Default dict value in JSONField causes non-valid JSON string stored in db.

I have a model with JSONField with default value set to constant dict value.

The default value was stored in db as non-valid json.

I was able to work around this by changing this line (in my model): visual_config = JSONField(default=DEFAULT_PARAMETERS['visual_config'], blank=False, null=False) With this: visual_config = JSONField(default=lambda: CustomerConfig.DEFAULT_PARAMETERS['visual_config'], blank=False, null=False)

Notice that I added default value as lambda function.

This is caused by django default Field.get_default method, which runs force_text method on the default value if it is not callable:

def get_default(self):
        """
        Returns the default value for this field.
        """
        if self.has_default():
            if callable(self.default):
                return self.default()
            return force_text(self.default, strings_only=True)
        if (not self.empty_strings_allowed or (self.null and
                   not connection.features.interprets_empty_strings_as_nulls)):
            return None
        return ""

My idea for a fix would be to override the get_default method in JSONField.

Cheers, Maciej

[ketanbhatt]

I found a workaround. Doing a json.dumps gets rid of the issue.

My dict was like:

mydic = { "key": "value"}

I stored it as valid json by:

class NotificationTemplate(models.Model):
    extra = JSONField(default=json.dumps(NOTIFICATION_TEMPLATE_EXTRA)))

Remove the json.dumps it gets stored as:

{ 'key': 'value'}

which is invalid

[skorokithakis]

Fixed in 6912356, as @nebril suggested. Thank you all for the report!