this is not allowed in case of canonical MVP also...

# rx

[adolgiy]

this is not allowed in case of canonical MVP
also i’m use Moxy library for MVP (it’s awesome lib) and Moxy crashes on compile with view method returning non-void value

[artem_zin]

Moxy crashes on compile with view method returning non-void value

facepalm.jpg

[adolgiy]

why?

[artem_zin]

Why would MVP library even do that?

[adolgiy]

because of:
1. that is creator’s decision
2. this is rule of canonical MVP

[artem_zin]

Ah, so it basically prohibits you from reading state of View layer, it makes some sense then, but it makes RxBinding pretty useless for you in that case

[adolgiy]

some good guys do presenter.setButtonObservable(RxView.clicks(button))

[adolgiy]

but I think this is ugly

[artem_zin]

yeah, feels like wrong indirection and I’m not sure how would you compose that with Presenter logic, Observable<Observable>?

[adolgiy]

nope, i decide to duplicate observable for view in presenter with RxRelay and transfer all data through presenter’s plain methods. Feels good, but a bit complicated.
Also add to Presenter#unsubscribeOnDetach(Disposable) to give control on RxBinding’s subscriptions to presenter

[artem_zin]

So you have a pair of Disposable and Relay for each observable from View layer?

[adolgiy]

Simplified version:
https://gist.github.com/adolgiy/77f2ee9ba39f8ca403858b4307aa01a5

[adolgiy]

I have Relay for each view I need to react on different Rx thing.
For example, button state depends on symbol count on multiple `EditText`s, so combining internal Relay is easy.

[artem_zin]

Mhm, I see, do you manage .subscribe(presenter::onEditTextChanged) Disposable?

[adolgiy]

Yep, previous line - doOnSubscribe(presenter::unsubscribeOnDetach)

[artem_zin]

Ookay, that’s pretty non-obvious way to unsubscribe 😄 I mean I don’t think anybody would expect unsubscription management through separate side effect as doOnSubscribe(), it’ll work though

[artem_zin]

I still don’t see much benefit from such two way binding though, you need to manage disposables both on View and Presenter layer

[adolgiy]

yes, i agree, this solution is a little bit overcomplicated