我应该在Angular中再次调用ngOnInit（）吗？

Question

I am new to Angular and the question may sound stupid. Please bear with me.

I have defined my ngOnInit like:

ngOnInit() {
 this.rowData = this.studentService.getStudents();//Make http calls to populate data
}

And in an event I call ngOnInit again as I need to reload the data:

onSomeEvent(){
 this.ngOnInit();
}

Is this OKAY? Or I should write the line to call http again if ngOnInit() is a costly method.

Answer 1

No, this is not a good practice.

Better is to call some method from ngOnInit and reCall the same method when needed. Like this-

ngOnInit() {
 this.onLoad();
}

onLoad() {
this.rowData = this.studentService.getStudents();//Make http calls to populate data
}

onSomeEvent(){
 this.onLoad();
}

Answer 2

The better way to do it :

ngOnInit(){
this.loadData();
}

//load data

loadData(){
this.rowData = this.studentService.getStudents();
}

//on change event
ngOnChanges(){
this.loadData()
}

//capture data on other event
otherEvent(){
this.loadData()
}

Answer 3

ngOnInit is lifecycle hook that is called after data-bound properties of a directive are initialized so first time it call by angualr it self , so recalling this method will case alot of confusing to other and sign to poor code , so it better to break the code insde ngOnInit and called againg if need it.

ngOnInit() {
 this.refrechItems();
}

public refrechItems(): void {
  // magic things
} 

you may cosider samething for all other lifecycle hooks

Answer 4

Please do not do that! Angular has many different Lifecycle hooks

https://angular.io/guide/lifecycle-hooks