I have a global HttpInterceptor with a catch block which handles an HttpErrorResponse. But my requirement is that when a service makes the http call and also has an error handler i want the error handler on the service to go off first. If there is no error handler on this service then i want the global HttpInterceptor error handler to handle it.
Example code:
Http Interceptor:
@Injectable()
export class ErrorHttpInterceptor implements HttpInterceptor {
constructor(private notificationService: NotificationService) {}
intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
return next.handle(req)
.catch(
error => {
if (error instanceof HttpErrorResponse) {
this.notificationService.error('Error', 'Error in handling Http request');
}
return Observable.empty<HttpEvent<any>>();
}
);
}
}
And the service call:
updateUser(id, data) {
return this.http
.patch(`${API.userUrl}/${id}`, {data: data})
.subscribe(
() => console.log('success'),
(err) => this.notificationService.error('custom code to handle this')
);
}
In this case the ErrorHttpInterceptor gives the notification and then the userService error handling also gives the error notification.
But In my usecase i want the ErrorHttpIntercetor to handle the error only if the underlying subscriptions didnt handle the error. Is there a way to do this?
One way to solve is to pass httpHeaders
with request:
request() {
const url = 'GoalTree/GetById/';
let headers = new HttpHeaders();
headers = headers.append('handleError', 'onService');
this.http.get(url, {headers: headers})
.pipe(
map((data: any) => {
this.showError = false;
}),
catchError(this.handleError)
)
.subscribe(data => {
console.log('data', data);
})
}
Interceptor.ts:
intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
this.spinnerService.show();
return next.handle(req).do(
(event: HttpEvent<any>) => {
if (event instanceof HttpResponse) {
this.spinnerService.hide();
}
},
(err: any) => {
if (req.headers.get('handleError') === 'onService') {
console.log('Interceptor does nothing...');
} else {
console.log('onInterceptor handle ', err);
}
}
);
}
and check request headers ininterceptor
's error callback.
But in this solution anywhere Interceptors handles request before the any service calls.