Re: [flask] Faking resource and context - question to the document
- Alex Ogier
- 2013-06-11 @ 18:47
This will make a lot more sense after reading the documentation on
contextlib and contextmanager:
Basically what it does is turn a python generator that yields once into an
object that can be used as the argument of a 'with' statement. The 'yield'
here doesn't return anything, its only purpose is to yield control to the
calling function without unwinding the global state it set up with
As for 'sender' and '**kwargs' those are just part of the API of flask
signals, as you suspect. They aren't used here because the user_set
function just operates on the global 'g' object.
On Jun 11, 2013 2:12 PM, "sean chen" <email@example.com> wrote:
> I am reading the document and met a problem here, I wonder if I can get
> help from the community :-)
> from contextlib import contextmanagerfrom flask import appcontext_pushed
> @contextmanagerdef user_set(app, user):
> def handler(sender, **kwargs):
> g.user = user
> with appcontext_pushed.connected_to(handler, app):
> Here I have couple of questions:
> 1) "sender" was never used, neither the "**kwargs", why do we need such
> arguments? -- I guess I need to understand the connected_to function to
> understand this part?
> 2) I did not understand what user_set is trying to do here -- it yields
> no object.
> from flask import json, jsonify
> @app.route('/users/me')def users_me():
> return jsonify(username=g.user.username)
> with user_set(app, my_user):
> with app.test_client() as c:
> resp = c.get('/users/me')
> data = json.loads(resp.data)
> self.assert_equal(data['username'], my_user.username)
> Now, user_set is used in "with", as I did not understand the yield (i.e.,
> what does user_set yield), I guess I don't know what exactly the this whole
> example is doing, though I GUESSed what it tries to do.