2019-07-10留言板组件父子通信

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <link rel="stylesheet" href="./bootstrap.css">
    <title>Document</title>
</head>
<style>
    #app {
        width: 700px;
        margin: 0 auto;
    }
</style>

<body>
    <div id="app">
        <msg-title></msg-title>
    </div>
</body>

<script src="../vue.js"></script>
<script src="../axios.js"></script>
<script>
    //创建标题组件
    const msgTitle = {
        template: `
        <div class="panel panel-primary">
            <div class="panel-heading">
                <h3 class="panel-title">留言板</h3>
            </div>
            <msg-input></msg-input>
        </div>
        `
    }
    //创建输入框组件
    const msgInput = {
        template: `
            <div class="panel-body">
                <input type="text" class="form-control" placeholder="请输入姓名" v-model="addContents.user">
                <br>
                <textarea class="form-control" rows="5" placeholder="请输入留言内容" v-model="addContents.content"></textarea>
                <br>
                <button type="button" class="btn btn-primary pull-right" @click="submit">提交</button>
                <br/><br/>
                <msg-list :contents="contents"></msg-list>
                <!--:contents="contents"把content这个动态的数据传送给子组件-->
            </div>
        `,
        data() {
            return {
                addContents:
                {
                    user: "",
                    content: ""
                }
                ,
                contents: []

            }
        },
        methods: {
            submit() {
                this.contents.unshift(Object.assign({}, this.addContents));
                this.addContents.content = '';
            }
        }
    }
    //创建留言列表组件
    const msgList = {
        template: `
            <ul class="list-group">
                <template v-if="contents.length">
                    <li class="list-group-item" v-for="(childContent,index) in childContents">
                        <button @click="del(index)" type="button" class="close" aria-label="Close"><span
                                aria-hidden="true">&times;</span></button>
                        <h5 class="list-group-item-heading" style="font-weight:700">{{childContent.user}}:</h5>
                        <p class="list-group-item-text">{{childContent.content}}</p>
                    </li>
                </template>
                <li class="list-group-item" v-else>
                    <h5 class="list-group-item-heading" style="font-weight:700">暂无留言</h5>
                </li>
            </ul>
        `,
        props: ["contents"],//自组件中用props接收数据，但是子组件无法修改这个数据
        data(){
            return{
                childContents:this.contents//所以子组件把这个数据拷贝一份留给自己进行操作
            }
        },
        methods:{                                                          
            del(index){
                this.childContents.splice(index,1)
            }
        }
    }

    //注册组件
    Vue.component("msgTitle", msgTitle);
    Vue.component("msgInput", msgInput);
    Vue.component("msgList", msgList);
    const app = new Vue({
        el: "#app",
    })


</script>

</html>