Fixed RelatedField(required=False) bug

[nazarewk]

Description

I encountered the issue in totally unrelated (and invalid according to docs) case, but also found valid use case where it fails in exactly the same way.

When we want to fill-in the field specifically on Model level instead of ModelSerializer we would make it required=False, allow_empty=True and not pass the field at all in data.

Before this fix resolution of Serializer.data would yield KeyError.

[tomchristie]

When we want to fill-in the field specifically on Model level instead of ModelSerializer

For this case you should make the field read_only=True on the serializer.

[cgthayer]

@tomchristie if you do read_only=True then you can't pass it in if you wish to, right? For "required=False" I'd expect I could omit the key and value from data, or include it.

[mazharrazmian]

I still get the error. I have an AssetSerializer and a PriaryKeyRelatedField with required=false in it, named 'asset_devices'. When i don't provide devices data, it gives me key error.

If this has been fixed, and I am using the latest version of DRF, why am I still getting this error?