[Vue] 15.Vue中的组件：组件传值及传值校验

一、父组件传值给子组件

父组件通过属性将值传给子组件，子组件通过props接收传过来的值：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>15</title>
    <script src="https://unpkg.com/vue@next"></script>
</head>
<body>
    <div id="root"></div>
    <script>
        const app = Vue.createApp({
            template: `<div><test content="hello world"/></div>`
        });
        app.component('test', {
            props: ['content'],
            template: `<div>{{content}}</div>`
        })
        const vm = app.mount('#root')
    </script> 
</body>
</html>

在这里插入图片描述
2. 父组件若要传递number类型的数据给子组件，可传动态参数，即传一个变量

<script>
        const app = Vue.createApp({
            data() {
                return {num: 123}
            },
            template: `<div><test :content="num"/></div>`
        });
        app.component('test', {
            props: ['content'],
            template: `<div>{{typeof content}}</div>`
        })
        const vm = app.mount('#root')
    </script>

二、子组件校验父组件传过来的数据

若子组件想接收字符串，此时验证父组件传过来的值是不是字符串
通过props: { content: String },
来定义想要接收的值的类型，如果不是指定类型，控制台中会有提示

<script>
        const app = Vue.createApp({
            data() {
                return {num: 123}
            },
            template: `<div><test :content="num"/></div>`
        });
        app.component('test', {
            props: {
                content: String
            },
            template: `<div>{{typeof content}}</div>`
        })
        const vm = app.mount('#root')
    </script>

若要要求必须让父组件传值过来，同时还可定义默认值，可按如下写：

<script>
        const app = Vue.createApp({
            data() {
                return {num: 123}
            },
            template: `<div><test :content="num"/></div>`
        });
        app.component('test', {
            props: {
                content: {
                    type:Number,
                    required: true,
                    default: 789
                }
            },
            template: `<div>{{typeof content}}</div>`
        })
        const vm = app.mount('#root')
    </script>

规定子组件接收什么样的数据：validator (若不符合，则在控制台中会有log)

<script>
        const app = Vue.createApp({
            data() {
                return {num: 123}
            },
            template: `<div><test :content="num"/></div>`
        });
        app.component('test', {
            props: {
                content: {
                    type:Number,
                    validator: function(value) {
                        return value < 1000
                    },
                    required: true,
                    default: 789
                }
            },
            template: `<div>{{typeof content}}</div>`
        })
        const vm = app.mount('#root')
    </script>