CheckboxInput should return False if not found

[Chris Beaven]

This is the crux of the problem people are having with BooleanField. A CheckboxInput widget will only ever return something if it's checked. So if it isn't in cleaned_data then it should be assumed False, not None.

[Chris Beaven]

Oops, that's not the right patch yet...

[Chris Beaven]

There, that's better.

I also changed the documentation to get rid of the "No validation" messages because they are confusing. They really mean "No further validation" because the Field validation still applies.

[Chris Beaven]

clarified the test behaviour

[Chris Beaven]

This should be mentioned on ​http://code.djangoproject.com/wiki/BackwardsIncompatibleChanges because some people could be (probably are) relying on the current behaviour of BooleanField (with default widget) raising a ValidationError if the key doesn't exist.

Note: This is still possible to check for, you just have to do it in a clean_* method.

[Philippe Raoult]

#4480 is a duplicate of this one, closed because we have a good patch here.

[Philippe Raoult]

same for #5291

[James Bennett]

Closing #3130 in favor of getting the BooleanField/Checkbox/etc. issues worked out all in one ticket -- this one -- instead of spread out.

[Malcolm Tredinnick]

Okay, I like the approach Chris is taking here and I'm going to commit a small variation on this patch (predominantly, including some more documentation clarifications). I'm not going to remove the "validates nothing" lines in the third patch, since explicitly including them makes it clear we haven't just forgotten to list the validation conditions.

I agree that this will make the natural behaviour clearer for people and I think this should put the issue to rest.

I'm not going to change the current default for BooleanField subclasses to make it required=False because it's not possible to make that sort of change and break existing code, so people writing BooleanField() at the moment will have their validation conditions weakened and might not notice it (we try to make all backwards incompatible changes fatal if you don't notice them). It simply isn't that hard to type required=False to make that risk necessary. A little annoying for some people; hardly fatal, though.

[Malcolm Tredinnick]

(In [6564]) Updated the new default value for BooleanFields, clarified the behaviour of
'required' for those fields and updated the examples to use required=False so
that people get the hint. Refs #5104.

[Malcolm Tredinnick]

[6563] contained the main code changes, but didn't seem to update this ticket automatically.