DateTimeField cannot validate isoformat() datetime strings.

[Keryn Knight]

given:

from datetime import datetime
dt = datetime.now()
formatted = dt.isoformat()
f = forms.DateTimeField()
f.clean(value=formatted)

a ValidationError will be raised because the default sep for isoformat is T and that format isn't in the default DATETIME_INPUT_FORMATS.

I came across this while looking to serialize a form.cleaned_data dictionary to JSON using the internal DjangoJSONEncoder - to work around it in what is ostensibly a re-usable app, I had to subclass the DjangoJSONEncoder to handle datetimes before going to the super()

I have a unit test and patch available, if accepted.

[Tim Graham]

I can't immediately think of anything that could go wrong.

[Tim Graham]

As noted on the pull request, it seems this would only work with USE_L18N = False. Should we add it all locale's formats.py? I'm not sure. At least documentation is needed.

[Keryn Knight]

Given the need to touch at least 40 locales files, and presumably write at least N further tests to cover those, I'm inclined to say kick the ticket to DDN and see if it ever gets at least +0, rather than spend further time refining it.

[Tim Graham]

We removed the "Design Decision Needed" triage stage since that's where tickets went to die. If you want to write to the mailing list to get feedback on this, please do that. Otherwise, it's probably better to close the ticket rather than leave it open without a clear path to resolution.

[Tim Graham]

Marking as "won't fix" until someone is motivated to write to the mailing list and argue for this change or propose an alternate solution.

[Tim Graham]

See also #11385 and #23448.