一周一个小demo — vue.js实现备忘录功能
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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‘)
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