Django: Make a GET Request to a URL that is advanced - django

Question

So I have Chat Rooms and I have Messages. Then I have two urls: /messages and /rooms. And these display all your rooms and messages. Also a message can be assigned to a room. So in the Room API I have the messages assigned to that room.
Let's say that the room is called 'Room1' and the messages are 'hey', 'yo' and 'wassup'. If I make a request to just /messages I will get all of the messages. Let's say that only two of the messages are assigned to 'Room1' and the other message is assigned to another room not named.
I want a way to make a get request and only get those two messages assigned to 'Room1 with id = 3' (localhost:8000/rooms/3/messages) instead of: (localhost:8000/messages).
This is an example of when I make a get request to /rooms/3/
{
"id": 3,
"name": "Room 1",
"members": [
{
"id": 1,
"username": "william"
},
{
"id": 2,
"username": "eric"
},
{
"id": 3,
"username": "ryan"
}
],
"messages": [
{
"id": 7,
"content": "hej",
"date": "2019-07-08",
"sender": {
"id": 1,
"username": "william"
}
},
{
"id": 8,
"content": "yoyo",
"date": "2019-07-08",
"sender": {
"id": 2,
"username": "eric"
}
},
{
"id": 9,
"content": "tjo bror",
"date": "2019-07-08",
"sender": {
"id": 3,
"username": "ryan"
}
},
{
"id": 10,
"content": "hej jag heter Eric och jag gar pa polhemskolan i lund och jag ar 17 ar gammal",
"date": "2019-07-08",
"sender": {
"id": 2,
"username": "eric"
}
},
{
"id": 11,
"content": "vi vet hahah",
"date": "2019-07-09",
"sender": {
"id": 1,
"username": "william"
}
},
{
"id": 12,
"content": "amen sluta",
"date": "2019-07-09",
"sender": {
"id": 2,
"username": "eric"
}
}
]
}
This is what I want to get in response if I do rooms/3/messages:
"messages": [
{
"id": 7,
"content": "hej",
"date": "2019-07-08",
"sender": {
"id": 1,
"username": "william"
}
},
{
"id": 8,
"content": "yoyo",
"date": "2019-07-08",
"sender": {
"id": 2,
"username": "eric"
}
},
{
"id": 9,
"content": "tjo bror",
"date": "2019-07-08",
"sender": {
"id": 3,
"username": "ryan"
}
},
{
"id": 10,
"content": "hej jag heter Eric och jag gar pa polhemskolan i lund och jag ar 17 ar gammal",
"date": "2019-07-08",
"sender": {
"id": 2,
"username": "eric"
}
},
{
"id": 11,
"content": "vi vet hahah",
"date": "2019-07-09",
"sender": {
"id": 1,
"username": "william"
}
},
{
"id": 12,
"content": "amen sluta",
"date": "2019-07-09",
"sender": {
"id": 2,
"username": "eric"
}
}
]
}
Django Models:
class UserProfile(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
class Meta:
verbose_name_plural = 'All Users'
def __str__(self):
return self.user.username
#receiver(post_save, sender=User)
def create_user_data(sender, update_fields, created, instance, **kwargs):
if created:
user = instance
profile = UserProfile.objects.create(user=user)
class Message(models.Model):
sender = models.ForeignKey(UserProfile, on_delete=models.CASCADE, related_name="sendermessage")
content = models.CharField(max_length=500)
date = models.DateField(default=date.today)
canview = models.ManyToManyField(UserProfile, blank=True, related_name="messagecanview")
class Meta:
verbose_name_plural = 'Messages'
def __str__(self):
return "{sender}".format(sender=self.sender)
class Room(models.Model):
name = models.CharField(max_length=50)
members = models.ManyToManyField(UserProfile, blank=True)
messages = models.ManyToManyField(Message, blank=True)
class Meta:
verbose_name_plural = 'Rooms'
def __str__(self):
return "{name}".format(name=self.name)enter code here
Django Serializers:
class UserProfileSerializer(serializers.ModelSerializer):
username = serializers.CharField(source='user.username')
class Meta:
model = UserProfile
fields = ('id', 'username')
class MessageSerializer(serializers.ModelSerializer):
sender = UserProfileSerializer()
class Meta:
model = Message
fields = ('id', 'content', 'date', 'sender')
class RoomSerializer(serializers.ModelSerializer):
messages = MessageSerializer(many=True)
members = UserProfileSerializer(many=True)
class Meta:
model = Room
fields = ('id', 'name', 'members', 'messages')
Django Views:
class UserProfileView(viewsets.ModelViewSet):
http_method_names = ['get', 'post', 'put', 'delete', 'patch']
queryset = UserProfile.objects.all()
serializer_class = UserProfileSerializer
class MessageView(viewsets.ModelViewSet):
http_method_names = ['get', 'post', 'put', 'delete', 'patch']
queryset = Message.objects.all()
serializer_class = MessageSerializer
class UserMessageView(MessageView):
def get_queryset(self):
return Message.objects.filter(canview__user=self.request.user)
class RoomView(viewsets.ModelViewSet):
http_method_names = ['get', 'post', 'put', 'delete', 'patch']
queryset = Room.objects.all()
serializer_class = RoomSerializer
class UserRoomView(RoomView):
def get_queryset(self):
return Room.objects.filter(members__user=self.request.user)
Django Urls:
router = routers.DefaultRouter()
router.register('users', views.UserProfileView),
router.register('rooms', views.UserRoomView),
router.register('messages', views.UserMessageView),
urlpatterns = [
path('', include(router.urls)),
]

Answer 1

To get all Messages assigned to a room, let's:
Install django-filter:
pip install django-filter
Modify the Room model to specify a related_name:
class Room(models.Model):
name = models.CharField(max_length=50)
members = models.ManyToManyField(UserProfile, blank=True)
messages = models.ManyToManyField(Message, blank=True, related_name='rooms')
# ^^^^^^^^^^^^^^^^^^^^^^
Enable filtering for the rooms related field:
import django_filters
import rest_framework.filters
[...]
class MessageView(viewsets.ModelViewSet):
# vvvvvvvvvvv I don't think this line is needed vvvvvvvvvvvvvv
# http_method_names = ['get', 'post', 'put', 'delete', 'patch']
queryset = Message.objects.all()
serializer_class = MessageSerialize
filter_backends = (
django_filters.rest_framework.DjangoFilterBackend,
rest_framework.filters.OrderingFilter,
)
filter_fields = ['rooms']
Then, you can request all messages for that room with a GET to:
localhost:8000/messages/?rooms=3
Comment question:
You also need to expose the Message object's sender field. Currently it is aliased:
class MessageSerializer(serializers.ModelSerializer):
# vvvv vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
sender_obj = UserProfileSerializer(source='sender', read_only=True)
class Meta:
model = Message
fields = ('id', 'content', 'date', 'sender', 'sender_obj')
# ^^^^^^^^^^^^^^
Then you can POST to /message with the data {"content": "blah", "date": "2019-07-09","sender": 1}