Vue3通用API功能示例剖析

import Vue from 'vue';
export default {
    setup(props, context) {
        console.log(Vue.version);
        return {};
    }
};

function nextTick(callback?: () => void): Promise<void>

<template>
    <div class="test_demo">
        <h2 class="text">{{ text }}</h2>
        <button @click="onBtnClick">更新</button>
    </div>
</template>
<script lang="ts" setup>
import { ref, nextTick } from 'vue';
const text = ref('test_0');
const onBtnClick = () => {
    text.value = 'test_1';
    nextTick(() => {
        const text = (
            document.querySelector<htmlElement>('.text') as HTMLElement
        ).innerText;
        console.log(text);
    });
    text.value = 'test_2';
};
</script>

<script setup lang="ts">
// 启用了 TypeScript
import { ref } from 'vue'
const props = defineProps({ msg: String })
const count = ref(1)
</script>
<template>
  <!-- 启用了类型检查和自动补全 -->
  {{ count.toFixed(2) }}
</template>

import { defineComponent } from 'vue'
export default defineComponent({
  // 启用了类型推导
  props: {
    message: String
  },
  setup(props) {
    props.message // 类型：string | undefined
  }
})

export default  defineComponent()

import { defineAsyncComponent } from 'vue';
const AsyncComp = defineAsyncComponent(() => {
    return new Promise((resolve, reject) => {
        // ...从服务器获取组件
        resolve();
    });
});

import { defineAsyncComponent } from 'vue';
const AsyncComp = defineAsyncComponent(
    () => import('./components/MyComponent.vue')
);

 const AsyncComp = defineAsyncComponent({
        // 加载函数
        loader: () => import('./Foo.vue'),
        // 加载异步组件时使用的组件
        loadinGComponent: LoadingComponent,
        // 展示加载组件前的延迟时间，默认为 200ms
        delay: 200,
        // 加载失败后展示的组件
        errorComponent: ErrorComponent,
        // 如果提供了一个 timeout 时间限制，并超时了
        // 也会显示这里配置的报错组件，默认值是：Infinity
        timeout: 3000
    });

import { defineCustomElement } from 'vue';
const MyVueElement = defineCustomElement({
    
});
// 注册自定义元素
customElements.define('my-vue-element', MyVueElement);