vue2.0

父传子：Props
子传父：子：$emit(eventName) 父$on(eventName)
父访问子：ref
非父子组件通信 :https://vuefe.cn/guide/components.html#非父子组件通信
vue2.0 移除：1.$dispatch() 2.$broadcast() 3.events

vue1.0

<template><div id="app"><p>{{title}}</p><p v-text="title"></p><p v-text="title2"></p><p v-html="title2"></p></div>
</template>
<script>
export default {data () {return {title: 'this is a title!',title2: '<span>?<span> this is a title!'}}
}
</script>

• {{title}}和v-text="title"等同
• export default最后生成 new vue({ 参数})

• 新的ES6写法等同于旧的写法

  //新的ES6
  data () {
  return {title: 'this is a title!'
  }
  }

  //旧的写法
  data: function (){
  return {title: 'this is a title!'
  }
  }

• v-html 解析渲染html标签

v-for 及v-bind控制class、v-on绑定事件、v-model双向绑定

<template><div id="app"><p>{{title}}</p><!-- <p v-text="title"></p> --><!-- <p v-text="title2"></p> --><!-- <p v-html="title2"></p> --><input v-model="newItem" v-on:keyup.enter="addNew"><ul><li v-for = "item in items" v-bind:class="{finished: item.isFinished}" v-on:click="toggleFinished(item)">{{item.label}}</li></ul></div>
</template>
<script>
import Store from './store'
export default {data () {return {title: 'this is a todolist!',title2: '<span>?<span> this is a todolist!',items: Store.fetch(),newItem: ''}},watch: {items: {handler (items) {Store.save(items)},deep: true}},methods: {toggleFinished (item) {item.isFinished = !item.isFinished},addNew () {this.items.push({label: this.newItem,isFinished: false})this.newItem = ''}}
}
</script><style>
.finished{text-decoration: underline;
}html {height: 100%;
}body {display: flex;align-items: center;justify-content: center;height: 100%;
}#app {color: #2c3e50;margin-top: -100px;max-width: 600px;font-family: Source Sans Pro, Helvetica, sans-serif;text-align: center;
}#app a {color: #42b983;text-decoration: none;
}.logo {width: 100px;height: 100px
}
</style>

store.js

const STORAGE_KEY = 'todos-vuejs'
export default {fetch () {return JSON.parse(window.localStorage.getItem(STORAGE_KEY) || '[]')},save (items) {window.localStorage.setItem(STORAGE_KEY, JSON.stringify(items))}
}

• v-bind:class简写:class
• v-on:click简写@click
• v-on:keyup.enter简写@keyup.enter 回车keyup事件
• v-model 双向绑定

JSON.parse()和JSON.stringify()

• parse用于从一个字符串中解析出json 对象。例如
  var str='{"name":"cpf","age":"23"}'

经 JSON.parse(str) 得到：

Object: age:"23"name:"cpf"_proto_:Object

ps:单引号写在{}外，每个属性都必须双引号，否则会抛出异常

• stringify用于从一个对象解析出字符串，例如

var a={a:1,b:2}

经 JSON.stringify(a)得到：

“{“a”:1,"b":2}”

自定义事件

• 使用 $on() 监听事件；

• 使用 $emit()在它上面触发事件；

• 使用 $dispatch()派发事件，事件沿着父链冒泡；

• 使用 $broadcast()广播事件，事件向下传导给所有的后代。

父组件向子组件传递

1、采用props

父组件

<component-a msgfromfather='you die!!!!'></component-a>

子组件

<template><div class="hello"><h1>{{ msgfromfather }}</h1><button v-on:click="onClickMe">click!</button></div>
</template><script>
export default {data () {return {}},props: ['msgfromfather'],methods: {onClickMe () {console.log(this.msgfromfather)}}
}
</script>
<style scoped>
h1 {color: #42b983;
}
</style>

• props监听父组件传递过来的信息
• 传递过来后，可直接引用，就如已经传递过来数据塞到data

2、使用event,$broadcast()从父组件传递消息下去

父组件

<template>
<button v-on:click="talkToMyBoy('be a good boy')">talkToMyBoy</button></div>
</template>
<script>
import Store from './store'
import ComponentA from './components/componentA'
export default {components: {ComponentA},methods: {talkToMyBoy (msg) {//console.log(msg);this.$broadcast('onAddnew',msg)}}
}
</script>

子组件

<template><div class="hello"><h1>{{ listentomyfather }}</h1></div>
</template>
<script>
export default {data () {return {listentomyfather: 'Hello from componentA!'}},events: {'onAddnew' (msg) {//console.log(msg)this.listentomyfather = msg}}
}
</script>

子组件向父组件传递

1.子组件$emit()触发，父组件$on()监听

<template><div class="hello"><button v-on:click="onClickMe">telltofather</button></div>
</template><script>
export default {methods: {onClickMe () {this.$emit('child-tell-me-something',this.msg)}}
}
</script>

父组件

<template>
<div id="app">
<p>child tell me: {{childWords}}</p>
<component-a v-on:child-tell-me-something='listenToMyBoy'></component-a>
</div>
</template><script>
import Store from './store'
import ComponentA from './components/componentA'
export default {components: {ComponentA},data () {return {childWords: ''}},methods: {listenToMyBoy (msg) {this.childWords = msg}}
}
</script>

2.不使用v-on,使用event ,子组件$dispatch()，从子组件传递消息上去

子组件

<template><div class="hello"><button v-on:click="onClickMe">talktomyfather</button></div>
</template><script>
export default {methods: {onClickMe () {this.$dispatch('child-tell-me-something',this.msg)}}
}
</script>

父组件

<template><div id="app"><p>child tell me: {{childWords}}</p><component-a></component-a></div>
</template><script>
import Store from './store'
import ComponentA from './components/componentA'
export default {components: {ComponentA},data () {return {childWords: ''}},events: {'child-tell-me-something' (msg) {this.childWords = msg}}
}
</script>