i’m learning Angular and i have small problem with display responded data after HTTP get.

I’, requesting:

  private url = 'http://localhost:8070/app';
  private descriptors = '/myapp/test';

    constructor(private http: HttpClient) {
    }

    getDescriptors(): Observable<Descriptor[]> {

    let params = new HttpParams().set('methodType', 'firstVar').set('provider', 'secondVar');

    return this.http
      .get<Descriptor[]>(this.url + this.descriptors, {params})
      .pipe(tap(console.log));
  }

Additionally, i have component

  response: any;

  getDescriptors(){
    this.response = this.http.getDescriptors().subscribe();
  }

Descriptor[] is only:

  export interface Descriptor {
     values: string;
  }

And the HTML file:

{{ response | json}}

and i have response:

{ "closed": true, "_parentage": null, "_finalizers": null, "isStopped": true, "destination": null }

and error in console:

ERROR TypeError: Converting circular structure to JSON
--> starting at object with constructor 'SafeSubscriber'
|     property '_finalizers' -> object with constructor 'Array'
|     index 0 -> object with constructor 'OperatorSubscriber'
--- property '_parentage' closes the circle
at JSON.stringify (<anonymous>)
at JsonPipe.transform (common.mjs:4540:21)
at Module.ɵɵpipeBind1 (core.mjs:20893:22)
at AppComponent_Template (app.component.html:3:1)
at executeTemplate (core.mjs:10534:9)
at refreshView (core.mjs:10419:13)
at refreshComponent (core.mjs:11480:13)
at refreshChildComponents (core.mjs:10210:9)
at refreshView (core.mjs:10469:13)
at detectChangesInternal (core.mjs:11624:9)

In console I see that I’ve received correct JSON:

{values: {…}}
values  :   inputParameters :  (2) [{…}, {…}]
location : "Country"
methodType : "Method"
....
....
and so on...

Could you please help me how to get the body answer from request? I see that it is not so obvious like in general JS.

Thanks

>Solution :

To get the response data, you need to provide a callback function to the subscribe() method. This function will be called with the response data when it’s available.

See below an example of how you could the body response.

getDescriptors() {
  this.http.getDescriptors().subscribe(
    (data) => {
      this.response = data;
      console.log(this.response); // just to make sure it works
    },
    (error) => {
      console.error(error);
    }
  );
}

In this code, the getDescriptors() method now calls subscribe() with two callback functions: one for handling the response data ((data) => { … }) and one for handling errors ((error) => { … }). When the response data is received, the data argument contains the parsed JSON object. You can assign it to the response property to display it in the template.