this.store.dipatch.subscribe(value => {}) in case of action success value is state, otherwise it is error

[AlgoTrader]

this.store.dipatch.subscribe(value => {})

When action was success value is state When action errored value is error

As a result, I always have to inspect value type in subscribe callback of any dispatch Also 'DISPATHCED' and 'COMPLETED' are capitalized. but 'Errored' is first capitalized

[deebloo]

I think that is a bug in that we don't want any value coming out of the subscribe. @amcdnl is that correct?

[AlgoTrader]

I would prefer this.dispatch(new Action) to push value on success and throw on error

this.dispatch(new DoComplexStuff)
   .subscribe(successCb. errorCb)

Now if action throws, I get successCb with error value. I don't like values that I have to deep inspect to decide dispatch was success or failure

[deebloo]

ah I see. Let me take a look and see how we are handling these errors

[juristr]

When action was success value is state

Also, the question is whether this is actually desired. Because right now, since a successful dispatch returns the entire state obj (which IMHO is useless), the following code from the docs also wouldn't work any more:

export class ZooComponent {
  @Select(state => state.animals) animals$: Observable<any>;
  constructor(private store: Store) {}
​
  addAnimal(name) {
    this.store.dispatch(new AddAnimal(name))
      .pipe(withLatestFrom(this.animals$))
      .subscribe(([animals]) => {
        // do something with animals
        this.form.reset();
      });
  }
}

Because now the value of the .subscribe(..) would be an array having as first value the entire state tree and as 2nd value (in this case) the last value from animals$.

Personally I'd prefer not having a return value from the action because it diverges a bit from the CQRS pattern, where you should separate "writes" from "reads". I'm perfectly fine to be able to subscribe to know when the action "is done".

[AlgoTrader]

I also think the entire state in callback is useless. First, I can select any state slice if I need it. Second, I often want to know the result of the last dispatch. I would prefer to see the result of action but not the whole state

[deebloo]

I agree with both of you. So there are two parts.

1. no state should back in the callback.
2. if there is an error it should fire the subscribers errors callback

[AlgoTrader]

Exactly. Errors should be explicit

[amcdnl]

I agree w/ @deebloo

[amcdnl]

I believe this is resolved in 3.0

[juristr]

@amcdnl "believing" is not enough Austin. We want proof 😉. As soon as I can I'm gonna test it and let you know in case