Strip fields' values consistently

[Vlastimil Zíma]

Currently, some fields strips values during validation and some do not. The state does not even clearly represents whether whitespace is valid part of field's value.

Field	Strips	Should strip
CharField	no	no
IntegerField	yes	yes
FloatField	yes	yes
DecimalField	yes	yes
BaseTemporalField	yes	yes
RegexField	no	no
EmailField	yes	yes
URLField	no	yes
BooleanField	no	?
NullBooleanField	no	?
IPAddressField	no	yes
GenericIPAddressField	no	yes
SlugField	no	yes

Comments:

• Spaces are not allowed in URLField, IPAddressField, GenericIPAddressField and SlugField
• Fairly unclear are boolean fields. IMHO if value to validate is string of whitespace characters, it should validate to None/False as when represented by TextInput user will see empty field.

I have not check localised form fields but I expect more fields that can be safely trimmed.

Maybe a good long-term solution would be list of filters (like validators) which would perform transformation to python object.

[Stephen Burrows]

I've actually gotten this as a feature request on projects I've worked on in the wild... I assumed that django just wasn't stripping any field values of whitespace. But it is, either implicitly or explicity. It would be good to be consistent. So it would make sense (to me) to strip whitespace on !URLField, !IPAddressField, !GenericIPAddressField, and SlugField - maybe leave the BooleanFields for later/never, since the case isn't clear.

[Lebedev Ilya]

Added stripping for URLField, IPAddressField, GenericIPAddressField, SlugField. I have two questions: is it all that should be done? Why no tests are required?

[Claude Paroz]

Note that this has been fixed for IPAddressField/GenericIPAddressField in #17751.

[Aymeric Augustin]

PR: ​https://github.com/django/django/pull/1113

[Aymeric Augustin <aymeric.augustin@…>]

In 7d050e8e9ce0e08aefe035a7e203c764fbfb544b:

Merge pull request #1113 from denibertovic/master

Fixed #18761 -- Added whitespace stripping to URLField and SlugField.