Why is my ionic app giving me the error 'Cannot GET /' when I run it?

@mlandgrafstl wrote:

I am writing an application for a grocery list with Ionic, and I’m currently trying to integrate the information in mongoDB with my Ionic app. However, when I run ‘ionic serve’, the only thing that loads in the browser is ‘Cannot GET /’. I’m not sure where I’ve gone wrong in my code. Any help would be greatly appreciated! I’ve included the code for my ‘Groceries-Service’ service. When I compile, I get the error 'Type Observable<{}> is not assignable to type ‘Observable<object[ ]>’. I think the problem is in the getItems function.

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Observable } from 'rxjs/Observable';
import { map, catchError } from 'rxjs/operators';
import { Subject } from 'rxjs';

@Injectable({
  providedIn: 'root'
})
export class GroceriesServiceService {

  items: any = [];

  dataChanged$: Observable<boolean>;

  private dataChangeSubject: Subject<boolean>;

  baseURL = "http://localhost:8080";

  constructor(public http: HttpClient) {
    console.log('Hello GroceriesServiceProvider Provider');

    this.dataChangeSubject = new Subject<boolean>();
    this.dataChanged$ = this.dataChangeSubject.asObservable();
   }

  getItems(): Observable<object[]> {
    return this.http.get(this.baseURL + '/api/groceries').pipe(
      map(this.extractData),
      catchError(this.handleError)
      );
  }

  private extractData(res: Response) {
    let body = res;
    return body || {};
  }

  private handleError(error: Response | any) {
    let errMsg: string;
    if (error instanceof Response) {
      const err = error | '';
      errMsg = `${error.status} - ${error.statusText || ''} ${err}`;
    } else {
      errMsg = error.message ? error.message : error.toString();
    }
    console.error(errMsg);
    return Observable.throw(errMsg);
  }

  removeItem(id){
    console.log("#### Remove Item - id = ", id);
    this.http.delete(this.baseURL + "/api/groceries/" + id).subscribe(res => {
      this.items = res;
      this.dataChangeSubject.next(true);
    });
  }

  addItem(item){
    this.http.post(this.baseURL + "/api/groceries", item).subscribe(res => {
      this.items = res;
      this.dataChangeSubject.next(true);
    })
  }

  editItem(item, index) {
    console.log("Editing item = ", item);
    this.http.put(this.baseURL + "/api/groceries/" + item._id, item).subscribe(res => {
      this.items = res;
      this.dataChangeSubject.next(true);
      
    });
  }
}

Posts: 1

Participants: 1

Read full topic