CODEWITHSUNDEEP
angularobservableangularfire2
Sam van beastlo
Sam van beastlo

Reputation: 849

Angularfire2 how to handle multiple Observables in angular4-5

What is the best way to get the data from multiple observables before executing a function

EXAMPLE:

provider.ts

obs1 = this.afDB.object(`app/radio`).snapshotChanges();
obs2 = this.afDB.object(`app/users`).snapshotChanges();
obs3 = this.afDB.object(`app/song`).snapshotChanges();

app.ts

doSomething(){

console.log('this is my', ${radio}, 'it plays on this date:' ,${date}, 'this song', ${song}`);

}

i place the subscribtions inside eachother.. it works but.. what is the right way of handling this async behaviour?

doSomething(){

provider.obs1.subscribe(val1 =>{
provider.obs2.subscribe(val2 =>{
provider.obs3.subscribe(val3 =>{

 console.log('this is my', ${val1.payload.val().radio}, 'it plays on this date:' ,${val2.payload.val().date}, 'this song', ${val3.payload.val().song}`);

});
});
});

    }

Upvotes: 0

Views: 48

Answers (1)

Ajantha Bandara
Ajantha Bandara

Reputation: 1531

use forkJoin operator.

doSomething(){
   Observable.forkJoin(
      provider.obs1,
      provider.obs2,
      provider.obs3
   ).subscribe(data => {
       console.log("values: ",data[0], data[1], data[2]) 
   }, err => {
       console.log("Handle error here");
   })
}

Upvotes: 1

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