Unable to Fetch Data from JSON File Using HttpClient in Angular 18

Question

I am new to Angular 18 and have been trying to read a JSON file using an observable with an HTTP call. Despite following several online tutorials and forum solutions, I am still encountering issues.

My Setup

I created a service that makes an HTTP request to read a JSON file. I have verified that the path to the file is correct. However, I am not receiving any data, and I noticed that it says HttpClientModule is deprecated.

Code Snippets

EmployeeService (employee.service.ts)

import { HttpClient } from '@angular/common/http';
import { Injectable } from '@angular/core';
import { Observable } from 'rxjs';
import { IEmployee } from './employeeInterface'; 

@Injectable({
  providedIn: 'root'
})
export class EmployeeService {
  private _dataUrl: string = '/assets/data/employees.json';

  constructor(private http: HttpClient) { }

  getEmployees(): Observable<IEmployee[]> {
    return this.http.get<IEmployee[]>(this._dataUrl);
  }
}

AppModule (app.module.ts)

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from '@angular/forms';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { MyTestPageComponent } from './my-test-page/my-test-page.component';
import { EmployeeListComponent } from './employee-list/employee-list.component';
import { EmployeeDetailsComponent } from './employee-details/employee-details.component';
import { EmployeeService } from './employee.service';
import { HttpClientModule } from '@angular/common/http';  

@NgModule({
  declarations: [
    AppComponent,
    MyTestPageComponent,
    EmployeeListComponent,
    EmployeeDetailsComponent
  ],
  imports: [
    BrowserModule,
    AppRoutingModule,
    FormsModule,
    HttpClientModule
  ],
  providers: [EmployeeService],
  bootstrap: [AppComponent]
})
export class AppModule { }

EmployeeListComponent (employee-list.component.ts)

import { Component, OnInit } from '@angular/core';
import { IEmployee } from '../employeeInterface';
import { EmployeeService } from '../employee.service';

@Component({
  selector: 'app-employee-list',
  template: `
    <h2>Employee List</h2>
    <ul *ngFor="let employee of employeesList">
      <li>{{ employee.name }}</li>
    </ul>
  `,
  styles: []
})
export class EmployeeListComponent implements OnInit {
  public employeesList: IEmployee[] = [];

  constructor(private employeeService: EmployeeService) { }

  ngOnInit(): void {
     this.employeeService.getEmployees().subscribe(data => this.employeesList = data);
   
  }
}

EmployeeInterface.ts

export interface IEmployee {
  id: number;
  name: string;
  age: number;
}

Additional Information

The JSON file (employees.json) is located in src/assets/data and has the correct format. There are no errors in the console, but the data is not being fetched. I noticed a message indicating that HttpClientModule is deprecated, but I can't find any clear guidance on what to use instead.

I would appreciate any guidance or suggestions on how to resolve this issue. Thank you!

Answer 1

Please ensure that you configure the assets folder to allow accessing files & folders in the angular.json.

"assets": ["src/assets"]

Make sure your employees.json contains a JSON array.

[
  {
    "id": 1,
    "name": "Emp One",
    "age": 44
  }
]

Besides, you are not using the employeeService in your EmployeeListComponent.

ngOnInit(): void {
  this.employeeService
    .getEmployees()
    .subscribe((data) => (this.employeesList = data));
}

Demo @ StackBlitz