how to keep only one parameter in a subject?

Question

from a controller I input a parameter to a subject

  selectImport(event){
      this.importacionService.onChildSelectImportChanged.next(event);
  }

and from my component importacion.component.ts I subscribe to this subject

this.importacionService.onSelectImportChanged.subscribe( addImport => {

    this.importacionService.addImport(this.month, addImport);
   });


  }

Now everything is fine but when I close the dialog of importacion.component.ts and I'll do it again, the subject creates a second suscbripcion and therefore 2 observers, then when I enter a new data with .next() the subscriber runs twice .

how can I control this behavior, my expected behavior is that only exist and parameter in my subject and only run when its value changes

You just need to unsubscribe when closing the dialog – Robin Dijkhof Dec 13 '17 at 13:41 — Robin Dijkhof, Dec 13 '17 at 13:41
I get an error with this message "object unsubscribed" – Luis Ruiz Figueroa Dec 13 '17 at 13:54 — Luis Ruiz Figueroa, Dec 13 '17 at 13:54

score 1 · Answer 1 · edited Dec 13 '17 at 15:46

1

Put this in your component

private subscription: Subscription;

ngOnInit() {
    this.subscription = this.importacionService.onSelectImportChanged.subscribe(...);
}

ngOnDestroy() {
    if (this.subscription){
        this.subscription.unsubscribe();
    }
}

You need to unsubscribe from observables you create or manage yourself

edited Dec 13 '17 at 15:46

bygrace

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answered Dec 13 '17 at 13:47

YourGoodFriend

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I tried it that way but when I open the dialog again it generates an error – Luis Ruiz Figueroa Dec 13 '17 at 13:50
Look at this: https://toddmotto.com/passing-data-angular-2-components-input try using inputs and outputs to pass data between components – YourGoodFriend Dec 13 '17 at 13:53
I get an error with this message "object unsubscribed" – Luis Ruiz Figueroa Dec 13 '17 at 13:55
For anyone else wondering how you get the "object unsubscribed" error: you get it by calling unsubscribe on a subject rather than the subscription returned from `.subscribe`. – bygrace Dec 13 '17 at 15:41
@LuisRuizFigueroa updated code example to unsub from subscription rather than subject. – bygrace Dec 13 '17 at 15:47

how to keep only one parameter in a subject?

1 Answers1