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
32286	Definition of JSONField causes issue with validation for a Falsey value	Adam Carruthers	nobody	"I ran into this issue while trying to create a JSONField that would contain a list of strings. The list of strings could have any length. I used the following:


{{{
model_field = models.JSONField(validator=[MyCustomValidator()])
}}}

The validator checks that the object is a list of strings along with some other stuff.

However, under this configuration, `[]` was not a valid entry because it was falsey and hence it failed the `blank=False` test.

So I set `blank=True` on the field to allow for `[]`. But this led to the problem that if you have a falsey value then the validators aren't run. So I was able to set the field to be `null` on the admin site and it was permitted. But I really don't want to allow `null` as a value for fear of causing bugs in my code that uses the API. Even worse an empty string `""""` was allowed!

As it is, as far as I can tell, there is no way to create a field level validator that allows empty list and does not allow null. You could probably use a model level validator but that is non-ideal, and this feels like a potential way for bugs to emerge on a website.
"	Uncategorized	closed	Forms	3.1	Normal	invalid			Unreviewed	0	0	0	0	0	0