Revive.js; A simple implementation of the awesome http://redux.js.org/

revive.js

const Revived = () => {
  
  createStore = (reducer) => {
    let state
    let listeners = []
  
    const getState = () => state
  
    const dispatch = (action) => {
      state = reducer(state, action)
      listeners.forEach(listener => listener())
    }

    const subscribe = (listener) => {
      listeners.push(listener)
      return () => { 
        listeners = listeners.filter(l => l !== listener)
      }
    }
    
    dispatch({})
    
    return {
      getState,
      dispatch,
      subscribe,
    }
  }
  
  const combineReducers = (reducers) => {
    return (state = {}, action) => {
      return Object.keys(reducers).reduce((nextState, key) => {
        nextState[key] = reducers[key](state[key], action)
        return nextState
      }, {})
    }
  }
  
  return {
    createStore,
    combineReducers, 
  }
}


/* Usage */
const { combineReducers, createStore } = Revived()

/* 1. Action Constants */ 
const FOO = 'FOO'
const BAR = 'BAR'
 
/* 2. Action Creators */
const doFoo = (data) => ({
  type: FOO,
  data,
})

const dobar = (data) => ({
  type: BAR,
  data,
})

/* 3. Reducers */
const reducerOne = (state = [], action) => {
  switch (action.type) {
    case FOO:
      return [
        ...state,
        {
          data: action.data,
        }
      ]
    default:
      return state
  }
}

const reducerTwo = (state = {}, action) => {
  switch (action.type) {
    case BAR:
      return Object.assign({}, state, {
        data: action.data,
      })
    default:
      return state
  }
}

/* 4. Combine Reducers */
const allReducers = combineReducers({
  reducerOne,
  reducerTwo,
})

/* 5. Create Store */
const store = createStore(allReducers)

/* 6. Action Dispatchers */
const dispatchDoFoo = (data) => store.dispatch(doFoo(data))
const dispatchDoBar = (data) => store.dispatch(doBar(data))

/* Example implementation */
const elements = document.getElementsByClassName('item')

Array.prototype.forEach.call(elements, (element) => {
  element.addEventListener('click', (e) => {   
    dispatchDoFoo(e.target.innerText)
    console.log(store.getState())
  })
})