Redux Todos Example

此项目模板是使用Create React App构建的，它提供了一种简单的方法来启动React项目而无需构建配置。
使用Create-React-App构建的项目包括对ES6语法的支持，以及几种非官方/尚未最终形式的Javascript语法
先看效果

这个例子可以帮助你深入理解在 Redux 中 state 的更新与组件是如何共同运作的。
展示了 reducer 如何委派 action 给其它 reducer，也展示了如何使用 React Redux 从展示组件中生成容器组件。

//index.js 跟组件
import React from 'react'
import { render } from 'react-dom'
import { createStore } from 'redux'
import { Provider } from 'react-redux'
import App from './components/App'
import rootReducer from './reducers'
const store = createStore(rootReducer)
render(
<Provider store={store}>
<App />
</Provider>,
document.getElementById('root')
)

先看action,action是对象

let nextTodoId = 0
// Action 本质上是 JavaScript 普通对象。我们约定，action 内必须使用一个字符串类型的 type 字段来表示将要执行的动作。
// 多数情况下，type 会被定义成字符串常量。当应用规模越来越大时，建议使用单独的模块或文件来存放 action。
export const addTodo = text => ({
type: 'ADD_TODO',
id: nextTodoId++,
text
})
export const setVisibilityFilter = filter => ({
type: 'SET_VISIBILITY_FILTER',
filter
})
export const toggleTodo = id => ({
type: 'TOGGLE_TODO',
id
})
export const VisibilityFilters = {
SHOW_ALL: 'SHOW_ALL',
SHOW_COMPLETED: 'SHOW_COMPLETED',
SHOW_ACTIVE: 'SHOW_ACTIVE'
}

接下来看reducer
这个是combineReducers

import { combineReducers } from 'redux'
import todos from './todos'
import visibilityFilter from './visibilityFilter'
export default combineReducers({
todos,
visibilityFilter
})

这个是reducer操作纯函数

//纯函数操作state
const todos = (state = [], action) => {
switch (action.type) {
case 'ADD_TODO':
return [
...state,
{
id: action.id,
text: action.text,
completed: false
}
]
case 'TOGGLE_TODO':
return state.map(todo =>
(todo.id === action.id)
? {...todo, completed: !todo.completed}
: todo
)
default:
return state
}
}
export default todos

visibilityFilter.js中是进行过滤函数

import { VisibilityFilters } from '../actions'
const visibilityFilter = (state = VisibilityFilters.SHOW_ALL, action) => {
switch (action.type) {
case 'SET_VISIBILITY_FILTER':
return action.filter
default:
return state
}
}
export default visibilityFilter

//app.js
//这个是根APP组件
import React from 'react'
import Footer from './Footer'
import AddTodo from '../containers/AddTodo'
import VisibleTodoList from '../containers/VisibleTodoList'
const App = () => (
<div>
<AddTodo />
<VisibleTodoList />
<Footer />
</div>
)
export default App

这个是footer.js

//这是一个footer组件
import React from 'react'
import FilterLink from '../containers/FilterLink'
import { VisibilityFilters } from '../actions'
const Footer = () => (
<div>
<span>Show: </span>
<FilterLink filter={VisibilityFilters.SHOW_ALL}>
All
</FilterLink>
<FilterLink filter={VisibilityFilters.SHOW_ACTIVE}>
Active
</FilterLink>
<FilterLink filter={VisibilityFilters.SHOW_COMPLETED}>
Completed
</FilterLink>
</div>
)
export default Footer

//link组件
import React from 'react'
import PropTypes from 'prop-types'
const Link = ({ active, children, onClick }) => (
<button
onClick={onClick}
disabled={active}
style={{
marginLeft: '4px',
}}
>
{children}
</button>
)
Link.propTypes = {
active: PropTypes.bool.isRequired,
children: PropTypes.node.isRequired,
onClick: PropTypes.func.isRequired
}
export default Link

//todo组件
import React from 'react'
import PropTypes from 'prop-types'
const Todo = ({ onClick, completed, text }) => (
<li
onClick={onClick}
style={{
textDecoration: completed ? 'line-through' : 'none'
}}
>
{text}
</li>
)
Todo.propTypes = {
onClick: PropTypes.func.isRequired,
completed: PropTypes.bool.isRequired,
text: PropTypes.string.isRequired
}
export default Todo

这个是todoList组件

import React from 'react'
import PropTypes from 'prop-types'
import Todo from './Todo'
const TodoList = ({ todos, toggleTodo }) => (
<ul>
{todos.map(todo =>
<Todo
key={todo.id}
{...todo}
onClick={() => toggleTodo(todo.id)}
/>
)}
</ul>
)
TodoList.propTypes = {
todos: PropTypes.arrayOf(PropTypes.shape({
id: PropTypes.number.isRequired,
completed: PropTypes.bool.isRequired,
text: PropTypes.string.isRequired
}).isRequired).isRequired,
toggleTodo: PropTypes.func.isRequired
}
export default TodoList

接下来展示了如何使用 React Redux 从展示组件中生成容器组件。
在container中的是AddTodo.js

//addtodo.js
import React from 'react'
import { connect } from 'react-redux'
import { addTodo } from '../actions'
const AddTodo = ({ dispatch }) => {
let input
return (
<div>
<form onSubmit={e => {
e.preventDefault()
if (!input.value.trim()) {
return
}
dispatch(addTodo(input.value))
input.value = ''
}}>
<input ref={node => input = node} />
<button type="submit">
Add Todo
</button>
</form>
</div>
)
}
export default connect()(AddTodo)

//FilterLink.js
import { connect } from 'react-redux'
import { setVisibilityFilter } from '../actions'
import Link from '../components/Link'
const mapStateToProps = (state, ownProps) => ({
active: ownProps.filter === state.visibilityFilter
})
const mapDispatchToProps = (dispatch, ownProps) => ({
onClick: () => dispatch(setVisibilityFilter(ownProps.filter))
})
export default connect(
mapStateToProps,
mapDispatchToProps
)(Link)

//VisibleTodoList.js
import { connect } from 'react-redux'
import { toggleTodo } from '../actions'
import TodoList from '../components/TodoList'
import { VisibilityFilters } from '../actions'
const getVisibleTodos = (todos, filter) => {
switch (filter) {
case VisibilityFilters.SHOW_ALL:
return todos
case VisibilityFilters.SHOW_COMPLETED:
return todos.filter(t => t.completed)
case VisibilityFilters.SHOW_ACTIVE:
return todos.filter(t => !t.completed)
default:
throw new Error('Unknown filter: ' + filter)
}
}
const mapStateToProps = state => ({
todos: getVisibleTodos(state.todos, state.visibilityFilter)
})
const mapDispatchToProps = dispatch => ({
toggleTodo: id => dispatch(toggleTodo(id))
})
export default connect(
mapStateToProps,
mapDispatchToProps
)(TodoList)