React簡單解釋如何封裝元件的demo
阿新 • • 發佈:2018-12-30
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Reactjs in 40 </title>
<style media="screen">
.like-btn { font-size: 50px; }
</style>
</head>
<body>
<div class='wrapper'></div>
</body>
<script type ="text/javascript">
/* Component */
class Component {
constructor (props = {}) {
this.props = props
}
setState (state) {
const oldEl = this.el
this.state = state
this.el = this.renderDOM()
if (this.onStateChange) this.onStateChange(oldEl, this .el)
}
renderDOM () {
this.el = createDOMFromString(this.render())
if (this.onClick) {
this.el.addEventListener('click', this.onClick.bind(this), false)
}
return this.el
}
}
const createDOMFromString = (domString) => {
const div = document.createElement('div' )
div.innerHTML = domString
return div
}
const mount = (component, wrapper) => {
wrapper.appendChild(component.renderDOM())
component.onStateChange = (oldEl, newEl) => {
wrapper.insertBefore(newEl, oldEl)
wrapper.removeChild(oldEl)
}
}
/* ========================================= */
class LikeButton extends Component {
constructor (props) {
super(props)
this.state = { isLiked: false }
}
onClick () {
this.setState({
isLiked: !this.state.isLiked
})
}
render () {
return `
<button class='like-btn' style="background-color: ${this.props.bgColor}">
<span class='like-text'>
${this.state.isLiked ? '取消' : '點贊'}
</span>
<span>��</span>
</button>
`
}
}
class RedBlueButton extends Component {
constructor (props) {
super(props)
this.state = {
color: 'red'
}
}
onClick () {
this.setState({
color: 'blue'
})
}
render () {
return `
<div style='color: ${this.state.color};'>${this.state.color}</div>
`
}
}
const wrapper = document.querySelector('.wrapper')
mount(new LikeButton({ bgColor: 'red' }), wrapper)
mount(new LikeButton(), wrapper)
mount(new RedBlueButton(), wrapper)
</script>
</html>