Rxjs Observable doSomething onComplete
I Would Like to Use the Rxjs Observable. Basically It Works Fine, but I Need Not Just to React When Observer. Next() but Also When Observer. Complete() Is...
I would like to use the RXJS Observable. Basically it works fine, but I need not just to react when observer.next() but also when observer.complete() is called. How do I get the event of OnComplete of an RXJS Observable? In my opinion the RXJS doc is confusing.
export class Service {
myMethod():Observable<any> {
return Observable.create((observer:any) => {
for(let i=0; i<10; i++) {
observer.next(i);
}
if(true==true) {
// this event I need
observer.complete();
} else {
observer.error(xhr.response);
}
}
}
export class Component() {
// constructor etc.
doSome() {
this.service.myMethod()
// Here I would like to get OnComplete event
.catch(this.handleError)
.subscribe((num:any) => {
console.log(num);
});
}
}
2 Answers
The subscribe method accepts three callbacks. The last one is for the complete event.
doSome() {
this.service.myMethod()
.subscribe((num:any) => {
console.log(num);
}, (err) => {
this.handleError(err);
}, () => { // <----
this.handleComplete();
});
}
You could also leverage the finally operator for this.
doSome() {
this.service.myMethod()
.catch(this.handleError)
.finally(this.handleComplete) // <----
.subscribe((num:any) => {
console.log(num);
});
}
note:
there is a difference between the two examples in case we have errors:
if we would add console.logs we would see that in the first case
only handleError is printed
-> handleError
in the second case
-> handleError
-> finally
in other words finally is always called, were complete is not.
Elena Rostova holds a Master's degree in Public Health Journalism. She covers groundbreaking medical research, holistic wellness trends, mental health awareness, and nutritional science.
