Table of Contents

• Install
• Usage
• API

Install

$ npm install --save @jessemc98/simple-store

Then with a module bundler like rollup or webpack, use as you would anything else:

// using ES6 modules
import createStore from '@jessemc98/simple-store'

// using CommonJS modules
var createStore = require('@jessemc98/simple-store')

Basic Usage

function numberReducer(state, event) {
  switch (event.type) {
    case "increment":
      return state + 1
    case "decrement":
      return state - 1
    default:
      return state
  }
}
const subscribers = { number: numberReducer }
const initialState = { number: 10 }

const store = createStore(subscribers, initialState)

store.emit({type: "increment"})
// expect(store.getState().number).toEqual(11)
store.emit({type: "decrement"})
// expect(store.getState().number).toEqual(10)

API

createStore

simple-store is an experimental way to deal with state in javascript, inspired by redux.

Returns simple-store

Parameters

• reducers Object Required. Object full of Reducer functions.
• initialState Object Object with the same shape as reducers parameter with initial values to set to state.

emit

Calls all reducers in store with event and current state and sets the new state to the value returned by the reducers.

Parameters

• event Custom event object Required. An event object to emit.

getState

Returns the current state of the store. Do not mutate any values of the returned object directly, emit events whenever you want to cause a state change otherwise subscribers will not fire.

subscribe

Subscribe to a given key in state.

Parameters

• key String Required. Key in state to watch for changes.
• callback Function Handler function to call with new value of state[key] whenever its value changes.

unsubscribe

Unsubscribe previously added subscriber from key in state.

Parameters

• key String Required. Key in state to remove callback from.
• callback Function Handler function to remove from any subscribers of state[key].

Custom event object

Object you need to pass to emit method. The only limitation is the type property is required and must be a String but otherwise it can be any javascript object with any properties.

Properties

• type String Required. Type of event to emit.

Reducer function

A js function which is called with state and event every time an event is emitted. State is set to the return value when a reducer is called.

If state is mutated but the same object is returned subscribers will not be called so if state changes the function should return a new object.

Injected parameters

• state any js value Current state.
• event Custom event Object The event which was emitted that caused reducers to be called.