指令 Directive 
用法 
Omi 的 directive 能力允许你在组件中使用自定义指令,从而在运行时对 DOM 进行操作和处理。
下面是一个 Omi directive 的简单示例:
tsx
import { tag, render, Component, registerDirective, h } from 'omi'
registerDirective('test', (el, exp) => {
  el.style.cssText = exp
})
@tag('my-app')
class MyApp extends Component {
  static css = `div {color: red;}`
  render() {
    return (
      <div o-test="color:blue;">Hello Omi!</div>
    )
  }
}
render(<my-app />, 'body')import { tag, render, Component, registerDirective, h } from 'omi'
registerDirective('test', (el, exp) => {
  el.style.cssText = exp
})
@tag('my-app')
class MyApp extends Component {
  static css = `div {color: red;}`
  render() {
    return (
      <div o-test="color:blue;">Hello Omi!</div>
    )
  }
}
render(<my-app />, 'body')