graphql-ws-subs 0.0.2

Websocket server for GraphQL subscriptions that includes subscriptions implementation from hballard

GraphQL WS

Websocket server for GraphQL subscriptions.

Currently supports:

• aiohttp

• Gevent

• Sanic (uses websockets library)

Installation instructions

For instaling graphql-ws, just run this command in your shell

pip install graphql-ws

Examples

aiohttp

For setting up, just plug into your aiohttp server.

from graphql_ws.aiohttp import AiohttpSubscriptionServer


subscription_server = AiohttpSubscriptionServer(schema)

async def subscriptions(request):
    ws = web.WebSocketResponse(protocols=('graphql-ws',))
    await ws.prepare(request)

    await subscription_server.handle(ws)
    return ws


app = web.Application()
app.router.add_get('/subscriptions', subscriptions)

web.run_app(app, port=8000)

Sanic

Works with any framework that uses the websockets library for it’s websocket implementation. For this example, plug in your Sanic server.

from graphql_ws.websockets_lib import WsLibSubscriptionServer


app = Sanic(__name__)

subscription_server = WsLibSubscriptionServer(schema)

@app.websocket('/subscriptions', subprotocols=['graphql-ws'])
async def subscriptions(request, ws):
    await subscription_server.handle(ws)
    return ws


app.run(host="0.0.0.0", port=8000)

And then, plug into a subscribable schema:

import asyncio
import graphene


class Query(graphene.ObjectType):
    base = graphene.String()


class Subscription(graphene.ObjectType):
    count_seconds = graphene.Float(up_to=graphene.Int())

    async def resolve_count_seconds(root, info, up_to):
        for i in range(up_to):
            yield i
            await asyncio.sleep(1.)
        yield up_to


schema = graphene.Schema(query=Query, subscription=Subscription)

You can see a full example here: https://github.com/graphql-python/graphql-ws/tree/master/examples/aiohttp

Gevent

For setting up, just plug into your Gevent server.

subscription_server = GeventSubscriptionServer(schema)
app.app_protocol = lambda environ_path_info: 'graphql-ws'

@sockets.route('/subscriptions')
def echo_socket(ws):
    subscription_server.handle(ws)
    return []

And then, plug into a subscribable schema:

import graphene
from rx import Observable


class Query(graphene.ObjectType):
    base = graphene.String()


class Subscription(graphene.ObjectType):
    count_seconds = graphene.Float(up_to=graphene.Int())

    async def resolve_count_seconds(root, info, up_to=5):
        return Observable.interval(1000)\
                         .map(lambda i: "{0}".format(i))\
                         .take_while(lambda i: int(i) <= up_to)


schema = graphene.Schema(query=Query, subscription=Subscription)

You can see a full example here: https://github.com/graphql-python/graphql-ws/tree/master/examples/flask_gevent

Django Channels

First pip install channels and it to your django apps

Then add the following to your settings.py

CHANNELS_WS_PROTOCOLS = ["graphql-ws", ]
CHANNEL_LAYERS = {
    "default": {
        "BACKEND": "asgiref.inmemory.ChannelLayer",
        "ROUTING": "django_subscriptions.urls.channel_routing",
    },

}

Setup your graphql schema

import graphene
from rx import Observable


class Query(graphene.ObjectType):
    hello = graphene.String()

    def resolve_hello(self, info, **kwargs):
        return 'world'

class Subscription(graphene.ObjectType):

    count_seconds = graphene.Int(up_to=graphene.Int())


    def resolve_count_seconds(
        root,
        info,
        up_to=5
    ):
        return Observable.interval(1000)\
                            .map(lambda i: "{0}".format(i))\
                            .take_while(lambda i: int(i) <= up_to)



schema = graphene.Schema(
    query=Query,
    subscription=Subscription
)

Setup your schema in settings.py

GRAPHENE = {
    'SCHEMA': 'path.to.schema'
}

and finally add the channel routes

from channels.routing import route_class
from graphql_ws.django_channels import GraphQLSubscriptionConsumer

channel_routing = [
    route_class(GraphQLSubscriptionConsumer, path=r"^/subscriptions"),
]