Storing reference to data from service on the component

[sinful eagle]

Keep in mind that mutations will be reflected, but reference changings will not.

[tacit oasis]

When you say reference changings, do you mean redefining this.dataObj to be a different object? eg:

fetchSomeNewData() {
  this.http.get('some url').suscribe(newObj => {
    this.dataObj = newObj;
  });
}

[sinful eagle]

Assuming that's inside the service, yes.

[tacit oasis]

Yeah I guess that could be seen as a valid use case if your expecting to only use that data from the service temporarily. But even then I think a getter would be safer:

private _newDataObj;

get dataObj() {
  return this._newDataObj || this.service.dataObj;
}

fetchSomeNewData() {
  // fetch the data and set it to this._newDataObj;
}

[sinful eagle]

Why not exposing an observable as everyone else does?

[tacit oasis]

So basically the same thing, except for using observables and pipe? Or am I misunderstanding what you are suggesting?

[sinful eagle]

The getter is not different than accessing the data.
To get a fresh copy of th evalue you should call it explicitly.
With Observable you leverage a "Push" pattern, where the component will be notified of a new value without you having to poll for it.