Prevent crash when a non-numeric value is passed to a ModelSelectField(widget=ModelSelect2Widget(...))

[jieter]

If the form value for a ModelSelectField for numeric foreign key is non-numeric, rendering the form
crashes with:

Field 'id' expected a number but got "13'[0]".

(full traceback)

This proposes ignoring non-numeric values for numeric fields. A small test case is included.

[codecov]

Codecov Report

Merging #36 (6b21286) into master (e735be2) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@ Coverage Diff @@ ## master #36 +/- ## ======================================= Coverage 99.57% 99.57% ======================================= Files 7 7 Lines 233 237 +4 ======================================= + Hits 232 236 +4  Misses 1 1 

Impacted Files	Coverage Δ
django_select2/forms.py	100.00% <100.00%> (ø)

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[codingjoe]

Hi @jieter,

A familiar face! Thanks for your contribution, and thanks for providing the stack trace. However, I am struggling to understand where this non-numeric values is coming from.
Maybe you could elaborate a bit more on your setup and this case.

Best,
Joe

[jieter]

Almost 3 years ago already!

We use the widget as part of a django-filter filterset. I'm not sure why this weird values get in the query string, but crash reporting shows lots of crashes related to this.

When I use the default widget for ModelSelectField and pass a non-numeric value, the form is considered invalid (which is different from what I propose here), and rendered as such. But it does not result in a crash.

In my opinion it is a reasonable expectation for this widget not to crash. Dealing with the origin of the weird values might become a little harder, but the UI should make clear to the user that no item is selected in the widget.

[codingjoe]

I see, hm… If this comes from a programmatic error I am hesitant to silence the error. To my knowledge a user can't pass a non-numeric value, only a developer can. I would agree to maybe provide a better exception message, to silence it, seems wrong. Besides, I just explained in another post, why cleaning value for a primary key in Django is almost impossible, since all different field types raise different errors.