Filter fields in embedded document

[mapeebles]

I think this is a feature request but is there a way to filter fields from embedded documents? Think of a base document (in mongodb) that looks like this in JSON:

[{
  "_id":  12,
  "name": "test 1",
  "embdded_doc": {
     "_id": 1237652,
     "other_info": "this and that",
     "color": "red"
  } 
}]

and you only want to output: _id, name, embedded_doc.color

We are trying to avoid having to serialize the entire embedded doc since it could a be large memory footprint, especially when we are returning a list of the parent objects.

Thanks

[dbrgn]

This is not currently supported. Why don't you simply create a serializer that only serializes some of the fields?

[mapeebles]

We were hoping not to have to create one for every API's different use cases. We have a lot of listing api's that only need a subset of the model and their child documents fields so we feel the right approach is to have a general purpose interface that can filter on the request thus no need extra development and testing on each model.

[dbrgn]

I see. This library is intentionally pretty simple, it just filters the fields of the top-level serializer.

If you want to apply filters to nested serializers, that'll become a bit more complicated. If someone would provide a clean pull request with this feature and good test coverage, I wouldn't say no, but I don't have the capacity to add that feature right now.

Maybe https://github.com/rsinger86/drf-flex-fields already does what you are looking for?

[mapeebles]

I had looked at that one, but they seem to acknowledge the existence of the child documents and allow for expansion but I didn't notice a good way to restrict the output, and it would be more complex if we have multiple child document in a parent document.

Thanks though, I appreciate you taking the time to review the request.

[dbrgn]

Maybe you can create a feature request against drf-flex-fields. They seem to aim for more flexibilit than I do :)

Otherwise, writing custom code for the specific filtering needs might be quite simple to implement.