Opened 8 years ago

Last modified 8 years ago

#18538 closed Bug

type(SimpleLazyObject) returns SimpleLazyObject rather than type(_wrapped) — at Version 1

Reported by: Jeremy Dunck Owned by: nobody
Component: Database layer (models, ORM) Version: 1.4
Severity: Normal Keywords:
Cc: Triage Stage: Unreviewed
Has patch: no Needs documentation: no
Needs tests: no Patch needs improvement: no
Easy pickings: no UI/UX: no

Description (last modified by Jeremy Dunck)

In 1.4 we introduced request.user as a SimpleLazyObject. This has caused some bugs caused by abstraction leakage.

Today we ran across another - I'm expecting Router.allow_relation to be called with model instances (https://docs.djangoproject.com/en/1.4/topics/db/multi-db/#allow_relation) and using type() to get to the Model subclass.

type(obj1)._meta fails because type(obj1) returns SimpleLazyObject.

I've worked around by calling obj1.class (which is specifically proxied), but I'm nothing the leakage here. I think there's nothing to be done (type is implemented in C (PyObject_Type) and reaches into the python object structure) but I am noting in here in case someone else has a bright idea for fixing it.

At least this ticket can serve as a workaround to others coming across this surprise. :)

Tough call on "component", could be ORM (since router in this case) or .auth (since that's what's Lazy'd).

Change History (1)

comment:1 Changed 8 years ago by Jeremy Dunck

Description: modified (diff)
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