Angular Component constructor loads twice when httpClient is called from Constructor

Question

Angular constructor loads twice when httpClient functions are called from the same constructor.

       export class ViewOrderDetailsComponent {
            constructor(
                   private activatedRoute: ActivatedRoute,
                   private router: Router,
                   private httpClient:HttpClient) {
        console.log("_______________constructor____________");   
    this.httpClient.get("https://jsonplaceholder.typicode.com/todos/1",{headers: null, params:null}).subscribe();
   //constructor loads once if above line is commented.
           
                }
        }

Is it not suggested to make api call from constructor?

why don't you call that API in ngOnInit? – Arokia Lijas Apr 19 '22 at 11:00 — Arokia Lijas, Apr 19 '22 at 11:00

score 0 · Answer 1 · answered Apr 19 '22 at 10:35

there is no way to loads constructor of component twice without destroy it first so i think there is another part of code in your application is responsible to load your component twice, anyway i also tried your code with some modification because headers and params connot be null and it's work properly without the problem you mention

this.httpClient.get("https://jsonplaceholder.typicode.com/todos",{headers:new HttpHeaders,params:{id:5,completed:false}}).subscribe(data=>{
  console.log(data);
});

and about your question,yes is a bad practice to call api in constructor of a component it prefer to call it from service.i hope that's help you somehow

Angular Component constructor loads twice when httpClient is called from Constructor

1 Answers1