How to use async subject in angular2?

Question

Hi i have a simple component and a service.When user clicks on submit button i am calling a service where an async subject emits a value to all its subscribers.I have done it using subject it works fine but i want to do it using Async Subject.I have made a demo here http://plnkr.co/edit/tHjPVZ5NurJRWdCM9lbt?p=preview ...This is my Service...

export class ErrorService{
  latestError:AsyncSubject<>=new AsyncSubject();

  error(){
    this.latestError.next('form submitted');
  }
}

And this is my component class where i am subscribing the asyncsubject

export class AppComponent { 
  result:any;
  constructor(private service:ErrorService){
    this.service.latestError.subscribe(err=> this.result=err);
  }

  onSubmit() { 
    this.service.error();
  }
}

But this is throwing error...I dont know where i am doing wrong...Somebody please help me to rectify this error and show me how to use async subject and emit values to its subscribers

Thierry Templier · Accepted Answer · 2016-04-04 06:20:05Z

4

You need to include the class this way:

import {AsyncSubject} from 'rxjs/subject/AsyncSubject';

@Injectable()
export class ErrorService{
  latestError:AsyncSubject<>=new AsyncSubject();
  error(){
    this.latestError.next('form submitted');
  }
}

See this plunkr: http://plnkr.co/edit/SAl4YVXKRWpS7OeTYMrd?p=preview.

edited Apr 4, 2016 at 6:20

answered Apr 4, 2016 at 5:56

Thierry Templier

203k44 gold badges407 silver badges365 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Pardeep Jain Over a year ago

is this import {AsyncSubject} from 'rxjs/subject/AsyncSubject'; any predefined class/import ?

abhilash reddy Over a year ago

But when .next() is called in my service class it emits a value.And i have subscribed the async subject in my constructor...But i am not getting the value which has been emitted by the async subject

Thierry Templier Over a year ago

@PardeepJain You can also import it from the rxjs/Rx module: import {AsyncSubject} from 'rxjs/Rx';.

Thierry Templier Over a year ago

@abhilashreddy you need to also call the complete method on the subject to receive your events. I updated my plunkr... plnkr.co/edit/SAl4YVXKRWpS7OeTYMrd?p=preview

Collectives™ on Stack Overflow

How to use async subject in angular2?

1 Answer 1

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related