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Omi - Front End Cross-Frameworks Framework

Merge Web Components, JSX, HTM, Virtual DOM, Functional style and Proxy into one framework with tiny size and high performance. Write components once, using in everywhere, such as Omi, React, Preact, Vue or Angular.

Quick Preview

Pass data through the component tree without having to pass props down manually at every level by store, auto update the view on demand.

import { define, render } from 'omi'

class Store {
  data = {
    count: 1
  }
  sub = () => {
    this.data.count--
  }
  add = () => {
    this.data.count++
  }
}

define('my-counter', _ => (
  <div>
    <button onClick={_.store.sub}>-</button>
    <span>{_.store.data.count}</span>
    <button onClick={_.store.add}>+</button>
  </div>
), {
    use: ['count'], 
    //or using useSelf, useSelf will update self only, exclude children components
    //useSelf: ['count'], 
    css: `span { color: red; }`,
    installed() {
      console.log('installed')
    }
  })

render(<my-counter />, 'body', new Store)

• <my-counter></my-counter> can be used in any framework or no framework, such as document.createElement('my-counter')

Ecosystem of Omi

Base

Project	Description
omi-docs and codepen and wcd demos	Omi official documents
omim	Cross frameworks and themes components.(DOCS & REPL && JOIN US!)
omi-kbone	使用 omi + kbone 多端开发(小程序和Web)的贪吃蛇游戏。
omio	Omi for old browsers with same api(IE8+)
omi-ssr	Server-side rendering(support omio only)
omi-router	Omi official router in 1KB js
omi-cli	Project scaffolding. → Base Templates and → Other Templates
omi-devtools	Browser DevTools extension
omiu	Simple Omi UI
omil	Webpack loader for Omi.js components.(DOCS)
omi-snippets	A beautify VSCode extension for .omi or .eno file, Install now!
obaa or JSONPatcherProxy	Observe or Proxy any object's any change

Snake MVP

Project	Description
omi-snake & → Touch the demo	The Snake-Eating Game Based on MVP Architecture Written by Omi
omi-kbone-snake	omi-kbone 写的 MVP 架构的贪吃蛇小程序
react-snake	The Snake-Eating Game Based on MVP Architecture Written by React

Mini Program(小程序)

Project	Description
react-kbone	直接使用 React 开发小程序或 Web，基于 kbone
preact-kbone	直接使用 Preact 开发小程序或 Web，基于 kbone
omix	极小却精巧的小程序框架
omi-cloud	小程序•云开发
omip	直接使用 Omi 开发小程序或 H5 SPA
mps	原生小程序增强框架(JSX + Less 输出 WXML + WXSS)，也支持 QQ 轻应用
cax	小程序 Canvas 和 SVG 渲染引擎
omi-mp	通过微信小程序开发和生成 Web 单页应用(H5 SPA)
westore	小程序状态管理
comi	小程序代码高亮和 markdown 渲染组件
wx-touch-event	基于 AlloyFinger 改造的小程序手势解决方案

Other

Project	Description
omi-piano	Build piano with Omi and Omi Snippets, Enjoy now!
omi-chart	Simple HTML5 Charts using chart-x tag.
md2site	Static Site Generator with markdown powered by Omio.
omi-30-seconds	Useful Omi snippets that you can understand in 30 seconds.
omi-canvas	Perfect fusion of web components, jsx and canvas.
omi-swiper	Omi + Swiper
omi-vscode	VSCode extension for omi, Install now!
omi-ex	Omi.js extension(TypeScript)
omi-transform	Omi / css3transform integration. Made css3 transform super easy in your Omi project.
omi-finger	Support touch and gesture events in your Omi project.
omi-touch	Smooth scrolling, rotation, pull to refresh and any motion for the web.
omi-native	Render web components to native
omi-i18n	Internationalization solution for omi.js using i18next ecosystem
omi-page	Tiny client-side router by page
omie	Build cross platform desktop apps with Omi.js and Electron.js
omi-cv	Create a front-end engineer curriculum vitae, Get Started!

Why Omi?

• Tiny size and High performance
• Cross frameworks(react, preact, vue, angular), components of omi are pure custom elements
• One framework. Mobile & desktop & mini program
• Stateless View Architecture Design
• Be friendly to custom elements, you can pass false attributes to elements through string '0' or string 'flase', you can pass object attributes to elements through : prefix and Omi.$
• Easy two way binding by extend api
• Supports TypeScript
• Reactive data-binding
• Native tap event support
• Having Cross-frameworks UI components - omim
• Excellent compatibility(IE8+) with omio
• Enhanced CSS, rpx unit support base on 750 screen width
• Compliance with browser trend and API design
• Merge Web Components, JSX and HTM into one framework
• Web Components can also be a data-driven view, UI = fn(data).
• JSX is the best development experience (code intelligent completion and tip) UI Expression with least grammatical noise and it's turing complete(template engine is not, es template string is but grammatical noise is too loud)
• Look at Facebook React vs Web Components，Omi combines their advantages and gives developers the freedom to choose the way they like
• Shadow DOM merges with Virtual DOM, Omi uses both virtual DOM and real Shadow DOM to make view updates more accurate and faster
• Scoped CSS's best solution is Shadow DOM, the community churning out frameworks and libraries for Scoped CSS (using JS or JSON writing styles such as Radium, jsxstyle, react-style; binding to webpack using generated unique className filename-classname-hash, such as CSS Modules, Vue), are hack technologies; and Shadow DOM Style is the perfect solution.
• The original Path Updating store system. Proxy-based automatic accurate update, low power consumption, high degree of freedom, excellent performance, easy integration of requestIdleCallback,It will automatically update UI partially when data is changed

Compare TodoApp by Omi and React, Omi and React rendering DOM structure:

Omi	React	Omio

Omi uses Shadow DOM based style isolation and semantic structure.

Useful Resources

Title Name	Other language	Related
Snake-Eating Game Making with Web Components of Omi and MVP Architecture
Constructable Stylesheets: seamless reusable styles
Web Components specifications
Web Components in a Nutshell
Using Web Components with React in 2019
Using Web Components in React
Styling We Components Using A Shared Style Sheet
Developer Tools support for Web Components in Firefox 63
Develop W3C Web Components with WebAssembly
60FPS Animation In Omi	简体中文 한국어
Render Web Components To Native	简体中文 한국어
Shadow Dom In Depth	简体中文
Part Theme Explainer	求翻译
Web Components MDN	简体中文
Web Components Google
Web Components Org
Web Components: the Right Way
Proxy MDN	简体中文 한국어
CSS Variables	简体中文 한국어
CSS Shadow Parts
Platform HTML5
Using requestIdleCallback	简体中文	A polyfill
The Power Of Web Components	简体中文
ShadowRoot	简体中文

Overview of the Readme

• Ecosystem of Omi
• Useful Resources
• Add Omi in One Minute
• Add Omi in 30 Seconds
• Getting Started
  • Install
  • Project Template
  • Hello Element
  • TodoApp
  • TypeScript Auto Complete
  • Lifecycle
• Debugging
• Browsers Support
• Contributors
• Maintainers
• Thanks
• License

Add Omi in One Minute

This page demonstrates using Omi with no build tooling, directly run in the browser.

• → Online Demo!

<!DOCTYPE html>
<html>

<head>
  <title>Omi demo without transpiler</title>
</head>

<body>
  <script src="https://tencent.github.io/omi/packages/omi/dist/omi.js"></script>
  <script>
    const { define, WeElement, html, render } = Omi

    define('my-counter', class extends WeElement {

      install() {
        this.count = 1
        this.sub = this.sub.bind(this)
        this.add = this.add.bind(this)
      }

      sub() {
        this.count--
        this.update()
      }

      add() {
        this.count++
        this.update()
      }

      render() {
        return html`
            <div>
              <button onClick=${this.sub}>-</button>
              <span>${this.count}</span>
              <button onClick=${this.add}>+</button>
            </div>
            `}
    })

    render(html`<my-counter />`, 'body')
  </script>
</body>

</html>

Using store system

Omi Store provides a way to pass data through the component tree without having to pass props down manually at every level, injected from the root component and shared across all subcomponents. It's very simple to use:

<!DOCTYPE html>
<html>

<head>
  <meta charset="UTF-8" />
  <title>Omi demo without transpiler</title>
</head>

<body>
  <script src="https://tencent.github.io/omi/packages/omi/dist/omi.js"></script>
  <script>
    const { define, WeElement, html, render } = Omi

    define('my-counter', class extends WeElement {
      use() {
        return ['count']
      }
      //or
      //static use = ['count']

      install() {
        this.sub = this.sub.bind(this)
        this.add = this.add.bind(this)
      }

      sub() {
        ////use this.store in any method of any children components
        this.store.data.count--
      }

      add() {
        this.store.data.count++
      }

      render() {
        return html`
          <div>
            <button onClick=${this.sub}>-</button>
            <span>${this.store.data.count}</span>
            <button onClick=${this.add}>+</button>
          </div>
          `}
    })

    //Injection through a third parameter
    render(html`<my-counter />`, 'body', {
      data: {
        count: 1
      }
    })
  </script>

</body>

</html>

You can also use my-counter tag directly in HTML：

<body>
  <my-counter />
</body>

→ store demo

Add Omi in 30 Seconds

You can also quickly build omi projects using modern JS code:

import { tag, WeElement, render } from 'omi'

@tag('my-counter')
class MyCounter extends WeElement {
  count = 1

  static css = `
    span{
        color: red;
    }`

  sub = () => {
    this.count--
    this.update()
  }

  add = () => {
    this.count++
    this.update()
  }

  render() {
    return (
      <div>
        <button onClick={this.sub}>-</button>
        <span>{this.count}</span>
        <button onClick={this.add}>+</button>
      </div>
    )
  }
}

render(<my-counter />, 'body')

→ counter demo

Getting Started

Install

$ npm i omi-cli -g    # install cli
$ omi init my-app     # init project
$ cd my-app           
$ npm start           # develop
$ npm run build       # release

npx omi-cli init my-app is also supported(npm v5.2.0+).

Directory description:

├─ config
├─ public
├─ scripts
├─ src
│  ├─ assets
│  ├─ elements    //Store all custom elements
│  ├─ store       //Store all this store of pages
│  ├─ admin.js    //Entry js of compiler，will build to admin.html
│  └─ index.js    //Entry js of compiler，will build to index.html

Scripts

"scripts": {
    "start": "node scripts/start.js",
    "build": "PUBLIC_URL=. node scripts/build.js",
    "build-windows": "set PUBLIC_URL=.&& node scripts/build.js",
    "fix": "eslint src --fix"
}

You can set up the PUBLIC_URL, such as：

...
"build": "PUBLIC_URL=https://fe.wxpay.oa.com/dv node scripts/build.js",
"build-windows": "set PUBLIC_URL=https://fe.wxpay.oa.com/dv&& node scripts/build.js",
...

Switch omi, omio and reomi

Add or remove the alias config in package.json to switch omi and omio：

"alias": {
  "omi": "omio"
}

Project Template

Template Type	Command	Describe
Base Template(v3.3.0+)	omi init my-app	Basic omi or omio(IE8+) project template.
Base Template with snapshoot	omi init-snap my-app	Basic omi or omio(IE8+) project template with snapshoot prerendering.
TypeScript Template(omi-cli v3.3.0+)	omi init-ts my-app	Basic template with typescript.
Mobile Template	omi init-weui my-app	Mobile web app template with weui and omi-router.
omi-mp Template(omi-cli v3.0.13+)	omi init-mp my-app	Developing web with mini program template.

The base Template(omi init my-app) is based on a single-page create-react-app to be converted into a multi-page one, with configuration issues to see create-react-app user guide

Hello Element

Define a custom element by extending WeElement base class:

import { define, WeElement } from 'omi'

define('hello-element', class extends WeElement {
  onClick = evt => {
    // trigger CustomEvent
    this.fire('abc', { name: 'dntzhang', age: 12 })
    evt.stopPropagation()
  }

  //If you need to use <hello-element></hello-element> directly in html, you must declare propTypes
  static propTypes = {
    msg: String
  }

  static css = `
      div {
        color: red;
        cursor: pointer;
      }`

  render(props) {
    return (
      <div onClick={this.onClick}>
        Hello {props.msg}
        <div>Click Me!</div>
      </div>
    )
  }
})

Using hello-element:

import { define, render, WeElement } from 'omi'
import './hello-element'

define('my-app', class extends WeElement {
  data = { abc: 'abc' }

  // define CustomEvent Handler
  onAbc = evt => {
    // get evt data by evt.detail
    this.data.abc = ' by ' + evt.detail.name
    this.update()
  }

  static css = `
      div{
          color: green;
      }`
  }

  render(props, data) {
    return (
      <div>
        Hello {data.abc}
        <hello-element
          onAbc={this.onAbc}
          msg="WeElement"
        />
      </div>
    )
  }
})

render(<my-app name="Omi v4.0" />, 'body')

Tell Babel to transform JSX into Omi.h() call:

{
  "presets": ["env", "omi"]
}

The following two NPM packages need to be installed to support the above configuration:

"babel-preset-env": "^1.6.0",
"babel-preset-omi": "^0.1.1",

If you use babel7, you can also use the following packages and configuration:

npm install --save-dev @babel/preset-env
npm install --save-dev @babel/preset-react

{
  "presets": [
    "@babel/preset-env",
    [
      "@babel/preset-react",
      {
        "pragma": "Omi.h"
      }
    ]
  ]
}

If you don't want to write CSS in JS, you can use to-string-loader of webpack, For example, the following configuration:

{
  test: /[\\|\/]_[\S]*\.css$/,
  use: [
    'to-string-loader',
    'css-loader'
  ]
}

If your CSS file starts with "_", CSS will use to-string-loader, such as:

import { tag, WeElement render } from 'omi'

define('my-app', class extends WeElement {

  css = require('./_index.css')
  ...
  ...
  ...

You can also forget the tedious configuration and use omi-cli directly, no need to configure anything.

TodoApp

Here is a relatively complete example of TodoApp:

import { define, render, WeElement } from 'omi'

define('todo-list', class extends WeElement {
  static propTypes = {
    items: Array
  }

  render(props) {
    return (
      <ul>
        {props.items.map(item => (
          <li key={item.id}>{item.text}</li>
        ))}
      </ul>
    )
  }
})

define('todo-app', class extends WeElement {
  items = []
  text = ''

  render() {
    return (
      <div>
        <h3>TODO</h3>
        <todo-list items={this.items} />
        <form onSubmit={this.handleSubmit}>
          <input
            id="new-todo"
            onChange={this.handleChange}
            value={this.text}
          />
          <button>Add #{this.items.length + 1}</button>
        </form>
      </div>
    )
  }

  handleChange = e => {
    this.text = e.target.value
  }

  handleSubmit = e => {
    e.preventDefault()
    if (!this.text.trim().length) {
      return
    }
    this.items.push({
      text: this.text,
      id: Date.now()
    })
    this.text = ''
    this.update()
  }
})

render(<todo-app />, 'body')

TypeScript Auto Complete

import { h, WeElement, tag, classNames } from 'omi';
import * as styles from './_index.less';

interface ButtonProps {
  href?: string,
  disabled?: boolean,
  type?: 'default' | 'primary' | 'danger',
  htmltype?: 'submit' | 'button' | 'reset',
  onClick?: (e: any) => void
}

const TAG = 'o-button'

declare global {
  namespace JSX {
    interface IntrinsicElements {
      [TAG]: Omi.Props & ButtonProps
    }
  }
}

@tag(TAG)
export default class oButton extends WeElement<ButtonProps> {
...
...
...

Lifecycle

Lifecycle method	When it gets called
install	before the component gets mounted to the DOM
installed	after the component gets mounted to the DOM
uninstall	prior to removal from the DOM
beforeUpdate	before update
updated	after update
beforeRender	before render()
receiveProps	parent element re-render will trigger it, return false will prevent update action

Debugging

Easy to debug via Omi DevTools Extension [Install from Chrome WebStore], using Omi DevTools you can simply debug and manage your UI without any configuration. Just install and debug.

Since Omi uses Web Components and Shadow-DOM, it doesn't need to have another elements panel such as React has. It just adds a panel to the Elements' sidebar and it's powerful as much as React DevTools.

View registered elements

console.log(Omi.elements)

Browsers Support

Omio - Omi for old browsers(IE8+)

Omi works in the latest two versions of all major browsers: Safari 10+, IE 11+, and the evergreen Chrome, Firefox, and Edge.

→ Polyfills

<script src="https://unpkg.com/@webcomponents/webcomponentsjs@2.0.0/webcomponents-bundle.js"></script>

Contribution

Build a example:

npm start example_name

Build omi:

npm run build

Unit testing

npm run test

Contributors

Core Maintainers

• @Wscats
• @f
• @LeeHyungGeun
• @dntzhang
• @xcatliu

Please contact us for any questions.

Thanks

• preact
• htm
• create-react-app
• JSX
• JSONPatcherProxy

License

MIT © Tencent