How to call ngOnInit() again in Angular 2?

Question

Please explain in this code, how to call ngOnInit() again when I call another method?

ngOnInit(): void {
  this.route.params.subscribe((params: Params) => {
    this.model = this.userData;
  });
}

update() {
  this.loading = true;
  this.userService.update(this.model).subscribe(
    (data) => {
      alert('Update successful');
    },
    (error) => {
      alert('Not updated');
      this.loading = false;
    },
  );
  this.user_data();
}

Implantation

What's the purpose? Just move the code to another method and call that method from ngOnInit(). ngOnInit() is called once for every method. There is no way to make it being called multiple times. – Blida

please explain me for updated code – Implantation

Answer 1

There are two options from my point of view:

Calling ngOnInit() from another function scope. But I would suggest to do not adopt this approach given ngOnInitis an angular core method that belongs to OnInit Interface.

    public ngOnInit() {
          this.route.params.subscribe((params: Params) => {
          this.model=this.userData;
      });      
    }
    
    update() {
           this.ngOnInit();
    }  

Break your functionality into another function, use ngOnInitto call it and, afterwards, any request can be made from anywhere by calling the function in the following manner: this.<MethodName>();.

    public ngOnInit() {
          this.getRouteData();
    }
    
    update() {
           this.getRouteData(); 
    }

    getRouteData() {
      this.route.params.subscribe((params: Params) => {
          this.model=this.userData;
      }); 
    }    

Cloninger

Answer 2

If the purpose is to trigger ngOnInit() when query param is updated, then do following:

import { Router } from '@angular/router';
constructor(private router: Router) {
    this.router.routeReuseStrategy.shouldReuseRoute = () => false;
}

Mehalick

This is exactly the solution I was looking for. Big thank you Hari – Roumell

But this will affect if you have routerLink to go in other routes it will not work. Tested by myself – Joyance

Answer 3

ngOnInit called once the component is created. so you can create a function and call the function again. Here is the sample code.

ngOnInit(): void {
    this.callFun();
}    

update() {
    this.callFun();
    // do code
}

private callFun(){
   // do code
}

Gorgon

Answer 4

You should not need to call ngOnInit again. So the question remains, what are you really trying to accomplish? Are you having issues retrieving the routing parameter?

 ngOnInit(): void {
      this.route.params.subscribe((params: Params) => {
        this.model=this.userData;
  }); 

Your code within the subscribe above will AUTOMATICALLY be re-executed every time the route parameters change. So there is no need to manually call ngOnInit again.

Squatness

Answer 5

It's just a function ...

ngOnInit() {}

secondMethod() { this.ngOnInit(); }

I've been doing it all the time to reload my data, never had a problem with it.

Vitascope

you should not call ngOnInit life cycle from another custom function – Hoad

@Mdomerarafat Could you explain why not? – Haem