Bits of code

SubSink

RxJS subscription sink for unsubscribing gracefully in a component.

SubSink is a dead simple class to absorb RxJS subscriptions in an array.

Call unsubscribe() to unsubscribe all of them, as you would do in your component library's unmount/onDestroy lifecycle event.

Installation

npm install subsink --save

Angular examples

There are 2 main ways to use the SubSink: the "easy" way and the "add/array" way.

RxJS supports adding subscriptions to an array of subscriptions. You can then unsubscribe directly from that array. If this appeals to you, then feel free to use it. If you prefer the technique with SubSink using the setter (aka easy) syntax below, then use that. Either way, no judgments are made. This is entirely up to you to decide.

Easy Syntax

Example using the sink property to collect the subscriptions using a setter.

export class SomeComponent implements OnDestroy { 
 private subs = new SubSink();  
  ...  
  this.subs.sink = observable$.subscribe(...);  
  this.subs.sink = observable$.subscribe(...);  
  this.subs.sink = observable$.subscribe(...);  
  ...   
  // Unsubscribe when the component dies  
  ngOnDestroy() {    
  this.subs.unsubscribe();  
   }
  }

The Array/Add Technique

Example using the .add technique. This is similar to what RxJS supports out of the box.

export class SomeComponent implements OnDestroy {
  private subs = new SubSink();
     ...
        this.subs.add(observable$.subscribe(...));
        this.subs.add(observable$.subscribe(...));
// Add multiple subscriptions at the same time  
this.subs.add(     
       observable$.subscribe(...),
       anotherObservable$.subscribe(...)  
       );    
       ...   
// Unsubscribe when the component dies  
ngOnDestroy() {
    this.subs.unsubscribe();
      }}

Get results of chained observables in subscription

this.Service1 
    .getSomething() 
    .pipe( 
        switchMap(
            result1 => this.service2.getAnotherSomething()
                .pipe(map(result2 => ({ result1, result2 }))), 
                ),
         ) 
                .subscribe(results => {
                 console.log(results.result1,results.result2) 
                     })