1. vue3 的新特性

• 组合式 API: ref & reactive & onMounted & watch & computed & toRefs

// src/components/UserRepositories.vue `setup` function
import { fetchUserRepositories } from '@/api/repositories'
import { ref, onMounted, watch, toRefs, computed } from 'vue'

// 在我们的组件中
setup (props) {
  // 使用 `toRefs` 创建对 props 中的 `user` property 的响应式引用
  const { user } = toRefs(props)

  const repositories = ref([])
  const getUserRepositories = async () => {
    // 更新 `props.user ` 到 `user.value` 访问引用值
    repositories.value = await fetchUserRepositories(user.value)
  }

  onMounted(getUserRepositories)

  // 在 user prop 的响应式引用上设置一个侦听器
  watch(user, getUserRepositories)

  const searchQuery = ref('')
  const repositoriesMatchingSearchQuery = computed(() => {
    return repositories.value.filter(
      repository => repository.name.includes(searchQuery.value)
    )
  })

  return {
    repositories,
    getUserRepositories,
    searchQuery,
    repositoriesMatchingSearchQuery
  }
}

• script setup

  • defineProps & defineEmits
  • directive 指令
  • defineExpose
  • useSlots & useAttrs

• v-model: 现在可以在同一个自定义组件上使用多个 v-model 绑定；

• 创建自定义渲染器: import { createRenderer } from '@vue/runtime-core'

• <style> v-bind

<template>
  <div class="text">hello</div>
</template>

<script>
export default {
  data() {
    return {
      color: 'red'
    }
  }
}
</script>

<style>
.text {
  color: v-bind(color);
}
</style>

• SFC <style scoped>

<style scoped>
/* deep selectors */
::v-deep(.foo) {}
/* shorthand */
:deep(.foo) {}

/* targeting slot content */
::v-slotted(.foo) {}
/* shorthand */
:slotted(.foo) {}

/* one-off global rule */
::v-global(.foo) {}
/* shorthand */
:global(.foo) {}
</style>