这个vue实现备忘录的功能demo是K在github上找到的，K觉得这是一个用来对vue.js入门的一个非常简单的demo，所以拿在这里共享一下。
（尊重他人劳动成果，从小事做起~ demo原github地址：https://github.com/vuejs/vue）
一、实现效果
二、代码展示
<!DOCTYPE html>
<html> <head>
<meta charset="UTF-8">
<title>备忘录</title>
<link rel="stylesheet" type="text/css" href="css/index.css" />
<style>[v-cloak] { display: none; }</style>
</head> <body>
<section class="todoapp">
<header class="header">
<h1>todos</h1>
<input class="new-todo"
autofocus autocomplete="off"
placeholder="What needs to be done?"
v-model="newTodo"
@keyup.enter="addTodo">
</header>
<section class="main" v-show="todos.length" v-cloak>
<input class="toggle-all" type="checkbox" v-model="allDone">
<ul class="todo-list">
<li v-for="todo in filteredTodos"
class="todo"
:key="todo.id"
:class="{ completed: todo.completed, editing: todo == editedTodo }">
<div class="view">
<input class="toggle" type="checkbox" v-model="todo.completed">
<label @dblclick="editTodo(todo)">{{ todo.title }}</label>
<button class="destroy" @click="removeTodo(todo)"></button>
</div>
<input class="edit" type="text"
v-model="todo.title"
v-todo-focus="todo == editedTodo"
@blur="doneEdit(todo)"
@keyup.enter="doneEdit(todo)"
@keyup.esc="cancelEdit(todo)">
</li>
</ul>
</section>
<footer class="footer" v-show="todos.length" v-cloak>
<span class="todo-count">
<strong>{{ todos.length }}</strong> {{ remaining | pluralize }} left
</span>
<ul class="filters">
<li><a href="#/all" :class="{ selected: visibility == 'all' }">All</a></li>
<li><a href="#/active" :class="{ selected: visibility == 'active' }">Active</a></li>
<li><a href="#/completed" :class="{ selected: visibility == 'completed' }">Completed</a></li>
</ul>
<button class="clear-completed" @click="removeCompleted" v-show="todos.length > remaining">
Clear completed
</button>
</footer>
</section>
<footer class="info">
<p>双击编辑一条备忘录</p>
</footer> </body> <script language="JavaScript" src="js/director.js"></script>
<script language="JavaScript" src="js/vue.js"></script>
<script language="JavaScript" src="js/index_vue.js"></script> </html>
// 本地缓存设置
// 防止页面关闭后，数据全部丢失的问题
var STORAGE_KEY = 'todos-vuejs-2.0'
var todoStorage = { // 获取本地存储中的内容
fetch:function(){
// JSON.parse()解析一个json字符串
// localStorage.getItem 从本地存储中获取STORAGE_KEY字段的值
var todos = JSON.parse(localStorage.getItem(STORAGE_KEY)||'[]');
// foreach遍历todos，两个参数分别为遍历出的每一个子单元及对应的索引
todos.forEach(function(todo,index){
todo.id = index;
})
todoStorage.uid = todos.length;
return todos;
}, // 保存时将内容写进本地存储
save:function(todos){
// localStorage.setItem 将todos转化成字符串存入本地存储，键名为STORAGE_KEY
localStorage.setItem(STORAGE_KEY,JSON.stringify(todos))
} } // 可视化状态过滤设置
// 包括全选（all）、选择未完成（active）、选择已完成（completed）
var filters = {
all:function(todos){
return todos;
}, // filter() 方法创建一个新的数组，新数组中的元素是通过检查指定数组中符合条件的所有元素。
active:function(todos){
return todos.filter(function(todo){
return !todo.completed;
})
}, completed:function(todos){
return todos.filter(function(todo){
return todo.completed;
})
}
} // vue实例化
var app = new Vue({ // data 参数设置
data:{
todos:todoStorage.fetch(),
newTodo:'',
editedTodo:null,
visibility:'all'
}, // watch 监视todos在本地储存中的变化
watch:{
todos:{
handler:function(todos){
todoStorage.save(todos)
},
deep:true
}
}, // computed 检测数据发生变动时执行函数
computed:{ filteredTodos:function(){
return filters[this.visibility](this.todos)
}, remaining:function(){
return filters.active(this.todos).length
}, allDone:{
get:function(){
return this.remaining === 0
}, set:function(value){
this.todos.forEach(function(todo){
todo.completed = value
})
} }
}, // methods 方法设置
methods:{
addTodo:function(){
var value = this.newTodo && this.newTodo.trim()
if(!value){
return;
}
this.todos.push({
id:todoStorage.uid++,
title:value,
completed:false
})
this.newTodo = ''
}, removeTodo:function(todo){
this.todos.splice(this.todos.indexOf(todo),1)
}, editTodo:function(todo){
this.beforeEditCache = todo.title;
this.editedTodo = todo
}, doneEdit:function(todo){
if(!this.editedTodo){
return;
};
this.editedTodo = null;
todo.title = todo.title.trim()
if(!todo.title){
this.removeTodo(todo)
}
}, cancelEdit:function(todo){
this.editedTodo = null;
todo.title = this.beforeEditCache
}, removeCompleted:function(){
this.todos = filters.active(this.todos)
}
}, directives:{
'todo-focus':function(el,binding){
if(binding.value){
el.focus()
}
}
}
}) // hashchange URL的片段标识符更改触发
function onHashChange(){
var visbility = window.location.hash.replace(/#\/?/, '');
if(filters[visbility]){
app.visibility = visbility
}else{
window.location.hash = '';
app.visbility = 'all'
}
} window.addEventListener('hashchange',onHashChange)
onHashChange() // mount 手动挂载
app.$mount('.todoapp')