CODEWITHSUNDEEP
angularrxjsrxjs5
POV
POV

Reputation: 12005

How to get result of Observer in subscribe?

I have two Observable requests to server:

this.initService.__init__(res).subscribe((profile) => {
    console.log(profile); // It works
    this.initService.initializePeriod(profile).subscribe((period) => {
        console.log(period); // It does not work
    });

});

When first gets response it calls second, but I can not get result for second subscribe. I know, better to use Promises in this case, but I need pass result from first request to second, promises dont allow to do this.

I tried to use this, but Alert message does not work:

 this.initService.__init__(res)
            .pipe(
              mergeMap(profile => this.initService.initializePeriod(profile)))
              .subscribe((response) => {
              alert('aa');

});

Also tried this:

this.initService.__init__(res)
              .mergeMap(profile => this.initService.initializePeriod(profile))
              .subscribe((response) => {
              alert('aa');
});

Upvotes: 1

Views: 1132

Answers (2)

Sachin Gupta
Sachin Gupta

Reputation: 5301

You need to check the result that you are getting from your first API call (profile). Check your browser console. Chances are that the profile is probably a JSON, not a valid URL. The request will not go through if the URL is not valid.

If you provide a valid URL, API call inside another API call should work.

Upvotes: 0

Sunil
Sunil

Reputation: 11243

You can use switchMap rxjs operators to chain the observables.

import { switchMap } from 'rxjs/operators';

this.initService.__init__(res)
.pipe(
   switchMap(profile=> this.initService.initializePeriod(profile))
).subscribe((period) => {
    console.log(period);
});

If you want to have response from both then use mergeMap

import { mergeMap } from 'rxjs/operators';

this.initService.__init__(res)
.pipe(
   mergeMap(
      profile=> this.initService.initializePeriod(profile), 
     (profile, period) => {
       return [profile,period];
}
   )
).subscribe((response) => {
    console.log(response[0]); //profile
    console.log(response[1]); //period
});

Working copy is here - https://stackblitz.com/edit/typescript-wy26a7

Upvotes: 2

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