What is lit?
The lit npm package is a simple and fast library for building web components and web applications. It allows developers to create reusable, encapsulated, and interactive elements using modern JavaScript and Web Component standards. Lit is designed to be lightweight and efficient, focusing on speed and minimal overhead.
What are lit's main functionalities?
Creating Web Components
This feature allows developers to create custom web components using the LitElement base class. The example demonstrates defining a new element with a simple style and rendering method.
import { LitElement, html, css } from 'lit';
class MyElement extends LitElement {
static styles = css`p { color: blue; }`;
render() {
return html`<p>Hello, world!</p>`;
}
}
customElements.define('my-element', MyElement);
Reactive Properties
This feature showcases Lit's reactive property system. The example includes a counter component that updates its display whenever the 'count' property changes.
import { LitElement, html, css, property } from 'lit';
class MyCounter extends LitElement {
@property({ type: Number }) count = 0;
render() {
return html`
<button @click=${this._increment}>Increment</button>
<span>${this.count}</span>
`;
}
_increment() {
this.count++;
}
}
customElements.define('my-counter', MyCounter);
Styling Components
This feature demonstrates how to apply CSS styles to a Lit component. The example shows defining styles for the component itself and its internal elements.
import { LitElement, html, css } from 'lit';
class StyledElement extends LitElement {
static styles = css`
:host {
display: block;
border: 1px solid black;
padding: 16px;
max-width: 200px;
}
.highlight {
color: red;
}
`;
render() {
return html`<div class='highlight'>Styled Content</div>`;
}
}
customElements.define('styled-element', StyledElement);
Other packages similar to lit
react
React is a popular library for building user interfaces. It focuses on a component-based architecture similar to Lit but uses a virtual DOM for updates, which differs from Lit's direct DOM manipulation approach.
vue
Vue is a progressive framework for building UIs. Like Lit, it emphasizes component-based development and reactivity. However, Vue offers a more comprehensive framework experience with options for routing and state management.
svelte
Svelte is a compiler that generates efficient JavaScript code from component declarations. Unlike Lit, which runs in the browser, Svelte shifts much of the work to compile time, resulting in smaller bundles and faster runtime execution.
Simple. Fast. Web Components.
Lit is a simple library for building fast, lightweight web components.
At Lit's core is a boilerplate-killing component base class that provides reactive state, scoped styles, and a declarative template system that's tiny, fast and expressive.
Documentation
See the full documentation for Lit at lit.dev
About this release
This is a stable release of Lit 2.0. If upgrading from previous versions of lit-element
or lit-html
, please see the Upgrade Guide for a step-by-step guide on upgrading.
Overview
Lit provides developers with just the right tools to build fast web components:
- A fast declarative HTML template system
- Reactive property declarations
- A customizable reactive update lifecycle
- Easy to use scoped CSS styling
Lit builds on top of standard web components, and makes them easier to write:
import {LitElement, html, css} from 'lit';
import {customElement, property} from 'lit/decorators.js';
@customElement('my-element')
export class MyElement extends LitElement {
static styles = css`
span {
color: green;
}
`;
@property()
mood = 'great';
render() {
return html`Web Components are <span>${this.mood}</span>!`;
}
}
Once you've defined your component, you can use it anywhere you use HTML:
<my-element mood="awesome"></my-element>
Contributing
Please see CONTRIBUTING.md.