State Modules

State Modules is an immutable state management library allowing the orchestration of your state in an efficient and predictable way. State Modules is largely reactive and maintains many powerful models for handling asynchronous scoping in a lazy way.

State Modules use ES6 Proxies to capture mutations performed against a "draft state". If changes occur while reducing a dispatched action, updates are dispatched directly to only those components which have subscribed to changes for the given values.

Note: While reducers "appear" to be mutating the state, they are actually mutating an ES6 Proxy. References are then changed based on those mutations so that nextState !== state if any values change at any depth within the state.

Installation

yarn add state-modules

Documentation

• Reference Documentation
• Examples

Libraries

• react-state-modules

Simple Examples

State Manager

import createState from "state-modules";

const state = createState();

const created = Date.now();

state.component({
  config: { cid: "counter" },
  state: {
    counter: {
      created,
      updated: created,
      value: 0
    }
  },
  selectors: {
    counterValue: "counter.value"
  },
  actions: {
    increment: ["by"],
    decrement: ["by"]
  },
  reducers: {
    INCREMENT(draft, { by = 1 }) {
      draft.counter.value += by;
      draft.counter.updated = Date.now();
    },
    DECREMENT(draft, { by = 1 }) {
      draft.counter.value -= by;
      draft.counter.updated = Date.now();
    }
  }
});

state.actions.increment(5);
state.actions.decrement(1);
state.actions.decrement();

// get the selector 'counterValue' and return results
const currentValue = state.select("counterValue"); // 3