vuejs 从子组件更新父数据 [英] vuejs update parent data from child component

问题描述

我开始使用 vuejs (2.0).我构建了一个简单的页面，其中包含一个组件.该页面有一个包含数据的 Vue 实例.在该页面上，我注册并将组件添加到 html.该组件有一个 input[type=text].我希望该值反映在父级(主 Vue 实例)上.

如何正确更新组件的父数据?从父级传递绑定道具并不好，并向控制台抛出一些警告.他们的文档中有一些东西，但它不起作用.

解决方案

双向绑定在 Vue 2.0 中已被弃用，转而使用更加事件驱动的架构.一般来说，一个孩子不应该改变它的道具.相反，它应该 $emit 事件并让父响应这些事件.

在您的特定情况下，您可以使用带有 v-model 的自定义组件.这是一种特殊的语法，允许接近双向绑定，但实际上是上述事件驱动架构的简写.你可以在这里阅读 -> https://vuejs.org/v2/guide/components.html#Form-Input-Components-using-Custom-Events.

这是一个简单的例子:

Vue.component('child', {模板:'#child'，//孩子有一个名为'value'的道具.v-model 会自动绑定到这个 prop道具:['价值']，方法: {更新值:函数(值){this.$emit('input', value);}}});新的 Vue({el: '#app',数据: {父值:'你好'}});

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.13/vue.js"></脚本><div id="应用程序"><p>父值:{{parentValue}}</p><child v-model="parentValue"></child>

<模板 id="子"><input type="text" v-bind:value="value" v-on:input="updateValue($event.target.value)"></template>

<小时>

文档说明

<custom-input v-bind:value="something" v-on:input="something = arguments[0]"></custom-input>

相当于

<custom-input v-model="something"></custom-input>

这就是为什么child上的prop需要被命名为value，以及为什么child需要$emit一个名为input的事件.

I'm starting to play with vuejs (2.0). I built a simple page with one component in it. The page has one Vue instance with data. On that page I registered and added the component to html. The component has one input[type=text]. I want that value to reflect on the parent (main Vue instance).

How do I correctly update the component's parent data? Passing a bound prop from the parent is not good and throws some warnings to the console. They have something in their doc but it is not working.

解决方案

Two-way binding has been deprecated in Vue 2.0 in favor of using a more event-driven architecture. In general, a child should not mutate its props. Rather, it should $emit events and let the parent respond to those events.

In your specific case, you could use a custom component with v-model. This is a special syntax which allows for something close to two-way binding, but is actually a shorthand for the event-driven architecture described above. You can read about it here -> https://vuejs.org/v2/guide/components.html#Form-Input-Components-using-Custom-Events.

Here's a simple example:

Vue.component('child', {
  template: '#child',
  
  //The child has a prop named 'value'. v-model will automatically bind to this prop
  props: ['value'],
  methods: {
    updateValue: function (value) {
      this.$emit('input', value);
    }
  }
});

new Vue({
  el: '#app',
  data: {
    parentValue: 'hello'
  }
});

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.13/vue.js"></script>

<div id="app">
  <p>Parent value: {{parentValue}}</p>
  <child v-model="parentValue"></child>
</div>

<template id="child">
   <input type="text" v-bind:value="value" v-on:input="updateValue($event.target.value)">
</template>

---

The docs state that

<custom-input v-bind:value="something" v-on:input="something = arguments[0]"></custom-input>

is equivalent to

<custom-input v-model="something"></custom-input>

That is why the prop on the child needs to be named value, and why the child needs to $emit an event named input.

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