Angular 5 Subscribe not a function

Question

Angular return a error : Error: Uncaught (in promise): TypeError: res.users.subscribe is not a function.

Since this morning, I don't understand what's wrong in my resolve.

UserService.ts

import { Injectable } from '@angular/core';
import { HttpClient, HttpHeaders } from '@angular/common/http';
import { Observable } from 'rxjs/Observable';

@Injectable()
export class UsersService {

    private api = 'http://localhost:3000/users';
    private headers = new HttpHeaders();

    constructor(
        private http: HttpClient
    ) {}

     getAllUsers(): Observable<any[]> {
         return this.http.get<any[]>(this.api, {headers: this.headers, responseType: 'json' });
    }
}

---

UserResolve.ts:

import { Injectable } from '@angular/core';
import { Resolve } from '@angular/router';
import { UsersService } from '../services/users.service';

@Injectable()
export class UsersResolve implements Resolve<any> {

    constructor(private usersService: UsersService) {}

    resolve() {
       return this.usersService.getAllUsers();
    }
}

---

UserComponent.ts

import { Component, OnInit } from '@angular/core';
import { ActivatedRoute } from '@angular/router';

import {Users} from '../_shared/models/Users';

@Component({
  selector: 'app-user',
  templateUrl: './users.component.html',
  styleUrls: ['./users.component.sass']
})

export class UsersComponent implements OnInit {

    constructor(private route: ActivatedRoute) {}

    public title: string;
    public users: Users[] = [];

    ngOnInit() {
        this.route.data.forEach((res: any): any => {
           this.title = res.title;
           res.users.subscribe(users =>  {
              console.log(users);
              this.users = users;
           });
        });
    }
}

When I log res.users, it return "function UsersResolve()" with not proto subscribe...

The json is Array of Object like :

{
  id: 13246,
  guid: '46ffgd456dfs',
  name: 'John Doe',
  adress: ...
}

Can the problem come from the contents of my json ?

Originally, I wanted to train on the RxJS operator...

Solution 1

you can access the resolved data in two ways

ActivatedRoute data Property which holds the static and resolved data of the current route
ActivatedRouteSnapshot: the no-observable alternative.

you need to add resolve property to the route configuration, which is an object where each key points to a resolver.

    const appRoutes: Routes = [{ path: 'users', component: UsersComponent, 
         data: { title : 'Liste des Utilisateurs'},
          resolve:{ users : UsersResolve } } 
]

Approach-1

 ngOnInit() {
        this.route.data.subscribe(value=>{

   this.title=value.title;
    this.users=value.user;
});

    }

Approach:2

ngOnInit() {

       this.title=this.route.snapshot.data.title;
        this.users=this.route.data.snapshot.user;


        }

STACKBLITZ DEMO

Solution 2

You're applying subscribe on Array. You should do it on Observable.

Try to apply below changes.. You can perform operations on data once you understand it's value on console.

UserComponent.ts

import { Component, OnInit } from '@angular/core';
import { ActivatedRoute } from '@angular/router';
import {Users} from '../_shared/models/Users';

@Component({
  selector: 'app-user',
  templateUrl: './users.component.html',
  styleUrls: ['./users.component.sass']
})

export class UsersComponent implements OnInit {

    constructor(private route: ActivatedRoute) {}

    public title: string;
    public users: Users[] = [];

    ngOnInit() {
        this.route.data.subscribe(data => console.log(data));
    }
}

UPDATE

As mentioned in Comments:

if you've defined routes like this:

const appRoutes: Routes = 
[ ... 
 { path: 'users',
   component: UsersComponent,
   resolve: { 
     users : UsersResolve 
   } 
 } 
];

The you should be able to get the data as:

ngOnInit() {
        this.route.data.subscribe(data => console.log(data['users']));
    }

Solution 3

From de angular.io doc:

interface ActivatedRoute {
  snapshot: ActivatedRouteSnapshot
  url: Observable<UrlSegment[]>
  params: Observable<Params>
  queryParams: Observable<Params>
  fragment: Observable<string>
  data: Observable<Data>
  outlet: string
  component: Type<any> | string | null
  get routeConfig: Route | null
  get root: ActivatedRoute
  get parent: ActivatedRoute | null
  get firstChild: ActivatedRoute | null
  get children: ActivatedRoute[]
  get pathFromRoot: ActivatedRoute[]
  get paramMap: Observable<ParamMap>
  get queryParamMap: Observable<ParamMap>
  toString(): string
}

That data is the observable himself. Try:

this.route.data.subscribe(data =>  {
      console.log(data);
   });
});

Remember, subscribe is the ear to an observable voice.

Solution 4

The above answers are right on, but I ran into a special case of this.

The method being called was an observable and was used in other parts of the application as an observable, yet when I ran it, it was saying the dreaded subscribe is not a function.

The issue was, I was running in Jasmine unit tests, I had defined a custom mock, and that mock was not returning an observable. In such cases it is easy to goof up the mock and return a different type then the actual function being mocked returns. Correcting my mock fixed my issue.

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Comments

[Reuno92]

It log same thing : Object { title: 'user list, users : function UsersResolve() }

[Pavankumar Shukla]

I thought you've passed this static data as you mentioned in comments. it should be.. { path: 'users', component: UsersComponent, resolve: { users : UsersResolve } }... let me update the answer

[Sujit Y. Kulkarni]

Props for the last line. Describes Subscribe observable in one line.