redux使用流程理解
redux/actions.js
/*
* action 类型
*/
export const ADD_TODO = 'ADD_TODO';
export const TOGGLE_TODO = 'TOGGLE_TODO'
export const SET_VISIBILITY_FILTER = 'SET_VISIBILITY_FILTER'
/*
* 其它的常量
*/
export const VisibilityFilters = {
SHOW_ALL: 'SHOW_ALL',
SHOW_COMPLETED: 'SHOW_COMPLETED',
SHOW_ACTIVE: 'SHOW_ACTIVE'
}
/*
* action 创建函数
*/
export function addTodo(text) {
return { type: ADD_TODO, text }
}
export function toggleTodo(index) {
return { type: TOGGLE_TODO, index }
}
export function setVisibilityFilter(filter) {
return { type: SET_VISIBILITY_FILTER, filter }
}
redux/reduces.js
import { combineReducers } from 'redux'
import {
ADD_TODO,
TOGGLE_TODO,
SET_VISIBILITY_FILTER,
VisibilityFilters
} from './actions'
const { SHOW_ALL } = VisibilityFilters
function visibilityFilter(state = SHOW_ALL, action) {
switch (action.type) {
case SET_VISIBILITY_FILTER:
return action.filter
default:
return state
}
}
function todos(state = [{text:'majiang',completed:true}], action) {
switch (action.type) {
case ADD_TODO:
return [
...state,//默认数据
{
text: action.text,
completed: false
}
]
case TOGGLE_TODO:
return state.map((todo, index) => {
if (index === action.index) {
return Object.assign({}, todo, {
completed: !todo.completed
})
}
return todo
})
default:
return state
}
}
const todoApp = combineReducers({
visibilityFilter,
todos
})
export default todoApp
index.js
import { createStore } from 'redux'
import todoApp from './redux/reducers'
import {
addTodo,
toggleTodo,
setVisibilityFilter,
VisibilityFilters
} from './redux/actions'
let store = createStore(todoApp)
// 打印初始状态
console.log(store.getState())
// 每次 state 更新时,打印日志
// 注意 subscribe() 返回一个函数用来注销监听器
const unsubscribe = store.subscribe(() =>
console.log(store.getState())
)
// 发起一系列 action
store.dispatch(addTodo('Learn about actions'))
store.dispatch(addTodo('Learn about reducers'))
store.dispatch(addTodo('Learn about store'))
store.dispatch(toggleTodo(0))
store.dispatch(toggleTodo(1))
store.dispatch(setVisibilityFilter(VisibilityFilters.SHOW_COMPLETED))
// 停止监听 state 更新
unsubscribe();
参考:
https://github.com/kenberkeley/redux-simple-tutorial
欢迎关注小程序,感谢您的支持!
lucas
2021年11月24日 下午2:38
我找了好多redux教程例子,就你这个让我学习到了,其他真的就是狗屎
MJ
2022年2月20日 下午3:04
感谢抬爱