Confusing error message when ModelForm does not have model set

[Erik Allik]

When instantiating a ModelForm whose Meta.model has not been set (i.e. the ModelForm class was extended instead of Form), the exception message is:

'NoneType' object is not callable

This message originates from django/forms/models.py in __init__ line 218 that says self.instance = opts.model().

Adding an if there with a decent message such as "Model class not set for ModelForm" would be the fix.

[Tobias McNulty]

reviewing patch

[Tobias McNulty]

Works as intended. My personal preference is for unit tests, but that might just be me. Also the exception could be made more specific (AttributeError? ValueError?).

Otherwise, this seems like a simple, intuitive fix to an obscure error.

[Tobias McNulty]

I have a slight preference for the unittest/ValueError way but I'm not sure which patch makes the most sense in the bigger scheme of things

[Peter Bengtsson]

I think 12285.diff is good. Applied it and it works fine.
The module already raises Exception errors on a bunch of other things and the tests are already a doctest.

Raising Exception is IMHO a bad practice since it's not very explicit. A custom defined error would be much better.

[Tobias McNulty]

updated patch uses 'is None' and applies against trunk

[Tobias McNulty]

per jkocherhans

[Tobias McNulty]

also fixes #12051

[jkocherhans]

(In [12526]) Fixed #12285. ModelForm raises a more informative error if it doesn't have a model class defined. Thanks, tobias.

[jkocherhans]

(In [12530]) [1.1.X] Fixed #12285. ModelForm raises a more informative error if it doesn't have a model class defined. Backport of [12526] from trunk.

[Jacob]

Milestone 1.2 deleted