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Vue.js 组件 - 组件间的循环引用示例

写了大大小小不少基于vue的项目,但是基本没用到过组件循环引用的知识。
为了查缺补漏,照着官方文档撸一个DEMO:组件之间的循环引用

本人的运行版本为 vue-cli@2.8.1,启用项目后,将以下 js 文件和 vue 文件放置在相应的目录中运行。

main.js

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import Vue from 'vue'
import App from './App'
new Vue({
el: '#app',
template: '<App/>',
components: { App }
})

main.js 导入 App 组件,并在 components 中注册 App 组件。

App.vue

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<template>
<div id="app">
<li v-for="folder in folders">
<tree-folder v-bind:folder="folder"></tree-folder>
</li>
</div>
</template>
<script>
import TreeFolder from './components/tree-folder'
export default {
data: function () {
return {
folders: [
{
name: 'folder1',
children: [{
name: 'folder1 - folder1',
children: [{
name: 'folder1 - folder1 - folder1'
}]
}, {
name: 'folder1 - folder2',
children: [{
name: 'folder1 - folder2 - folder1'
}, {
name: 'folder1 - folder2 - folder2'
}]
}]
},
{
name: 'folder 2',
children: [{
name: 'folder2 - folder1',
children: [{
name: 'folder2 - folder1 - folder1'
}]
}, {
name: 'folder2 - folder2',
children: [{
name: 'folder2-content1'
}]
}]
},
{
name: 'folder 3',
children: [{
name: 'folder3 - folder1',
children: [{
name: 'folder3 - folder1 - folder1'
}]
}, {
name: 'folder3 - folder2',
children: [{
name: 'folder3-content1'
}]
}]
}
]
}
},
components: {
TreeFolder
}
}
</script>

App 组件导入 TreeFolder 组件,并在 components 中注册 TreeFolder 组件。

components/tree-folder.vue

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<template>
<p>
<span>{{ folder.name }}</span>
<tree-folder-contents :children="folder.children"></tree-folder-contents>
</p>
</template>
<script>
// 官方文档:「在我们的例子中,将 tree-folder 组件做为切入起点。我们知道制造矛盾的是 tree-folder-contents 子组件,所以我们在 tree-folder 组件的生命周期钩子函数 beforeCreate 中去注册 tree-folder-contents 组件」
export default {
props: ['folder'],
data: function () {
return {}
},
beforeCreate: function () {
// 官方文档给出的是require
// this.$options.components.TreeFolderContents = require('./tree-folder-contents.vue')
// 在基于vue-cli@2.8.1按照上面的写法还是会报错
// Failed to mount component: template or render function not defined.
// 所以我们应该改为基于es6的写法异步加载一个组件如下
this.$options.components.TreeFolderContents = () => import('./tree-folder-contents.vue')
}
}
</script>

TreeFolder 组件导入 TreeFolderContents 组件,并在 components 中注册 TreeFolderContents 组件。

components/tree-folder-contents.vue

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<template>
<ul>
<li v-for="child in children">
<tree-folder v-if="child.children" :folder="child"></tree-folder>
<span v-else>{{ child.name }}</span>
</li>
</ul>
</template>
<script>
import TreeFolder from './tree-folder'
export default {
props: ['children'],
components: {
TreeFolder
}
}
</script>

TreeFolderContents 组件又导入 TreeFolder 组件,并在 components 中注册 TreeFolder 组件,产生了循环引用。

参考资料:
1、http://lizhihua.me/2016/12/24/vue/component_circlar-reference/
2、https://cn.vuejs.org/v2/guide/components.html#%E7%BB%84%E4%BB%B6%E9%97%B4%E7%9A%84%E5%BE%AA%E7%8E%AF%E5%BC%95%E7%94%A8
3、https://cn.vuejs.org/v2/guide/components.html#%E5%BC%82%E6%AD%A5%E7%BB%84%E4%BB%B6

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