我遇到过一个问题，即web组件中的插槽实现没有按预期运行。我对Web组件，自定义元素和插槽的理解是，在插槽中呈现的元素应该从文档而不是Shadow DOM继承它们的样式，但是插槽中的元素实际上被添加到Shadow DOM中，因此忽略了全局样式。我创建了以下示例来说明我遇到的问题。
这是一个使用cli（--target wc --name shared-ui ./src/components/*.vue）编译为Web组件的Vue应用程序
<template>
<div :class="[$style.collapsableComponent]">
<div :class="[$style.collapsableHeader]" @click="onHeaderClick" :title="title">
<span>{{ title }}</span>
</div>
<div :class="[$style.collapsableBody]" v-if="expanded">
<slot name="body-content"></slot>
</div>
</div>
</template>
<script lang="ts">
import { Vue, Component, Prop } from 'vue-property-decorator'
@Component({})
export default class CollapsableComponent extends Vue {
@Prop({ default: "" })
title!: string;
@Prop({default: false})
startExpanded!: boolean;
private expanded: boolean = false;
constructor() {
super();
this.expanded = this.startExpanded;
}
get isVisible(): boolean {
return this.expanded;
}
onHeaderClick(): void {
this.toggle();
}
public toggle(expand?: boolean): void {
if(expand === undefined) {
this.expanded = !this.expanded;
}
else {
this.expanded = expand;
}
this.$emit(this.expanded? 'expand' : 'collapse');
}
public expand() {
this.expanded = true;
}
public collapse() {
this.expanded = false;
}
}
</script>
<style module>
:host {
display: block;
}
.collapsableComponent {
background-color: white;
}
.collapsableHeader {
border: 1px solid grey;
background: grey;
height: 35px;
color: black;
border-radius: 15px 15px 0 0;
text-align: left;
font-weight: bold;
line-height: 35px;
font-size: 0.9rem;
padding-left: 1em;
}
.collapsableBody {
border: 1px solid black;
border-top: 0;
border-radius: 0 0 10px 10px;
padding: 1em;
}
</style>
这是一个使用标准脚本包含文件导入shared-ui Web组件的vue应用程序。
App.vue<template>
<div id="app">
<shared-ui title="Test">
<span class="testClass" slot="body-content">
Here is some text
</span>
</shared-ui>
</div>
</template>
<script lang="ts">
import 'vue'
import { Component, Vue } from 'vue-property-decorator';
@Component({ })
export default class App extends Vue {
}
</script>
<style lang="scss">
#app {
font-family: 'Avenir', Helvetica, Arial, sans-serif;
-webkit-font-smoothing: antialiased;
-moz-osx-font-smoothing: grayscale;
text-align: center;
color: #2c3e50;
margin-top: 60px;
}
.testClass{
color: red;
}
</style>
import Vue from "vue";
import App from "./App.vue";
Vue.config.productionTip = false;
// I needed to do this so the web component could reference Vue
(window as any).Vue = Vue;
new Vue({
render: h => h(App),
}).$mount('#app');
在这个例子中，我希望容器内的内容具有红色文本，但是因为Vue将元素克隆到Shadow DOM中，所以忽略.testClass样式并且文本用黑色填充呈现。
如何将.testClass应用于我的Web组件内部的元素？
好的，所以我设法找到了一个使用本机插槽的解决方法，并将子组件正确地呈现在DOM中的正确位置。
在挂载的事件中连接下一个tick，用新插槽替换插槽容器的innerHtml。您可以获得花哨的功能并为命名插槽做一些很酷的替换，但这应该足以说明解决方法。
这是一个使用cli（--target wc --name shared-ui ./src/components/*.vue）编译为Web组件的Vue应用程序
<template>
<div :class="[$style.collapsableComponent]">
<div :class="[$style.collapsableHeader]" @click="onHeaderClick" :title="title">
<span>{{ title }}</span>
</div>
<div ref="slotContainer" :class="[$style.collapsableBody]" v-if="expanded">
<slot></slot>
</div>
</div>
</template>
<script lang="ts">
import { Vue, Component, Prop } from 'vue-property-decorator'
@Component({})
export default class CollapsableComponent extends Vue {
@Prop({ default: "" })
title!: string;
@Prop({default: false})
startExpanded!: boolean;
private expanded: boolean = false;
constructor() {
super();
this.expanded = this.startExpanded;
}
get isVisible(): boolean {
return this.expanded;
}
onHeaderClick(): void {
this.toggle();
}
//This is where the magic is wired up
mounted(): void {
this.$nextTick().then(this.fixSlot.bind(this));
}
// This is where the magic happens
fixSlot(): void {
// remove all the innerHTML that vue has place where the slot should be
this.$refs.slotContainer.innerHTML = '';
// replace it with a new slot, if you are using named slot you can just add attributes to the slot
this.$refs.slotContainer.append(document.createElement('slot'));
}
public toggle(expand?: boolean): void {
if(expand === undefined) {
this.expanded = !this.expanded;
}
else {
this.expanded = expand;
}
this.$emit(this.expanded? 'expand' : 'collapse');
}
public expand() {
this.expanded = true;
}
public collapse() {
this.expanded = false;
}
}
</script>
<style module>
:host {
display: block;
}
.collapsableComponent {
background-color: white;
}
.collapsableHeader {
border: 1px solid grey;
background: grey;
height: 35px;
color: black;
border-radius: 15px 15px 0 0;
text-align: left;
font-weight: bold;
line-height: 35px;
font-size: 0.9rem;
padding-left: 1em;
}
.collapsableBody {
border: 1px solid black;
border-top: 0;
border-radius: 0 0 10px 10px;
padding: 1em;
}
</style>
这是一个使用标准脚本包含文件导入shared-ui Web组件的vue应用程序。
App.vue<template>
<div id="app">
<shared-ui title="Test">
<span class="testClass" slot="body-content">
Here is some text
</span>
</shared-ui>
</div>
</template>
<script lang="ts">
import 'vue'
import { Component, Vue } from 'vue-property-decorator';
@Component({ })
export default class App extends Vue {
}
</script>
<style lang="scss">
#app {
font-family: 'Avenir', Helvetica, Arial, sans-serif;
-webkit-font-smoothing: antialiased;
-moz-osx-font-smoothing: grayscale;
text-align: center;
color: #2c3e50;
margin-top: 60px;
}
.testClass{
color: red;
}
</style>
import Vue from "vue";
import App from "./App.vue";
Vue.config.productionTip = false;
// I needed to do this so the web component could reference Vue
(window as any).Vue = Vue;
new Vue({
render: h => h(App),
}).$mount('#app');