@happy-dom/server-rendering NPM

:warning: This package is deprecated. Happy DOM now supports Declarative Shadow DOM which can be used for server-side rendering of web components instead. :warning:

About

Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. It includes many web standards from WHATWG DOM and HTML.

The goal of Happy DOM is to emulate enough of a web browser to be useful for testing, scraping web sites and server-side rendering.

Happy DOM focuses heavily on performance and can be used as an alternative to JSDOM.

This package makes it easier to setup servering side rendering of web components by handling the setup of the Node VM Context for you.

DOM Features

Custom Elements (Web Components)
Shadow Root (Shadow DOM)
Declarative Shadow DOM
Mutation Observer
Tree Walker
Fetch

And much more..

Works With

Installation

npm install @happy-dom/server-rendering

Usage

import { HappyDOMContext } from '@happy-dom/server-rendering';
import { Script } from 'vm';

const context = new HappyDOMContext();
const result = await context.render({
    url: 'http://localhost:8080',
    evaluateScripts: true,
    html: `
        <html>
            <head>
                <title>Test page</title>
            </head>
            <body>
                <div class="container">
                    <!–– Content will be added here -->
                </div>
            </body>
        </html>
    `,
    // Optional scripts
    scripts: [
        new Script(`
            const element = document.createElement('div');
            const container = document.querySelector('.container');
            element.innerHTML = 'Test';
            container.appendChild(element);
        `)
    ],
    // Optional custom element settings
    customElements: {
        // Converts custom-elements to normal elements
        openShadowRoots: true,
        // Extracts CSS from shadow roots
        extractCSS: true,
        // Scopes extracted CSS
        scopeCSS: true,
        // Adds CSS to head
        addCSSToHead: true
    }
});

// Outputs: <html><head><title>Test page</title></head><body><div class="container"><div>Test</div></div></body></html>
console.log(result);

Known Issues

The functionality of CSS scoping has not been completed, so you may encounter some problem where CSS is not scoped correctly.

Performance

Operation	JSDOM	Happy DOM
Import / Require	333 ms	45 ms
Parse HTML	256 ms	26 ms
Serialize HTML	65 ms	8 ms
Render custom element	214 ms	19 ms
querySelectorAll('tagname')	4.9 ms	0.7 ms
querySelectorAll('.class')	6.4 ms	3.7 ms
querySelectorAll('attribute')	4.0 ms	1.7 ms
querySelectorAll('class~="name"')	5.5 ms	2.9 ms
querySelectorAll(':nth-child(2n+1)')	10.4 ms	3.8 ms