How to modify response using Interception?

Question

I use the following interception in Angular:

return next.handle(request).pipe(
      map((event: any) => {
        if (event.body.data) {
          return event.body.data;
        }
      }));

My JSON response contains data property. So I try to return it: return event.body.data;.

My service is:

public get(): Observable<any> {
   return this.http.get(environment.serverUrl + 'events');
}

Using service:

this.serviceEbents.get().subscribe(response => {
     console.log(response);
});

Problem is:

ERROR TypeError: Cannot read property 'data' of undefined
    at MapSubscriber.project (RequestInterception.ts:43)
    at MapSubscriber.push../node_modules/rxjs/_esm5/internal/operators/map.js.MapSubscriber._next

Therefore I dont get console.log(response);.

Interception doesn't make sense unless *all* of your responses will have those properties. Also note that `Observable` isn't a very helpful signature for the consumers! — jonrsharpe, Mar 01 '19 at 16:10

score 1 · Accepted Answer · answered Mar 01 '19 at 16:19

1

The HttpClient already returns just body of the response, if you want to receive the full response, and thereby necessitate getting the body using response.body then you need to 'observe the response' described here https://angular.io/guide/http#reading-the-full-response

your service would look like

public get(): Observable<any> {
   return this.http.get(environment.serverUrl + 'events', { observe: 'response' });
}

otherwise just say return event

also you should console.log the event to debug this issue.

answered Mar 01 '19 at 16:19

Joey Gough

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I want to get only body and reduce body by property `data`. data: [] to get simple: [] – POV Mar 01 '19 at 16:21
So, that why I try to use map in interceptions to reduce by `data` – POV Mar 01 '19 at 16:25

How to modify response using Interception?

1 Answers1