Criando um interceptor para tratamento de erros

src/app/app.module.ts

@@ -8,6 +8,7 @@ import { MyApp } from './app.component';
 import { StatusBar } from '@ionic-native/status-bar';
 import { SplashScreen } from '@ionic-native/splash-screen';
 import { CategoriaService } from '../services/domain/categoria.service';
+import { ErrorInterceptorProvider } from '../interceptors/error-interceptor';
 
 @NgModule({
   declarations: [
@@ -26,7 +27,8 @@ import { CategoriaService } from '../services/domain/categoria.service';
     StatusBar,
     SplashScreen,
     {provide: ErrorHandler, useClass: IonicErrorHandler},
-    CategoriaService
+    CategoriaService,
+    ErrorInterceptorProvider
   ]
 })
 export class AppModule {}

src/interceptors/error-interceptor.ts

@@ -0,0 +1,32 @@
+import { Injectable } from '@angular/core';
+import { HttpEvent, HttpInterceptor, HttpHandler, HttpRequest, HTTP_INTERCEPTORS } from '@angular/common/http';
+import { Observable } from 'rxjs/Rx'; // IMPORTANTE: IMPORT ATUALIZADO
+@Injectable()
+export class ErrorInterceptor implements HttpInterceptor {
+
+    intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
+        console.log("Passou no interceptor");
+        return next.handle(req)
+        .catch((error, caught) => {
+
+            let errorObj = error;
+            if (errorObj.error) {
+                errorObj = errorObj.error;
+            }
+            if (!errorObj.status) {
+                errorObj = JSON.parse(errorObj);
+            }
+
+            console.log("Erro detectado pelo interceptor:");
+            console.log(errorObj);
+
+            return Observable.throw(errorObj);
+        }) as any;
+    }
+}
+
+export const ErrorInterceptorProvider = {
+    provide: HTTP_INTERCEPTORS,
+    useClass: ErrorInterceptor,
+    multi: true,
+};

src/pages/categorias/categorias.ts

@@ -34,9 +34,7 @@ export class CategoriasPage {
       .subscribe(response => {
         this.items = response;
       },
-        error => {
-          console.log(error);
-        });
+        error => {});
   }
 
 }