如何从 angular 中的订阅访问在 function scope 上声明的变量

Question

My question is very simple. I have an Angular component, and inside that component, I have a function like this:

somethingCollection: TypeSomething[]
...
public deleteSomething(something: TypeSomething): void {
    // something is in this scope
    this.someAPI.deleteSomething(something.id).subscribe( (res) => {
       // update this.somethingCollection
       // but cannot access something in outer scope
    }
}

As you may have observed, to update this.somethingCollection I need something.id, but inside the subscribe I lost access to it.

Does anyone knows how to access the variables at function scope inside the subscribe?

Answer 1

Overlapping function problems can prevent the value of this from disappearing by storing references to this of the parent function using the scope chain.

so using the word self , context , $this or anything else when you assign the value of this to it. it is locked in place like any other regular variable.

somethingCollection: TypeSomething[]
...
public deleteSomething(something: TypeSomething): void {
    let self = this;
    this.someAPI.deleteSomething(something.id).subscribe( (res) => {
       self.somethingCollection // access somethingCollection....
       // this.somethingCollection is undefined
    }
}

Answer 2

It's not true

export class AppComponent implements OnInit  {
  name = 'Angular ' + VERSION.major;
  constructor(private dataService:DataService){}


  public deleteSomething(something: any): void {
    console.log(something)
    this.dataService.getData(something.id).subscribe( (res) => {
      console.log(something,this.name,res)
    })
  }
  ngOnInit()
  {
    this.deleteSomething({id:3})
  }

}

see a fool stackblitz