Bug: serializing/deserializing of JSONfields fails

Dear developers,

JSON de-serialization fails with the following Error:

python data_grpc_client.py Traceback (most recent call last): File "/my_data/data_grpc_client.py", line 8, in for datum in stub.List(my_data.lara_data_pb2.DataListRequest()): File ".../python3.9/site-packages/grpc/_channel.py", line 426, in next return self._next() File .../lib/python3.9/site-packages/grpc/_channel.py", line 826, in _next raise self grpc._channel._MultiThreadedRendezvous: <_MultiThreadedRendezvous of RPC that terminated with: status = StatusCode.UNKNOWN details = "Exception iterating responses: Failed to parse data_JSON field: expected string or bytes-like object." debug_error_string = "{"created":"@1648155177.535827174","description":"Error received from peer ipv6:[::1]:50051","file":"src/core/lib/surface/call.cc","file_line":905,"grpc_message":"Exception iterating responses: Failed to parse data_JSON field: expected string or bytes-like object.","grpc_status":2}"

What is missing to support JSONField serialization / deserialization ?

To reproduce the Error:

I have a django (4.0.3) model with a JSON field:

# models.py

class Data(models.Model):
  data_id = models.AutoField(primary_key=True)
  data_JSON = models.JSONField(blank=True, null=True, help_text="JSON representation of the data")

My serializer.py looks like this:

from  my_data.models import Data
from django_grpc_framework import proto_serializers
from rest_framework import serializers
import my_data.my_data_pb2

class DataProtoSerializer(proto_serializers.ModelProtoSerializer):
    class Meta:
        model = Data
        proto_class = my_data.lara_data_pb2.Data
        fields = ['data_id', 'data_JSON']

The auto generated protofile file (I used the django framework proto generator) my_data.proto:


syntax = "proto3";

package my_data;

import "google/protobuf/empty.proto";

service DataController {
    rpc List(DataListRequest) returns (stream Data) {}
    rpc Create(Data) returns (Data) {}
    rpc Retrieve(DataRetrieveRequest) returns (Data) {}
    rpc Update(Data) returns (Data) {}
    rpc Destroy(Data) returns (google.protobuf.Empty) {}
}

message Data {
    int32 data_id = 1;
    string data_JSON = 2;
}

message DataListRequest {
}

message DataRetrieveRequest {
    int32 data_id = 1;
}

My service description - services.py :


from my_data.models import Data
from django_grpc_framework import generics
from my_data.serializers import DataProtoSerializer

class DataService(generics.ModelService):
    """
    gRPC service that allows users to be retrieved or updated.
    """
    queryset = Data.objects.all().order_by('data_id') 
    serializer_class = DataProtoSerializer

And finally the client: data_grpc_client.py:


import grpc
import my_data.my_data_pb2
import my_data.my_data_pb2_grpc

with grpc.insecure_channel('localhost:50051') as channel:
    stub = my_data.my_data_pb2_grpc.DataControllerStub(channel)
    for datum in stub.List(my_data.my_data_pb2.DataRequest()):
        print("datum:",datum.name, end='')

fengsp / django-grpc-framework

Bug: serializing/deserializing of JSONfields fails #35