Subscriptions support

[mysterioushunt]

Support GraphQL subscriptions or is there a way to use apollographql/graphql-subscriptions and apollographql/subscriptions-transport-ws with express-graphql?

[perrosnk]

+1

[bwoodlt]

+1

[gauravmakkar]

+1

[junminstorage]

subscriptions-transport-ws should create a websocket server. And I figured it out like below by adding subscription operation support in express-graphql's graphiql explorer.

const { execute, subscribe } = require('graphql');
const {createServer} = require('http');
const  { SubscriptionServer } = require('subscriptions-transport-ws');

const PORT = 4000;
const subscriptionsEndpoint = `ws://localhost:${PORT}/subscriptions`;

var app = express();
app.use('/graphql',  graphqlHTTP({
    schema: schema,
    graphiql: true,
    subscriptionsEndpoint: subscriptionsEndpoint
}));

// Create listener server by wrapping express app
const webServer = createServer(app);

webServer.listen(PORT, () => {
    console.log(`GraphQL is now running on http://localhost:${PORT}`);

    // Set up the WebSocket for handling GraphQL subscriptions.
    new SubscriptionServer({
        execute,
        subscribe,
        schema
    }, {
        server: webServer,
        path: '/subscriptions',
    });

});

Let me know if this solves the issue and I can create a PR.

[calvernaz]

@junminstorage this didn't work out for me. I had to plug the module graphql-playground-middleware-express to make it work, but I'm still investing what's the issue tho, given that I'm not sure if the problem is with GraphiQL not triggering the connection.

[junminstorage]

@calvernaz thanks for bringing this up. conjunction with above I will need make a PR to expresss-graphql to make it work.
Let me create PR today.

[junminstorage]

PR: #436
@calvernaz let me know if it works for you.

[calvernaz]

Sure @junminstorage, is the fix pinned to any specific version?

[junminstorage]

I merged the current master to my PR branch. Actually it should work for last release as well which I tested. But if you can help me try it out with latest release and confirm, then we have good confidence to ask @IvanGoncharov to approve it.

[calvernaz]

The last version still doesn't work, and it makes sense for me given that commit is not merged yet.

Maybe it worked for you because was cached or you missed to delete your local copy?

I tried to point my dependency to your repository but without success, not sure why npm refuses to pull the code from there.

[junminstorage]

Right, the PR is not merged yet and not in any releases. I was meaning the changes in the PR should work for any release greater than v0.6.12 and master too.

For your local test, you need to remove the existing express-graphql in the node_modules/ folder under the nodejs project you are working on, then git clone https://github.com/junminstorage/express-graphql/ , and checkout branch named 'subscription-graphiql-support', then do npm link install this specific project, see doc here: https://docs.npmjs.com/cli/link

Let me know if you still have any problems after doing this.

I am planning to build a sample project here: https://github.com/junminstorage/graphql-sample, so you may be able to check it out and run it to see how it works. But it will take me some time to do it.

[calvernaz]

Good news, it worked!! I had to build the dependency first to create the dist folder where the package.json points to the main file, but worked as shown in the image

[junminstorage]

Yep, the source code is typescript. And that is awesome! Thank you!

@IvanGoncharov can you comment on the PR #436 and so we can move forward on this?