RXJS: How to get connect event? retrywhen: how to hook into execution?

Question

When Angular tries to connect, I want to show "Connecting". I can do it on first connect, but I don't know how to do it when using retryWhen(). I need to hook into the actual execution and then do:

this.connectionStatus = "Connecting"

Current code:

    this.connectionStatus = "Connecting";

    let socket = new WebSocketSubject(..);

    this.socket
      .pipe(retryWhen(errors =>
        errors.pipe(
          tap(val => {
            console.log("Retry in 10 sec", val);
          }),
          delay(10000)
        )))
      .subscribe(..);

The method gets called instantly but the reconnect is in 10 seconds. I want to set status to "connecting" when it is really connecting, not in advance. — NoobieNoob, Dec 14 '19 at 09:42

Fan Cheung · Accepted Answer · 2019-12-16T03:58:27.573

0

Just set the status after delay. retryWhen expect you to return an observable and when this observable emits it'll start retrying connecting i.e start retrying after delay

  errors.pipe(
          tap(val => {
            console.log("Retry in 10 sec", val);
          }),
          delay(10000),
          tap(()=>this.connectionStatus = "Connecting"
)
        )))

edited Dec 16 '19 at 03:58

answered Dec 14 '19 at 09:53

Fan Cheung

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Thanks. I dont know why it works that way, but it works. If you have time, please add an explanation. – NoobieNoob Dec 14 '19 at 22:52

RXJS: How to get connect event? retrywhen: how to hook into execution?

1 Answers1