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import React from 'react'
import ReactDOM from 'react-dom'
import { createStore, combineReducers } from 'redux'
import * as R from 'ramda'
// composition helper
const combine = R.curry((c, o) => x => (<div>{c(x)} {o(x)}</div>))
const combineComponents = (...args) => {
const [first, ...rest] = args
return R.reduce((acc, c) => combine(acc, c), first, rest)
}
// helpers
const targetValue = e => e.target.value
const getTodos = R.prop('todos')
// redux utils
const createReducer = (init, handlers) =>
(state = init, action) =>
R.propOr(R.identity, R.prop('type', action), handlers)(state, action)
const addOne = R.add(1)
const getAllIds = R.pluck('id')
const getMax = R.reduce(R.max, 0)
const getNextId = R.compose(addOne, getMax, getAllIds)
// constants
const ADD_TODO = 'ADD_TODO'
const DELETE_TODO = 'DELETE_TODO'
// actions
const addTodo = text => ({type: ADD_TODO, text })
const deleteTodo = id => ({ type: DELETE_TODO, id })
// reducers
const todos = createReducer([], {
[ADD_TODO]: (state, action) => [
{ id: getNextId(state), completed: false, text: action.text },
...state
],
[DELETE_TODO]:(state, action) => R.reject(R.propEq('id', action.id), state),
})
const year = createReducer('', {})
const title = createReducer('', {})
// combine reducer and create store
const reducers = combineReducers({todos, year, title})
const initialState = {
year: '2016',
title: 'Random stuff',
todos: [{id:1, text: 'foo'}, { id:2, text: 'bar'}]
}
const store = createStore(reducers, initialState)
// components
const Header = title => <h1>A Todo List: {title}</h1>
const Add = ({onSave}) => (
<div>
<button onClick={() => onSave('foobar')}>Add</button>
</div>
)
const List = items => <ul>{items}</ul>
const Item = ({todo, onDelete}) => (
<li key={todo.id}>
{todo.text} <button onClick={() => onDelete(todo.id)}>Remove</button>
</li>
)
const Footer = text => <div>{text}</div>
// define a bindActionCreator
const bindAction = R.curry((dispatch, actionCreator) =>
R.compose(dispatch, actionCreator))
const bindActionCreator = bindAction(store.dispatch)
// map state to props
const TodoHeader = R.pipe(props => props.title, Header)
const TodoAdd = R.pipe(props => ({onSave: props.dispatch(addTodo)}), Add)
const mapItems = ({todos, onDelete}) =>
R.map(todo => Item({todo, onDelete}), todos)
const TodoList = R.pipe(props =>
({todos: props.todos, onDelete: props.dispatch(deleteTodo)}),
R.compose(List, mapItems)
)
const TodoFooter = R.pipe(props => props.year, Footer)
// combine all components
const App = combineComponents(TodoHeader, TodoAdd, TodoList, TodoFooter)
// we could also have used curry...
const getRender = node => app => ReactDOM.render(app, node)
const render = getRender(document.getElementById('root'))
const run = store.subscribe(() =>
render(<App {...store.getState()} dispatch={bindActionCreator} />))
// start
const init = store.dispatch({type: '@@INIT'})
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