In my unittest I need to add a variable to the session, because that variable is used in the view which is being tested. The django documentation says this is possible in the following way (https://docs.djangoproject.com/en/1.3/topics/testing/#django.test.client.Client.session):
def test_something(self):
session = self.client.session
session['somekey'] = 'test'
session.save()
This code example actually doesn't work, because you will get the error that a dict doesn't have a function save. I also tried various other ways to change the contents inside the session dict, but haven't found a way to change it yet.
I know what it means, what i get back is a dict object so it doesnt have the save function. But the session dict also doesn't update when adding keys.
The documentation statues when using self.client.session it should return a SessionStore object instead of a dictionary.
Seems right now there is a bug in Django, so it doesn't work for unauthenticated users to change the session. This is the corresponding ticket: https://code.djangoproject.com/ticket/11475 .
A work around is to create a dummy view in which the session variables are set and calling that view with the Client.get('url_of_dummy_view').
The ticket referenced by #Sam Stoelinga has been closed as a duplicate. The corresponding ticket can be found here.
To save session data you will have to use an authenticated user. I found a solution here.
class BlogAdminTestCase(TestCase):
def setUp(self):
# Setup Test User
User.objects.create_user(
username='foo',
password='bar'
)
# Must login to modify session variables
self.client.login(username='foo', password='bar')
s = self.client.session
s['my_session_variable'] = 'Yay!'
s.save()
Related
I want to set a specific variable when the app STARTS. I may need to edit this variable later on. How can I do this?
I know global variables are bad to use because all users will be affected by one user modifying a global. Is it bad practice to edit a configuration value (I remember reading that somewhere)? If so, what's the best way to do this?
My use case is setting the MongoDB collection name. The user may need to change the collection they're using based on the type of analysis they want to perform.
Since it's specific to each user, store it in the session. If it's not in the session, use the default.
from flask import request, session
#app.route('/change_collection', methods=['POST'])
def change_collection():
session['collection'] = request.form['name']
return '', 204
def get_collection():
name = session.get('collection', 'default')
return my_data[name]
I want to access a session variable from a model, in order to customize what gets shown in a template using {{item.seller_email}}. relevant code from models.py:
SESSION_STORE = import_module(settings.SESSION_ENGINE).SessionStore
class Item(Action):
def seller_email(self):
seller = self.get_seller()
session = SESSION_STORE()
debug('session: %s' % vars(session))
viewer = fetch(Client, email = session.get('client', None))
administrator = viewer.is_admin() if viewer else False
debug('viewer: %s, administrator: %s' % (viewer, administrator))
if administrator:
return seller.email
else:
return seller.anonymized[16:]
the answer here seems to say that this is not possible nor desired, but I lack the understanding of Django's session mechanism to be sure: Access session / request information outside of views in Django
this seems to indicate that the current session can be retrieved outside of views, though, just by not passing a key: https://docs.djangoproject.com/en/1.6/topics/http/sessions/#using-sessions-out-of-views, but I've tried it both that way and the above way with the same results: an "empty" session is created.
I'm sure there are other, better ways of doing this, and I will find one myself, but can someone familiar with Django internals explain why this is not possible?
Because the model shouldn't know anything about session, that creates unnecessary entanglement(?) beetween different components and violation of MVC pattern.
What I suggest to do, is to call the function, specifying parameters needed to get a proper result, viewer object in this case.
If using the code in the question, how do you expect your model to work if it's used in a management command (where there is no http request and as a result no session) ?
Or from a celery job ?
I'm relying on some session data for my django tests.
I was wondering if i could still do that or if i need to rethink my logic.
Anyway, i'm trying to set the session data like this:
self.client.session['last_page_id'] = unicode(self.t1_p5.id)
response = self.client.post(final_page_path, final_page_answers,
follow=True)
So not only is the self.client.session attribute an "empty" after the assignment, but also my session is actually empty at the time it is being used - and yes the value assigned does indeed exist - no AttributeError is raised.
[EDIT]
django version 1.6
I don't know which version of Django you use but in some old docs it is written:
To modify the session and then save it, it must be stored in a variable first (because a new SessionStore is created every time this property is accessed):
Example:
def test_something(self):
session = self.client.session
session['somekey'] = 'test'
session.save()
docs
I am trying to delete an entry from my table. This is my code for the delete function.
#app.route("/delete_link/<link_id>", methods=['GET', 'POST'])
def delete_link(link_id):
link = models.Link.query.filter(models.Link.l_id == link_id).first()
db.session.delete(link)
db.session.commit()
return flask.redirect(flask.url_for('links'))
the line: db.session.delete(link) returns me this error:
InvalidRequestError: Object '' is already attached to session '1' (this is '2')
I've tried this code as well:
#app.route("/delete_link/<link_id>", methods=['GET', 'POST'])
def delete_link(link_id):
link = models.Link.query.filter(models.Link.l_id == link_id)
link.delete()
db.session.commit()
return flask.redirect(flask.url_for('links'))
which does not update the database. Link must not be in the session I guess, but I don't know how to check that, and how to fix it.
I am new to sqlalchemy.
EDIT:
I use this to create my db variable which probably creates the session at this stage (this is at the top of the code). It comes from the flask documentation
from yourapplication import db
You are creating 2 instances of the db object, inherently creating 2 different sessions.
In models.py:
...
5. from config import app
6.
7. db = SQLAlchemy(app)
In erika.py:
...
16. from config import app
...
23. db = SQLAlchemy(app)
then when you try to delete the element:
link = models.Link.query.filter(models.Link.l_id == link_id).first()
db.session.delete(link)
db.session.commit()
the following happens:
models.Link.query uses the database session created by models.py to get the record.
db.session.delete uses the session created by erika.py.
link is attached to the models.py session and you can't use another session (erikas.py) to delete it. Hence:
InvalidRequestError: Object '' is already attached to session '1' (this is '2')
Solution
The solution it's simple. Have only one instance of a db object at any time and reuse that instance whenever you need db operations.
erika.py
from models import db
This way you are always using the same session that was used to fetch your records.
It appears to be a similar problem to the one described at http://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-xvi-debugging-testing-and-profiling
It's a good in-depth description of the problem and how he solved it. The author of that article made a fix that's available as a fork.
The Fix
To address this problem we need to find an alternative way of attaching Flask-WhooshAlchemy's query object to the model.
The documentation for Flask-SQLAlchemy mentions there is a model.query_class attribute that contains the class to use for queries. This is actually a much cleaner way to make Flask-SQLAlchemy use a custom query class than what Flask-WhooshAlchemy is doing. If we configure Flask-SQLAlchemy to create queries using the Whoosh enabled query class (which is already a subclass of Flask-SQLAlchemy's BaseQuery), then we should have the same result as before, but without the bug.
I have created a fork of the Flask-WhooshAlchemy project on github where I have implemented these changes. If you want to see the changes you can see the github diff for my commit, or you can also download the fixed extension and install it in place of your original flask_whooshalchemy.py file.
I defined a simple class in GAE for keeping user profiles data like this:
class User(db.Model):
email = db.EmailProperty()
role = db.StringProperty(default=roles.USER)
first_name = db.StringProperty()
last_name = db.StringProperty()
...
I use memcache to keep session information. memcache data looks like this { 'key': 'agpjYW5kaXJhdGVzcgoLEgRVc2VyGCMM'}. I get session_id value from the cookie. When I try to get user info linked to that cookie like this:
session_id = request['session_id']
data = memcache.get(session_id)
user = User.get(data['key'])
I get KindError exception:
KindError: Kind 'User' is not a subclass of kind 'User'
I know this user exists, memcache exists. User class is defined only once in my project. Why this error occurs and how can I make it work?
UPDATE: I tried to use db.get() instead of User.get() and it worked. So, what's the problem there can be?
Model.get() does check whether the supplied key is of the correct kind, as defined in the documentation. If not of the correct kind it will throw a KindError.
db.get() does not do any type checking and therefore will succeed with the supplied value if it exists in the data store, but will not necessarily return a User entity.
So you need to check whether the key in your memcache is actually of the User kind. Are you sure it's not overwritten with the key of a different model at some point?
The App Engine framework defines a class called 'User' as part of the Users API. In addition, you have your own class by the same name. When the exception occurs, you're trying to use one, but getting the other.
To avoid this, rename your model. You should also be careful how you import modules in Python. Instead of:
from google.appengine.api.users import User
or worse:
from google.appengine.api.users import *
you should use:
from google.appengine.api import users
And then refer to users.User, which is unambiguous.
The problem, it seems to me, is more subtle than that. I was getting the error with this call to Model.get() (I'm retrieving a top-level singleton object, always there):
datastore = GDSDatastore.get(gds.Key.from_path(*path))
so I investigated with this code:
datastore = gds.get(gds.Key.from_path(*path))
if not(datastore is None or isinstance(datastore, GDSDatastore)):
logger.error("KindError isinstance(GDSDatastore)=%s class=%s" % (isinstance(datastore, GDSDatastore), datastore.__class__.__name__))
raise gds.KindError('Kind %r is not a GDSDatastore instance' %
(datastore.kind()))
The vast majority of the time I get no error, but today I got this interesting log:
KindError isinstance(GDSDatastore)=False class=GDSDatastore
Now, that strikes me as rather peculiar.
(Note: GDSDatastore is defined locally: class GDSDatastore(gds.Model))