damonyuan / redux

Redux like StateMachine

README

State Machine

State Machine example uising DFA (Deterministic Finite Automation).

Entries at top first row are inputs, entries at the left first column are the states.

	AaaToBbbAction	BbbToCccAction	BbbToFinalAction	CccToFinalAction	Others
AaaState	BbbState	AaaState	AaaState	AaaState	AaaState
BbbState	BbbState	CccState	FinalState	BbbState	BbbState
CccState	CccState	CccState	CccState	FinalState	CccState
FinalState	FinalState	FinalState	FinalState	FinalState	FinalState

Pros

• Better for Event Driven Design - one action / event might have multiple different handlers in different components.
• Extensible - adding one State doesn't impact the other states.
• Handler mapping to each dispatched action/event is managed by the state machine itself; There is no necessary for Action/Event issuer to understand the which action/handler method to call explicitly

Cons

• Based on the Action / Event name to find the corresponding handler defined in state, switch-case is unpreventable.
• Types of payload are unknown to the handler, runtime inference is required.

State Pattern

Another implementation of State (Machine) Pattern.

Pros

• Switch-case is prevented
• The types of payload for each action handler is clearly defined.

Cons

• Adding one action for one state will impact all the other states.
• Switch-case is still required before calling the handler function inside the action if Even-Driven design is used by the system.
• Needs to understand which action/handler method to call at each step.

Redux

Java version of Redux implementation.

newState = reducer.reduce(currentState, payload).

Popular in React JS.

another

Let’s learn how modern JavaScript frameworks work by building one