How to create a model with foreign keys with SwampDragon?

Question

I'm creating a chat demo using SwampDragon and I'm unsure how to create a model with related fields.

Using the code below, an error occurs each time I call the createMessage function in javascript. The only error I receive is from the websocket output: c[3001,"Connection aborted"]. There is no output on the python console to shed any extra light on this error.

Can anyone help me understand how to create a Message, with the related field of User?

Model:

from django.contrib.auth.models import User
from django.db import models

from swampdragon.models import SelfPublishModel

from .serializers import MessageSerializer


class Message(SelfPublishModel, models.Model):
    serializer_class = MessageSerializer

    user = models.ForeignKey(User, related_name='messages')
    body = models.TextField(blank=True)

Serializer:

from swampdragon.serializers.model_serializer import ModelSerializer
from django.contrib.auth.models import User


class UserSerializer(ModelSerializer):

    class Meta:
        model = User
        publish_fields = ('id', 'username')
        update_fields = ('first_name', 'last_name', )


class MessageSerializer(ModelSerializer):
    user = UserSerializer

    class Meta:
        model = b'chat.Message'
        publish_fields = ('body', 'user', )
        update_fields = ('body', 'user', )

Route:

from swampdragon import route_handler
from swampdragon.route_handler import ModelRouter, BaseRouter

from .models import Message
from .serializers import MessageSerializer, UserSerializer


class MessageRouter(ModelRouter):
    route_name = 'message'
    serializer_class = MessageSerializer
    model = Message
    include_related = [UserSerializer, ]

    def get_object(self, **kwargs):
        return self.model.objects.get(pk=kwargs['id'])

    def get_query_set(self, **kwargs):
        return self.model.objects.all()

route_handler.register(MessageRouter)

Javascipt:

...
  createMessage: function(message){
    var data = {
      user: 1,
      body: message
    };
    swampdragon.create('message', data, function (context, data) {
       console.log('MessageStore: onCreate success.', context, data);
    }, function (context, data) {
      console.log('MessageStore: onCreate failed.', context, data);
    });
  },
...

Requirements

• django==1.7.6
• SwampDragon==0.4.1.2
• SwampDragon-auth==0.1.3

Answer 1

To answer my own question: This is not built into the framework as I expected. You need to instantiate the related models in the router in the get_initial method. These will then be passed to the serializer and will create the Message model correctly.

Route

class MessageRouter(ModelRouter):
    route_name = 'message'
    serializer_class = MessageSerializer
    model = Message
    include_related = [UserSerializer, ]

    def get_initial(self, verb, **kwargs):
        user = User.objects.get(pk=kwargs['user_id'])
        return {'user': user}

    def get_object(self, **kwargs):
        return self.model.objects.get(pk=kwargs['id'])

    def get_query_set(self, **kwargs):
        return self.model.objects.all()

Javascript

...
  createMessage: function(message){
    var data = {
      user_id: 1,
      body: message
    };
    swampdragon.create('message', data, function (context, data) {
       console.log('MessageStore: onCreate success.', context, data);
    }, function (context, data) {
      console.log('MessageStore: onCreate failed.', context, data);
    });
  },
...

Serializer

class MessageSerializer(ModelSerializer):
    user = UserSerializer

    class Meta:
        model = b'chat.Message'
        publish_fields = ('body', 'user', )
        update_fields = ('body', )