Specifying required=False on a custom field

[Richard Hughes]

A String List Field declared outside of the Serializer Class with
required=False does not honor the required=False property when instantiated
in the Serializer Class. The 'field is required' error is returned.

The required=False has to be declared when the Field is being
instantiated. Is this a bug or expected behavior?

class StringListField(serializers.ListField):
child = serializers.CharField()


def to_representation(self, data):
return [x.name for x in data.all()]

class EngSerializer(serializers.ModelSerializer):


class Meta:
model = EngineeringFileModel
fields = '__all__'
depth = 2
read_only_fields = ('last_edited_date', 'base_name', 'file_type',
'size', 'date_added', 'mime')


grid_cells = StringListField(required=False)

[Jason]

If you look at the implementation for Field,
https://github.com/encode/django-rest-framework/blob/master/rest_framework/fields.py#L307-L316

you can see it is initialized with required = None, but its included as a
kwarg for overriding. Since required is not an instance or class
attribute, if you override it in a re-implementation, it won't have any
effect