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Omi

Omi === Preact + Scoped CSS + Store System + Native Support in 3kb javascript.

Omi has prosperous ecology and strong features through the second-hand preact developments:

• Super tiny size and Super fast
• Extensive React/Preact/Omi compatibility
• Scoped CSS, made css selector simple, lazy evaluation and package with it's component
• Each component has a update method, you can continue to use setState
• Store system, data and logic of components management for omi without other frameworks dependencies
• Server side render, Native Suppport, ES6+, JSX, VDOM, React DevTools, HMR ...
• Create website with no build configuration if you use omi-cli, the same as multi-page support of create-react-app

---

• Getting Started
  • Hello Omi
  • Scoped CSS
  • Store
  • Lifecycle
• CLI
• Install
• Official Plugins
• Links
• License

Getting Started

Hello Omi

import { render, Component } from 'omi';

class Hello extends Component {
    render() {
        return <div> {this.props.name}</div>
    }
}

class App extends Component {
    install() {
        this.name = 'Omi'
    }

    handleClick = (e) => {
        this.name = 'Hello Omi !' 
        this.update()
    }

    style() {
        return `h3{
                    cursor:pointer;
                    color: ${Math.random() > 0.5 ? 'red' :'green'};
                }`
        }

    staticStyle() {
        return `div{
                    font-size:20px;
                }`
        }
	
    render() {
        return (
		<div>
			<Hello name={this.name}></Hello>
			<h3 onclick={this.handleClick}>Scoped css and event test! click me!</h3>
		</div>
		)
    }
}

render(<App />, 'body')

Different to preact, you need not to import { h } from 'omi'.

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

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

You need install env and omi preset for the config:

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

Scoped CSS

What'S the different between style and staticStyle method ? For example：

render() {
        return (
		<div>
			<Hello name={this.name}></Hello>
			<Hello name={this.name}></Hello>
			<Hello name={this.name}></Hello>
		</div>
		)
    }

The style method will render three times to html head element, the staticStyle will render one times only ! When you update the component style method will rerender, but the staticStyle will not rerender.

If you want to use the scoped css but you did not want write it in your javascript, you may need to-string-loader, see the omi-cli config：

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

If your css file name is begin with _, the css content will use to-string-loader. For example：

import Omi from 'omi'
//typeof style is string
import style from './_index.css' 

class App extends Omi.Component {

  staticStyle() {
    return style
  }

  style() {
    return `
      code{
        color: ${Math.random() > 0.5 ? 'red' : 'blue'}
      }
      .app-logo{
        cursor: pointer; 
      }
    `
  }

  render() {
    return (
      <div class="app">
        <header class="app-header">
          <h1 class="app-title">Welcome to Omi</h1>
        </header>
      </div>
    )
  }
}

You can use the feature in the project created by omi-cli with no configuration.

Store

import { render, Component } from 'omi';

class Hello extends Component {
  render() {
    return <div>{this.props.name}</div>
  }
}

class App extends Component {

  handleClick = () => {
    this.$store.rename('Hello Omi !')
  }

  render() {
    return (
      <div>
        <Hello name={this.$store.name}></Hello>
        <button onclick={this.handleClick}>Click me to call this.$store.rename('Hello Omi !') </button>
      </div>
    )
  }
}

class AppStore {
  constructor(data, callbacks) {
    this.name = data.name || ''
    this.onRename = callbacks.onRename || function () { }
  }

  rename(name) {
    this.name = name
    this.onRename()
  }
}

const app = new App()
const store = new AppStore({ name: 'Omi' }, {
  onRename: () => {
    app.update()
  }
})

render(app, document.body, { store })

You can use this.$store in all components to access the data or data logic.

Lifecycle

Lifecycle method	When it gets called
componentWillMount / install	before the component gets mounted to the DOM
componentDidMount / installed	after the component gets mounted to the DOM
componentWillUnmount / uninstall	prior to removal from the DOM
componentWillReceiveProps	before new props get accepted
shouldComponentUpdate	before render(). Return false to skip render
componentWillUpdate / beforeUpdate	before render()
componentDidUpdate / afterUpdate	after render()

CLI

$ npm i omi-cli -g               # install cli
$ omi init your_project_name     # init project, you can also exec 'omi init' in an empty folder
$ cd your_project_name           # please ignore this command if you executed 'omi init' in an empty folder
$ npm start                      # develop
$ npm run build                  # release

Server Side Render:

$ omi init-ssr your_project_name     # init ssr project, you can also exec 'omi init-ssr' in an empty folder
$ cd your_project_name               # please ignore this command if you executed 'omi init' in an empty folder
$ npm run dev                        # develop
$ npm run build                      # release
$ npm start                          # release 

Install

npm i omi

or get it from CDN:

• https://unpkg.com/omi@3.0.6/dist/omi.min.js
• https://unpkg.com/omi@3.0.6/dist/omi.js

Official Plugins

• omi-tap: Support tap event in your Omi project.
• omi-router: Router for Omi.
• omi-finger: Omi /AlloyFinger integration.
• omi-transform: Omi /transformjs integration.
• omi-touch: Omi /AlloyTouch integration.

Links

• preact github
• preactjs.com
• omijs.org
• differences to react
• native support

License

MIT © dntzhang