It is not possible to wait for subscription to subscribe

[aleksandrlat]

Intended outcome:
I want to implement response for mutation to come through websocket.
I.e.

• subscribe to subscription
• call mutation to trigger some long running process on server
• receive result of long running process in subscription message

But I can call mutation only after I can confirm I subscribed to subscription

Actual outcome:
loading is true when I subscribed to subscription

const { loading, data } = useSubscription(subscription)
// loading is true when I subscribed to it

How to reproduce the issue:
Just subscribe to subscription

Versions
version 3

[rossimelthomas]

any updates?

[phryneas]

I believe you can use the onData callback of useSubscription for this.

function MyComponent() {
  const calledRef = useRef(false);
  const { loading, data } = useSubscription(subscription, {
    onData({ data }) {
      if (!calledRef.current) {
        calledRef.current = true;

		console.log(data)
        // execute your mutation here
      }
    },
  });
}

I believe beyond that, we can't really do a lot here - React doesn't wait for something to happen before rendering, it just synchronously renders your component.

As a result I'm going to close this issue - if you have any further usage questions, please also consider joining our Discord - we try to keep the issue tracker for bug reports and usage questions more in the Discord.

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