mirror of
https://github.com/django/daphne.git
synced 2025-04-25 03:03:47 +03:00
95 lines
2.7 KiB
Python
95 lines
2.7 KiB
Python
import json
|
|
|
|
from django.core import serializers
|
|
|
|
from .base import Binding
|
|
from ..generic.websockets import WebsocketDemultiplexer
|
|
|
|
|
|
class WebsocketBinding(Binding):
|
|
"""
|
|
Websocket-specific outgoing binding subclass that uses JSON encoding
|
|
and the built-in JSON/WebSocket multiplexer.
|
|
|
|
To implement outbound, implement:
|
|
- group_names, which returns a list of group names to send to
|
|
|
|
To implement inbound, implement:
|
|
- has_permission, which says if the user can do the action on an instance
|
|
|
|
Optionally also implement:
|
|
- serialize_data, which returns JSON-safe data from a model instance
|
|
- create, which takes incoming data and makes a model instance
|
|
- update, which takes incoming data and a model instance and applies one to the other
|
|
"""
|
|
|
|
# Mark as abstract
|
|
|
|
model = None
|
|
|
|
# Stream multiplexing name
|
|
|
|
stream = None
|
|
|
|
# Outbound
|
|
@classmethod
|
|
def encode(cls, stream, payload):
|
|
return WebsocketDemultiplexer.encode(stream, payload)
|
|
|
|
def serialize(self, instance, action):
|
|
payload = {
|
|
"action": action,
|
|
"pk": instance.pk,
|
|
"data": self.serialize_data(instance),
|
|
"model": self.model_label,
|
|
}
|
|
return payload
|
|
|
|
def serialize_data(self, instance):
|
|
"""
|
|
Serializes model data into JSON-compatible types.
|
|
"""
|
|
if self.fields == ['__all__']:
|
|
fields = None
|
|
else:
|
|
fields = self.fields
|
|
data = serializers.serialize('json', [instance], fields=fields)
|
|
return json.loads(data)[0]['fields']
|
|
|
|
# Inbound
|
|
|
|
def deserialize(self, message):
|
|
"""
|
|
You must hook this up behind a Deserializer, so we expect the JSON
|
|
already dealt with.
|
|
"""
|
|
action = message['action']
|
|
pk = message.get('pk', None)
|
|
data = message.get('data', None)
|
|
return action, pk, data
|
|
|
|
def _hydrate(self, pk, data):
|
|
"""
|
|
Given a raw "data" section of an incoming message, returns a
|
|
DeserializedObject.
|
|
"""
|
|
s_data = [
|
|
{
|
|
"pk": pk,
|
|
"model": self.model_label,
|
|
"fields": data,
|
|
}
|
|
]
|
|
# TODO: Avoid the JSON roundtrip by using encoder directly?
|
|
return list(serializers.deserialize("json", json.dumps(s_data)))[0]
|
|
|
|
def create(self, data):
|
|
self._hydrate(None, data).save()
|
|
|
|
def update(self, pk, data):
|
|
instance = self.model.objects.get(pk=pk)
|
|
hydrated = self._hydrate(pk, data)
|
|
for name in data.keys():
|
|
setattr(instance, name, getattr(hydrated.object, name))
|
|
instance.save()
|