Unidirectional Reactive Architecture. This is a Combine implemetation of ReactiveFeedbback and RxFeedback
Requirements for iOS apps have become huge. Our code has to manage a lot of state e.g. server responses, cached data, UI state, routing etc. Some may say that Reactive Programming can help us a lot but, in the wrong hands, it can do even more harm to your code base.
The goal of this library is to provide a simple and intuitive approach to designing reactive state machines.
State
is the single source of truth. It represents a state of your system and is usually a plain Swift type. Your state is immutable. The only way to transition from one State
to another is to emit an Event
.
Represents all possible events that can happen in your system which can cause a transition to a new State
.
A Reducer is a pure function with a signature of (State, Event) -> State
. While Event
represents an action that results in a State
change, it's actually not what causes the change. An Event
is just that, a representation of the intention to transition from one state to another. What actually causes the State
to change, the embodiment of the corresponding Event
, is a Reducer. A Reducer is the only place where a State
can be changed.
While State
represents where the system is at a given time, Event
represents a state change, and a Reducer
is the pure function that enacts the event causing the state to change, there is not as of yet any type to decide which event should take place given a particular current state. That's the job of the Feedback
. It's essentially a "processing engine", listening to changes in the current State
and emitting the corresponding next events to take place. Feedbacks don't directly mutate states. Instead, they only emit events which then cause states to change in reducers.
To some extent it's like reactive Middleware in Redux having a signature of (AnyPublisher<State, Never>) -> AnyPublisher<Event, Never>
allows us to observe State
changes and perform some side effects based on its changes e.g if a system is in loading
state we can start fetching data from network.
This repo contains an example of UIFeedback loop inspired by the work of @Krunoslav Zaher in RxFeedback-React specifically here.
Why UI
can be treated as a Feedback
loop:
- To some extent, UI is a part of the system. When the state changes we want to react to it and render new information to the user.
- User may interact with our system by pressing buttons and views emitting
Event
into it
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