iOS RxSwift - how to “disconnect” an observable?

Question

I am building an aggregator class that connects multiple observables and emits a single sequence of emissions from these observables:

5 inputs from sources go in, one input comes out from ReplaySubject .

Is there a way to manage subscriptions within this aggregator to allow one of the sources to “disconnect” without breaking the whole chain?

Would keeping a dictionary of [Observable: Subscription ] help to be able to cancel a specific subscription?

Answer 1

It sounds like you might benefit from having something like a Store object (reproduced below.)

Your store is bound to your input sources. (as in myInput.bind(to: myStore).disposed(by: bag) ) and the outputs are bound to the store's state. (as in myStore.state.bind(to: myOutput).disposed(by: bag) )

The inputs can disconnect by completing and the outputs can disconnect by disposing the associated disposable.

The reducer's job is to convert an input into an output.

//
//  Store.swift
//
//  Created by Daniel Tartaglia on 3/11/17.
//  Copyright © 2017 Haneke Design. MIT License
//
import Foundation
import RxSwift


class Store<State, Action> {

    init(initialState: State, reducer: @escaping (State, Action) -> State) {
        state = actions
            .scan(initialState, accumulator: reducer)
            .startWith(initialState)
            .share(replay: 1)
    }

    let state: Observable<State>

    private let actions = PublishSubject<Action>()
}


extension Store: ObserverType {

    typealias E = Action

    func on(_ event: Event<E>) {
        actions.on(event)
    }
}