GaramX

A class with a specific purpose.

1. Share data
2. Implement application logic
3. External Interaction

Naming convention - .service.ts

import { Injectable } from '@angular/core';
 
// @Injectable({
//   providedIn: 'root'
// })
@Injectable()
export class EmployeeService {
 
  constructor() { }
 
  getEmployees(){
    return [
      { id: 3, name: "둘리", age: 100030 },
      { id: 4, name: "고길동", age: 30 },
      { id: 5, name: "희동이", age: 30 },
      { id: 5, name: "고철수", age: 30 },
    ];
  }
}

HttpClient

import { Injectable } from '@angular/core';
import { HttpClient, HttpErrorResponse } from '@angular/common/http';
import { IEmployee } from './employee';
//import { Observable } from 'rxjs';
import { throwError } from 'rxjs';
import { catchError, retry } from 'rxjs/operators';
 
// @Injectable({
//   providedIn: 'root'
// })
@Injectable()
export class EmployeeService {
  private _url: string = "/assets/data/employees.json"
 
  constructor(private http: HttpClient) { }
 
  getEmployees(): Observable<IEmployee[]>{
    return this.http.get<IEmployee[]>(this._url)
      .pipe(
        catchError(this.errorHandler)
      );
  }
  errorHandler(error: HttpErrorResponse){
    return throwError(error);
  }
}