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
35885	JSONField does accept strings that look like dicts and incorrectly saves them as strings, breaking JSON filtering	DataGreed		"Steps to reproduce:

1. Create a model with JSONField, create a migration and migrate
2. Create an instance of this model, set the value of JSON field to a string generated by `json.dumps()` from any dictionary, e.g. ""{""foo"":""bar""}
3. Save the model instance
4. Instance save successfully

Expected result:

Instance is saved with the JSONField set to a dictionary {""foo"": ""bar""}, and JSONField deep filtering works properly

Actual result:

Instance is saved with a JSONField value saved as a string. Filtering does not work, and when you query this instance from a database, the JSONField value will be a string, not a dict.

I tried it on PostgreSQL and sqlite - both working incorrectly. 
Note that if I set JSONField value to an actual dict it works correctly, but it is too easy to make a mistake and then waste hours of debugging the reasons the JSON filtering does not work, since developers usually sanitize the data at least by dumping the dict to json to make sure it is even possible to dump. 

It seems like the fix would be to parse the string value in JSONField before saving.
My current workaround is to do the following on my models with JSONFields:



{{{
class SomeModel(models.Model):

    json_field = models.JSONField(blank=True, null=True)

    def clean(self):
        try:
            if isinstance(self.json_field, str):
                # make sure we are not trying to save string to JSONField, django allows this for some reason
                # and it breaks filtering on json
                self.arguments = json.loads(self.json_field)
        except ValueError as e:
            # reraise as validation error. We do this to get more actionable description for the error
            raise ValidationError(str(e))

    def save(self, *args, **kwargs):

        # ensure clean runs. Well, kind of - we can still directly update the fields,
        # and it will somewhat break data integrity, so just don't do that maybe? thanks :)
        self.full_clean()
        super().save(*args, **kwargs)
}}}
"	Uncategorized	closed	Database layer (models, ORM)	5.0	Normal	invalid		DataGreed	Unreviewed	0	0	0	0	0	0