Composition API 纯函数式
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<div id="app"></div>
<script src="./vue.global.js"></script>
<script>
// Composition API
const {reactive, onMounted, effect, createApp, onRenderTriggered, computed, watch, onBeforeMount, createComponent} = Vue;
function hooks() {
let data = reactive({name: 'SpongeBob'});
onBeforeMount(() => {
console.log('hooks-------dom加载')
});
onMounted(() => {
console.log('hooks-------dom加载完了');
setTimeout(() => {
data.name = 'hooks'
}, 2000)
});
return {
data
}
}
const Count = createComponent({
template: `<div>
<div style="background: #ccc;" @click="back()">
{{props.age}}
</div>
</div>`,
// props: {
// age: {
// type: Number
// },
// onBack: {
// type: Function
// }
// },
setup (props, context) {
console.log('接收到父组件传值为', props);
console.log(context);
const back = () => {
// 调用父组件方法 并传递参数
props.onBack('OK')
};
onMounted(() => {
console.log('组件-------dom加载完了');
});
return {
back,
props: props
}
}
});
const App = {
template: `<div style=" 100px;">
<div>name:{{data.name}}</div>
<div style="background: red;" @click="other()">age:{{count.age}}</div>
<div>{{plusOne}}</div>
<Count :age="count.age" @back="onBack"></Count>
</div>`,
components: { Count },
// beforeCreate && created
setup () {
// hooks
const { data } = hooks();
// data
const count = reactive({age: 18});
// computed
const plusOne = computed(() => '当前值:' + count.age);
// method
const other = () => {
count.age++;
};
const onBack = (val) => {
console.log('收到子组件------', val);
count.age--;
};
// watch
watch(() => count.age, (v) => console.log('监听到' + v));
// beforeMounted
onBeforeMount(() => {
console.log('beforeMounted-------dom加载')
setTimeout(() => {
data.name = 'SpongeBob'
}, 5000)
});
// mounted
onMounted(() => {
console.log('mounted-------dom加载完了')
});
// beforeUpdate -> onBeforeUpdate
// updated -> onUpdated
// beforeDestroy -> onBeforeUnmount
// destroyed -> onUnmounted
// errorCaptured -> onErrorCaptured
// 响应式 副作用
effect(() => {
console.log('effect--------' + count.age)
});
// 返回触发视图更新的事件对象
onRenderTriggered((event) => {
// debugger;
console.log('视图更新---------', event)
});
return {
data, count, // data
plusOne, // computed
other, onBack // method
}
}
};
// 挂载
let app = document.getElementById('app');
let container = createApp().mount(App, app);
console.log(container)
</script>
</body>
</html>
Tree-shaking 按需引入 工具函数 // 可以根据所需要的的API引入
新增响应式数据监听API // reactive effect 主要用来实现跨组件之间状态共享
reactive 监听数据的5个状态
effect 初始化触发一次 数据改变触发一次
触发组件更新 用于排查 // onRenderTriggered 返回触发视图更新的事件对象
props传值 以及子组件调用父组件方法
// 传递
// 接收
props为proxy对象 内置父组件传递的值以及方法 方法可以直接调用 可传递参数
context为上下文对象
参考React Hooks (Experimental Hooks) 逻辑复用机制 及Vue Hooks 用于取代mixins