None
The big difference between this and the subdomain one is that this one The big difference between this and the subdomain one is that this one
falls back to another application if the creator function returns ``None``:: falls back to another application if the creator function returns ``None``.
.. code-block:: python
from myapplication import create_app, default_app, get_user_for_prefix from myapplication import create_app, default_app, get_user_for_prefix