id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
20744	Docs imply that forms.Field.__init__ accepts any keyword arguments	Gunnlaugur Þór Briem	Adam Zapletal	"At https://docs.djangoproject.com/en/dev/ref/forms/fields/ there is this:

{{{
class Field(**kwargs)
}}}

with no stated constraints on `kwargs`, thus implying (incorrectly) that any keyword argument can safely be passed to the `forms.Field` constructor.

That leads to code which worked in previous Django versions but regresses in the current version. The case I have in mind is [https://github.com/jezdez/django-authority/blob/11461f808160e09bb992f9c602c342718892bb6a/authority/admin.py#L28-L33 in django-authority's admin.py] where the `kwargs` passed to `formfield_callback` (which can include `request`) are passed on to `Field.formfield`, whose documentation says “All of the `kwargs` dictionary is passed directly to the form field’s `__init__()` method” ... and that `__init__` method ''can't'' include `request`. So upgrading Django yields this somewhat tricky-to-troubleshoot error in a django-authority admin action:

{{{
TypeError: __init__() got an unexpected keyword argument 'request'

  ...
  File ""django/forms/models.py"", line 170, in fields_for_model
    formfield = formfield_callback(f, **kwargs)
  File ""authority/admin.py"", line 33, in formfield_for_dbfield
    return db_field.formfield(**kwargs)
  File ""django/db/models/fields/__init__.py"", line 646, in formfield
    return super(CharField, self).formfield(**defaults)
  File ""django/db/models/fields/__init__.py"", line 499, in formfield
    return form_class(**defaults)
  File ""django/forms/fields.py"", line 188, in __init__
    super(CharField, self).__init__(*args, **kwargs)
}}}

At some point in this chain, the `request` keyword argument must be popped out. Presumably directly before the call to `Field.formfield`. In any case, this requirement should be documented.

(Or `forms.Field.__init__` could be changed to tolerate and ignore unknown keyword arguments. But that's a riskier change.)"	Bug	closed	Documentation	dev	Normal	fixed		Pashkin Adam Zapletal	Ready for checkin	1	0	0	0	0	0