Opened 7 years ago

Closed 7 years ago

Last modified 5 years ago

#13093 closed (fixed)

cache_page decorator doesn't work on callable classes

Reported by: Russell Keith-Magee Owned by: nobody
Component: Core (Cache system) Version: 1.2-beta
Severity: Keywords:
Cc: Brian Neal Triage Stage: Accepted
Has patch: no Needs documentation: no
Needs tests: no Patch needs improvement: no
Easy pickings: UI/UX:

Description (last modified by Russell Keith-Magee)

The cache_page() decorator works fine on views, but fails if you use it on a callable class::

class MyView(object):
    def __call__(self, request):
        return HttpResponse()

If you try to wrap this view in urls.py ( cache_page(MyView(), 60) ), you get an error saying "MyView doesn't have attribute __name__". cache_page uses the __name__ attribute to build a cache key, but classes dont have a __name__ attribute. cache_page should also check for __class__.__name__ (or some similar key with a per-instance feature) to allow for wrapping callable classes.

This is a problem for 1.2, because feed views have been moved to a class-based structure, so it is no longer possible to cache feed views using cache_page().

Change History (7)

comment:1 Changed 7 years ago by Russell Keith-Magee

Description: modified (diff)
Needs documentation: unset
Needs tests: unset
Patch needs improvement: unset
Triage Stage: UnreviewedAccepted

Forgot to mention: Thanks to Brian Neal for the report.

comment:2 Changed 7 years ago by Brian Neal

Cc: Brian Neal added

comment:3 Changed 7 years ago by Russell Keith-Magee

It turns out that this is actually due to a bug in Python itself; functools.wraps doesn't check to see if an attribute is available before copying it onto the wrapped view. Luckily, the API for wraps includes a feature that can be used as a workaround; a patch should be committed shortly.

comment:4 Changed 7 years ago by Russell Keith-Magee

Resolution: fixed
Status: newclosed

(In [12762]) Fixed #13093 -- Updated some decorators and the decorator_from_middleware function to allow callable classes to be decorated. Thanks to Brian Neal for the report.

comment:5 Changed 7 years ago by Russell Keith-Magee

(In [12763]) [1.1.X] Fixed #13093 -- Updated some decorators and the decorator_from_middleware function to allow callable classes to be decorated. Thanks to Brian Neal for the report.

Backport of r12762 from trunk.

comment:6 Changed 7 years ago by Karen Tracey

The backport to 1.1.X here caused bunches of test errors on 1.1.X. See #13111.

comment:7 Changed 5 years ago by Jacob

milestone: 1.2

Milestone 1.2 deleted

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