graphql-python / flask-graphql

Hi and thanks for the geat job.

With 1.4.1 version I used to pass my DB session via the context option of the GraphQLView as still mentioned in the README (which should be updated).

Below is an exemple of what I was doing:

# [...]

db_session = scoped_session(
    sessionmaker(autocommit=False, autoflush=False, bind=engine))

# [...]

app.add_url_rule(
    '/graphql', view_func=GraphQLView.as_view(
        'graphql', schema=SCHEMA, graphiql=True,
        context={'session': db_session}))

# [...]

It seems this is no more possible and I can't figure out how to pass the DB session to the GraphQLView. Any information and/or updated doc would be nice.

Any solution to continue passing DB session via the GraphQLView (or by any other way allowing to pass it at execution time) would be perfect.

EDIT: for an undocumented but working solution see @cockscomb 's comment

I'm having the same problem. I tried to use context and context_value and neither of them works.

same

There seem to be changes in graphql-server-core and flask-graphql to change unit tests :
"Improved query execution using pluggable backend" in graphql-server-core e.g.:
graphql-python/graphql-server@d60b180

There is an underlying change in graphql-python/graphql-core@f6d79ab
in the commit "Modernize execute function" around graphql-core v2.1.0

This is where "context_value" is deprecated for "context"

graphql-python/graphql-core@f6d79ab

It looks like "context" is now not what is being passed by the user of flask-graphql, but a Request object instead. Maybe there is a name collision in flask-graphql?

It looks like the breaking change was actually a long time ago, but was only put out in a full release recently:

d728f80

I don't know if the behaviour of "context_value" was meant to go away and the documentation was left unchanged?

Edit: This also seems to be referenced in the last comment (made after merge) of #19

Is there a recommended way to do the things that were done by using context in older versions? I have seen the suggestion to restore the old context behaviour by inheritence. But I guess context was removed for a reason (btw what reason?), so there may be a better way?

Cannot speak to why they would have possibly removed it but I can say for now I just am using this to work around.

class MyGraphQLView(GraphQLView):
   def get_context(self):
       context = super().get_context()
       context.session = db.session

       return context

Ah thanks! This was what I meant by "restore the old context behavior by inheritance".

I found a test case of passing context.

flask-graphql/tests/test_graphqlview.py

Line 454 in 4183613

    
           @pytest.mark.parametrize('app', [create_app(get_context=lambda:"CUSTOM CONTEXT")])

I succeeded passing custom context in the following way.

app.add_url_rule(
    '/graphql', view_func=GraphQLView.as_view(
        'graphql', schema=SCHEMA, graphiql=True,
        get_context=lambda: {'session': db_session}))

@cockscomb It works perfectly thanks for sharing this

passing context to GraphQLView no more supported?