<body>
Below is a custom element.
<test-element>
</test-element>
<undefined-test-element>
Hidden because undefined-test-element is not defined.
</undefined-test-element>
<b>Hidden with adopted stylesheet on document</b>
<p class='my-paragraph' is="my-paragraph"></p>
<p class='undefined-paragraph' is="undefined-paragraph">
This is an undefined built-in custom element
</p>
<script>
class MyParagraph extends HTMLParagraphElement {
constructor() {
super();
const testContents = document.getElementById('test-contents');
const shadowRoot = this.attachShadow({mode: 'open'});
shadowRoot.innerHTML = `This is a defined built-in custom element`;
}
}
customElements.define('my-paragraph', MyParagraph, { extends: "p" });
class TestElement extends HTMLElement {
constructor() {
super();
const testContents = document.getElementById('test-contents');
const shadowRoot = this.attachShadow({mode: 'open'});
const sheet = new CSSStyleSheet();
sheet.replaceSync("a { display: none; }");
shadowRoot.adoptedStyleSheets = [sheet];
shadowRoot.innerHTML = `
<div>
Inside an Autonomous Custom Element
<a>Hidden with adopted stylesheet on shadowRoot</a>
<i>Hidden with stylesheet on shadowRoot</i>
</div>
<style>
/*This will be overridden by the adopted stylesheet.*/
a { display: block; }
i { display: none; }
</style>
`;
}
}
customElements.define('test-element', TestElement);
const sheet = new CSSStyleSheet();
sheet.replaceSync("b { display: none; }");
document.adoptedStyleSheets = [sheet];
</script>
</body>
<style>
test-element:not(:defined) {
display: none;
}
undefined-test-element:not(:defined) {
display: none;
}
p.my-paragraph:not(:defined) {
display: none;
}
trigger */
p.undefined-paragraph:defined {
display: none;
}
b { display: block; }
</style>
