drf-keyed-list-bihealth

Keyed Lists for Django REST Framework

This package supports the serialization and deserialization of a list of objects stored in a dict where a unique value from the object (often a pk) is used as the key in the dict. For example,

{
    "1": {
        <other fields for object with id 1> 
    },
    "2": {
        <other fields for object with id 2>
    },
    ...
}

Install

pip install drf-keyed-list

Usage

The following is a usage example:

from drf_keyed_list import KeyedListSerializer

class MySerializer(ModelSerializer):

    class Meta:
        list_serializer_class = KeyedListSerializer
        keyed_list_serializer_field = 'id'

By replacing the list_serializer_class, this behavior will only be enabled when the many=True flag is used:

instance = {
   "id": "pk_val",
   "field1": "val1",
   "field2": "val2",
   # ...
}

serializer = MySerializer(data=instance)
# this should work
serializer.is_valid()
serializer.save()

keyed_list = {
   "pk_val": {
       "field1": "val1",
       "field2": "val2",
       # ...
   }
}

# many=True will trigger the keyed-list behavior
serializer = MySerializer(data=keyed_list, many=True)
# this should also work
serializer.is_valid()
serializer.save()

NOTE: keyed_list_serializer_field MUST refer to a Unique field or key collision may occur during serialization, plus undefined deserializaiton behavior if used in combination with nested writable serializers (e.g. drf-writable-nested). At this time, the package does not make any effort to verify that a Unique field has been selected.

Non-String Keys (e.g. UUIDs)

Per the JSON RFC the keys (a.k.a. "names") in a JSON structure must be strings. The JSON Encoder in Py2 only accepts strings; in Py3, the encoder accepts some additional types (i.e. int, float, bool or None), but these must eventually be converted to strings. Other types are not supported, including common key types like UUID.

Per the discussion in issue #6, the recommended strategy for non-string keys is to use an expicit (if necessary, custom) serializer field. This field should implement to_representation and to_internal_value to convert the data to a string. For a UUID, the built-in UUIDField is sufficient.

Authors

2018, Clayton Daley III