In my Angular 2 app I have the following:

  ngOnInit() {
    debugger;
    this.activatedRoute.paramMap.subscribe((params) => {
      this.rowid = params.get('rowid')
      
      this.apiService.getrow(this.rowid).subscribe((data) => {
        this.data = data;
        //Validations
        if (this.data == null) return;
        if (!("oid" in data)) return;
        let oid:string =data["oid"]
      })
    })
  }
}

This seems wrong because every time the params change we create a new api service call that create a new subscription. I rather not use activatedRoute snapshot.
Is there a better pattern for this. Is there a better way to do this?

CodePudding user response：

You can go with a pipe:

import { take } from 'rxjs/operators';

this.apiService.getrow(this.rowid).pipe(take(1)).subscribe(...)

and it will take a value from sub and unsubscribe.

If you don't want to watch for url params changes, you can consider using BehaviorSubjects. Thus, you can create a service that gets and sets the rowid value as a BehaviorSubject, and then subscribe to it instead of the router. Inside that subscription, you can subscribe to api service (and you can also use take1 there).