Suspense

Suspense 是 Vue3 推出的一个内置的特殊组件

如果使用 Suspense，要返回一个 promise

Suspense

src/components/AsyncShow.vue:

<template>
  <h1>{{ result }}</h1>
</template>

<script lang="ts">
import { defineComponent } from 'vue';
export default defineComponent({
  setup() {
    return new Promise((resolve) => {
      setTimeout(() => {
        return resolve({
          result: 42
        })
      }, 3000)
    })
  }
});
</script>


<style scoped>
</style>

src/App.vue:

<template>
  <div id="app">
    <img alt="Vue logo" src="./assets/logo.png">
    <h1>{{ count }}</h1>
    <h1>{{ double }}</h1>
    <h1>{{ greetings }}</h1>
    <Suspense>
      <template #default>
        <async-show></async-show>
      </template>
      <template #fallback>
        <h1>Loading !...</h1>
      </template>
    </Suspense>
    <button @click="openModal">Open Modal</button><br>
    <h1 v-if="loading">Loading!...</h1>
    <img v-if="loaded" :src="result[0].url">
    <h1>X: {{ x }}, Y: {{ y }}</h1>
    <modal :isOpen="modalIsOpen" @close-modal="onModalClose"> My Modal !!!!</modal>
    <button @click="increase">👍+1</button><br>
    <button @click="updateGreeting">Update Title</button>
  </div>
</template>

<script lang="ts">
import { ref, computed, reactive, toRefs, watch } from 'vue';
import useMousePosition from './hooks/useMousePosition'
import useURLLoader from './hooks/useURLLoader'
import Modal from './components/Modal.vue'
import AsyncShow from './components/AsyncShow.vue'


interface DataProps {
  count: number;
  double: number;
  increase: () => void;
}
interface DogResult {
  message: string;
  status: string;
}
interface CatResult {
  id: string;
  url: string;
  width: number;
  height: number;
}

export default ({
  name: 'App',
  components: {
    Modal,
    AsyncShow
  },
  setup() {
    const data: DataProps = reactive({
      count: 0,
      increase: () => { data.count++ },
      double: computed(() => data.count * 2),
    })
    const { x, y } = useMousePosition()
    const { result, loading, loaded } = useURLLoader<CatResult[]>('https://api.thecatapi.com/v1/images/search?limit=1')
    watch(result, () => {
      if (result.value) {
        console.log(result.value[0].url)
      }
    })
    const greetings = ref('')
    const updateGreeting = () => {
      console.log('hhhh')
      greetings.value += 'Hello! '
    }
    watch([greetings, () => data.count], (newValue, oldValue) => {
      console.log('old', oldValue)
      console.log('new', newValue)
      document.title = 'updated' + greetings.value + data.count
    })
    const refData = toRefs(data)
    const modalIsOpen = ref(false)
    const openModal = () => {
      modalIsOpen.value = true
    }
    const onModalClose = () => {
      modalIsOpen.value = false
    }
    return {
      ...refData,
      greetings,
      updateGreeting,
      x,
      y,
      result,
      loading,
      loaded,
      modalIsOpen,
      onModalClose,
      openModal
    }
  }
});
</script>

<style>
#app {
  font-family: Avenir, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
  margin-top: 60px;
}
</style>

真实例子

src/components/DogShow.vue:

<template>
  <img :src="result && result.message">
</template>

<script lang="ts">
import { defineComponent } from 'vue';
import axios from 'axios'
export default defineComponent({
  async setup() {
    const rawData = await axios.get('https://dog.ceo/api/breeds/image/random')
    return {
      result: rawData.data
    }
  }
});
</script>


<style scoped>
</style>

`src/App.vue:

<template>
  <div id="app">
    <img alt="Vue logo" src="./assets/logo.png">
    <h1>{{ count }}</h1>
    <h1>{{ double }}</h1>
    <h1>{{ greetings }}</h1>
    <Suspense>
      <template #default>
        <dog-show></dog-show>
      </template>
      <template #fallback>
        <h1>Loading !...</h1>
      </template>
    </Suspense>
    <h1 v-if="loading">Loading!...</h1>
    <img v-if="loaded" :src="result[0].url">
    <h1>X: {{ x }}, Y: {{ y }}</h1>
    <button @click="increase">👍+1</button><br>
    <button @click="updateGreeting">Update Title</button>
  </div>
</template>

<script lang="ts">
import { ref, computed, reactive, toRefs, watch } from 'vue';
import useMousePosition from './hooks/useMousePosition'
import useURLLoader from './hooks/useURLLoader'
import DogShow from './components/DogShow.vue'


interface DataProps {
  count: number;
  double: number;
  increase: () => void;
}
interface DogResult {
  message: string;
  status: string;
}
interface CatResult {
  id: string;
  url: string;
  width: number;
  height: number;
}

export default ({
  name: 'App',
  components: {
    DogShow
  },
  setup() {
    const data: DataProps = reactive({
      count: 0,
      increase: () => { data.count++ },
      double: computed(() => data.count * 2),
    })
    const { x, y } = useMousePosition()
    const { result, loading, loaded } = useURLLoader<CatResult[]>('https://api.thecatapi.com/v1/images/search?limit=1')
    watch(result, () => {
      if (result.value) {
        console.log(result.value[0].url)
      }
    })
    const greetings = ref('')
    const updateGreeting = () => {
      console.log('hhhh')
      greetings.value += 'Hello! '
    }
    watch([greetings, () => data.count], (newValue, oldValue) => {
      console.log('old', oldValue)
      console.log('new', newValue)
      document.title = 'updated' + greetings.value + data.count
    })
    const refData = toRefs(data)
    const modalIsOpen = ref(false)
    const openModal = () => {
      modalIsOpen.value = true
    }
    const onModalClose = () => {
      modalIsOpen.value = false
    }
    return {
      ...refData,
      greetings,
      updateGreeting,
      x,
      y,
      result,
      loading,
      loaded,
      modalIsOpen,
      onModalClose,
      openModal
    }
  }
});
</script>

<style>
#app {
  font-family: Avenir, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
  margin-top: 60px;
}
</style>

抓取错误

src/App.vue:

<template>
  <div id="app">
    <img alt="Vue logo" src="./assets/logo.png">
    <h1>{{ count }}</h1>
    <h1>{{ double }}</h1>
    <h1>{{ greetings }}</h1>
    <p>{{ error }}</p>
    <Suspense>
      <template #default>
        <dog-show></dog-show>
      </template>
      <template #fallback>
        <h1>Loading !...</h1>
      </template>
    </Suspense>
    <h1 v-if="loading">Loading!...</h1>
    <img v-if="loaded" :src="result[0].url">
    <h1>X: {{ x }}, Y: {{ y }}</h1>
    <button @click="increase">👍+1</button><br>
    <button @click="updateGreeting">Update Title</button>
  </div>
</template>

<script lang="ts">
import { ref, computed, reactive, toRefs, watch, onErrorCaptured } from 'vue';
import useMousePosition from './hooks/useMousePosition'
import useURLLoader from './hooks/useURLLoader'
import DogShow from './components/DogShow.vue'


interface DataProps {
  count: number;
  double: number;
  increase: () => void;
}
interface DogResult {
  message: string;
  status: string;
}
interface CatResult {
  id: string;
  url: string;
  width: number;
  height: number;
}

export default ({
  name: 'App',
  components: {
    DogShow
  },
  setup() {
    const error = ref(null)
    onErrorCaptured((e: any) => {
      error.value = e
      return true
    })
    const data: DataProps = reactive({
      count: 0,
      increase: () => { data.count++ },
      double: computed(() => data.count * 2),
    })
    const { x, y } = useMousePosition()
    const { result, loading, loaded } = useURLLoader<CatResult[]>('https://api.thecatapi.com/v1/images/search?limit=1')
    watch(result, () => {
      if (result.value) {
        console.log(result.value[0].url)
      }
    })
    const greetings = ref('')
    const updateGreeting = () => {
      console.log('hhhh')
      greetings.value += 'Hello! '
    }
    watch([greetings, () => data.count], (newValue, oldValue) => {
      console.log('old', oldValue)
      console.log('new', newValue)
      document.title = 'updated' + greetings.value + data.count
    })
    const refData = toRefs(data)
    const modalIsOpen = ref(false)
    const openModal = () => {
      modalIsOpen.value = true
    }
    const onModalClose = () => {
      modalIsOpen.value = false
    }
    return {
      ...refData,
      greetings,
      updateGreeting,
      x,
      y,
      result,
      loading,
      loaded,
      modalIsOpen,
      onModalClose,
      openModal,
      error
    }
  }
});
</script>

<style>
#app {
  font-family: Avenir, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
  margin-top: 60px;
}
</style>