如何让导入的CSS字体/图标对阴影dom中的元素产生影响? [英] How to let imported css font / icons have effects on elements in the shadow dom?

问题描述

说，如果我想使用shadow dom创建自定义元素.模板中的某些元素具有在链接的CSS文件中指定的类名称.现在，我想让CSS规则对元素产生影响.但是由于阴影dom样式的边界，我无法实现这一目标.

Say if I want to create a custom element using shadow dom. Some elements in the template have class names specified in the linked css file. Now I want to let the css rules have effects on the elements. But I can't achieve that because of the shadow dom style boundary.

<link rel="stylesheet" type="text/css"
href="https://maxcdn.bootstrapcdn.com/font-awesome/4.5.0/css/font-awesome.min.css">
<template id="blog-header">
<header>
    <h1>DreamLine</h1>
    <nav>
        <ul>
            <li><a href="#0">Tour</a></li>
            <li><a href="#0">Blog</a></li>
            <li><a href="#0">Contact</a></li>
            <li><a href="#0">Error</a></li>
            <li><a href="#0"><i class="fa fa-search"></i>Search</a></li>
        </ul>
    </nav>
</header>
</template>
<script type="text/javascript">
var importDoc = document.currentScript.ownerDocument;
var proto = Object.create(HTMLElement.prototype, {
    createdCallback: {
        value: function () {
            var t = importDoc.querySelector("#blog-header");
            var clone = document.importNode(t.content, true);
            this.createShadowRoot().appendChild(clone);
        }
    }
});
document.registerElement("blog-header", {
    prototype: proto
});
</script>

您看到，fa-search是在字体超赞的CSS文件中定义的类，如何设置<i>元素的样式?

You see, fa-search is a class defined in the font-awesome css file, how can I style the <i> element?

推荐答案

要在Shadow DOM中使用导入的字体(例如 FontAwesome )，您应该:

To use an imported font (e.g., FontAwesome) in a Shadow DOM, you should:

1°声明字体

首先，在主文档中包含<link rel="stylesheet">元素.它将声明一个@font-face CSS规则，该规则将使字体可用于文档中的所有文本.

First, include the <link rel="stylesheet"> element in the main document. It will declare a @font-face CSS rule that will make the font available for all the text in the document.

2°导入样式表

然后，在<template>节点中使用@import url CSS规则导入同一文件，以使.fa-*类选择器可从Shadow DOM中使用:

Then, import the same file with an @import url CSS rule in the <template> node to make the .fa-* classes selectors available from the Shadow DOM :

<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.7.1/css/all.css" integrity="sha384-fnmOCqbTlWIlj8LyTjo7mOUStjsKC4pOpQbqyi7RrhN7udi9RwhKkMHpvLbHG9Sr" crossorigin="anonymous">

<template id="blog-header">
  <style>
    @import url("https://use.fontawesome.com/releases/v5.7.1/css/all.css")
  </style>
  <header>
    <h1>DreamLine</h1>
    //...
  </header>
</template>

var importDoc = document.currentScript.ownerDocument;
var proto = Object.create(HTMLElement.prototype, {
	createdCallback: {
		value: function() {
			var t = importDoc.querySelector("#blog-header");
			var clone = document.importNode(t.content, true);
			this.createShadowRoot().appendChild(clone);
		}
	}
});
document.registerElement("blog-header", {prototype: proto});

/* 
@font-face {
    font-family: "FontAwesome";
    src: url("https://maxcdn.bootstrapcdn.com/font-awesome/4.5.0/css/font-awesome-webfont.woff2?v=4.5.0") format('woff2');
  }
*/

<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.7.1/css/all.css" integrity="sha384-fnmOCqbTlWIlj8LyTjo7mOUStjsKC4pOpQbqyi7RrhN7udi9RwhKkMHpvLbHG9Sr" crossorigin="anonymous">

<template id="blog-header">
  <style>
    @import url("https://use.fontawesome.com/releases/v5.7.1/css/all.css")
  </style>
	<header>
		<h1>DreamLine</h1>
		<nav>
			<ul>
				<li><a href="#0">Tour</a></li>
				<li><a href="#0">Blog</a></li>
				<li><a href="#0">Contact</a></li>
				<li><a href="#0">Error</a></li>
				<li><a href="#0"><i class="fa fa-search"></i>Search</a></li>
			</ul>
		</nav>
	</header>
</template>

<blog-header></blog-header>

更新2019

现在，您可以在Shadow DOM中使用<link rel="stylesheet">代替@import url().

Now you can use <link rel="stylesheet"> instead of @import url() inside a Shadow DOM.

这篇关于如何让导入的CSS字体/图标对阴影dom中的元素产生影响?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！