How to create subject ( rx.js) with 2 parameters?

Question

I am using service with subject as communication service for components in my angular2 application.

Calling method:

this.notification.create('test');

Service:

export class NotificationService {
  private static notificationSource = new Subject<any>()

  notiCreated$ = NotificationService.notificationSource.asObservable();

  create(message) {
    NotificationService.notificationSource.next(message);
  }
}

Called function:

  this.subscription = notification.notiCreated$.subscribe(
    data => {
       console.log(data);
       this.createNotification(data, 'warning');
  });

But I want to pass 2 params. And I got errors.

How can i do it?

eko · Accepted Answer · 2016-11-25T12:53:39.863

22

Since the api for next is next(value: T): void, it can only take one parameter. Ref: http://reactivex.io/rxjs/class/es6/Subscriber.js~Subscriber.html

As a workaround you can group the messages inside an object:

this.notification.create({message1:'test', message2:'test2'});

and when you consume, just select the message you need:

 this.subscription = notification.notiCreated$.subscribe(
    data => {
       console.log(data.message1, data.message2);
       this.createNotification(data.message1, 'warning');
  });

edited Nov 25 '16 at 12:53

answered Nov 25 '16 at 12:38

eko

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Is it impossible to do it with 2 param? – John Doe Nov 25 '16 at 12:44
@MaxKarpovets No because the api for `next` is `next(value: T): void;` so it only takes 1 parameter. – eko Nov 25 '16 at 12:45
2

You really helps me. Thanks – John Doe Nov 25 '16 at 12:48

How to create subject ( rx.js) with 2 parameters?

1 Answers1