【Vue】Vue Property Decorator详细使用手册

这个库完全依赖于​​vue-class-component​​，所以在使用这个库之前请阅读它的 README。

1、安装

npm

2、用法

有几个装饰器和 1 个函数（Mixin）：

• ​​@Prop​​
• ​​@PropSync​​
• ​​@Model​​
• ​​@ModelSync​​
• ​​@Watch​​
• ​​@Provide​​
• ​​@Inject​​
• ​​@ProvideReactive​​
• ​​@InjectReactive​​
• ​​@Emit​​
• ​​@Ref​​
• ​​@VModel​​
• ​​@Component​​​ (由​​vue-class-component​​提供)
• ​​Mixins​​​ (由​​vue-class-component​​提供的辅助函数命名)

3、参照

​​vuex-class​​

3.1 ​​@Prop(options: (PropOptions | Constructor[] | Constructor) = {})​​ 装饰器

import { Vue, Component, Prop } from 'vue-property-decorator'

@Component
export default class YourComponent extends Vue {
  @Prop(Number) readonly propA: number | undefined
  @Prop({ default: 'default value' }) readonly propB!: string
  @Prop([String, Boolean]) readonly propC: string | boolean | undefined
}

相当于

export default {
  props: {
    propA: {
      type: Number,
    },
    propB: {
      default: 'default value',
    },
    propC: {
      type: [String, Boolean],
    },
  },
}

3.1.1 如果从其类型定义中设置每个prop值的​​type​​​属性，可以使用 ​​reflect-metadata​​

1. 设置​​emitDecoratorMetadata​​​ 为​​true​​.
2. 导入​​reflect-metadata​​​ 前导入​​vue-property-decorator​​​ (​​reflect-metadata​​ 只需要导入一次)

import 'reflect-metadata'
import { Vue, Component, Prop } from 'vue-property-decorator'

@Component
export default class MyComponent extends Vue {
  @Prop() age!: number
}

3.1.2 每个prop的默认值需要定义为与上面的示例代码相同

不支持定义每个​​default​​​ 属性，例如​​@Prop() prop = 'default value'​​ .

3.2 ​​@PropSync(propName: string, options: (PropOptions | Constructor[] | Constructor) = {})​​ 装饰器

import { Vue, Component, PropSync } from 'vue-property-decorator'

@Component
export default class YourComponent extends Vue {
  @PropSync('name', { type: String }) syncedName!: string
}

相当于

export default {
  props: {
    name: {
      type: String,
    },
  },
  computed: {
    syncedName: {
      get() {
        return this.name
      },
      set(value) {
        this.$emit('update:name', value)
      },
    },
  },
}

​​@PropSync​​​ 使用方式类似 ​​@Prop​​ ，除将 propName 作为装饰器的参数之外，还在幕后创建了一个计算的 getter 和 setter。通过这种方式，您可以像与常规数据属性一样与属性交互，同时使其像.sync在父组件中附加修饰符一样简单。

3.3 ​​@Model(event?: string, options: (PropOptions | Constructor[] | Constructor) = {})​​ 装饰器

import { Vue, Component, Model } from 'vue-property-decorator'

@Component
export default class YourComponent extends Vue {
  @Model('change', { type: Boolean }) readonly checked!: boolean
}

相当于

export default {
  model: {
    prop: 'checked',
    event: 'change',
  },
  props: {
    checked: {
      type: Boolean,
    },
  },
}

​​@Model​​​ 也可以通过它的类型定义​​reflect-metadata​​​设置​​type​​属性。

3.4 ​​@ModelSync(propName: string, event?: string, options: (PropOptions | Constructor[] | Constructor) = {})​​ 装饰器

import { Vue, Component, ModelSync } from 'vue-property-decorator'

@Component
export default class YourComponent extends Vue {
  @ModelSync('checked', 'change', { type: Boolean })
  readonly checkedValue!: boolean
}

相当于

export default {
  model: {
    prop: 'checked',
    event: 'change',
  },
  props: {
    checked: {
      type: Boolean,
    },
  },
  computed: {
    checkedValue: {
      get() {
        return this.checked
      },
      set(value) {
        this.$emit('change', value)
      },
    },
  },
}

​​@ModelSyncproperty​​​ 也可以通过它的类型定义​​reflect-metadata​​​设置​​type​​属性。

3.5 ​​@Watch(path: string, options: WatchOptions = {})​​ 装饰器

import { Vue, Component, Watch } from 'vue-property-decorator'

@Component
export default class YourComponent extends Vue {
  @Watch('child')
  onChildChanged(val: string, oldVal: string) {}

  @Watch('person', { immediate: true, deep: true })
  onPersonChanged1(val: Person, oldVal: Person) {}

  @Watch('person')
  onPersonChanged2(val: Person, oldVal: Person) {}

  @Watch('person')
  @Watch('child')
  onPersonAndChildChanged() {}
}

相当于

export default {
  watch: {
    child: [
      {
        handler: 'onChildChanged',
        immediate: false,
        deep: false,
      },
      {
        handler: 'onPersonAndChildChanged',
        immediate: false,
        deep: false,
      },
    ],
    person: [
      {
        handler: 'onPersonChanged1',
        immediate: true,
        deep: true,
      },
      {
        handler: 'onPersonChanged2',
        immediate: false,
        deep: false,
      },
      {
        handler: 'onPersonAndChildChanged',
        immediate: false,
        deep: false,
      },
    ],
  },
  methods: {
    onChildChanged(val,) {},
    onPersonChanged1(val,) {},
    onPersonChanged2(val,) {},
    onPersonAndChildChanged() {},
  },
}

3.6 ​​@Provide(key?: string | symbol)​​​ / ​​@Inject(options?: { from?: InjectKey, default?: any } | InjectKey)​​ 装饰器

import { Component, Inject, Provide, Vue } from 'vue-property-decorator'

const symbol = Symbol('baz')

@Component
export class MyComponent extends Vue {
  @Inject() readonly foo!: string
  @Inject('bar') readonly bar!: string
  @Inject({ from: 'optional', default: 'default' }) readonly optional!: string
  @Inject(symbol) readonly baz!: string

  @Provide() foo = 'foo'
  @Provide('bar') baz = 'bar'
}

相当于

const symbol = Symbol('baz')

export const MyComponent = Vue.extend({
  inject: {
    foo: 'foo',
    bar: 'bar',
    optional: { from: 'optional', default: 'default' },
    baz: symbol,
  },
  data() {
    return {
      foo: 'foo',
      baz: 'bar',
    }
  },
  provide() {
    return {
      foo: this.foo,
      bar: this.baz,
    }
  },
})

3.7 ​​@ProvideReactive(key?: string | symbol)​​​ / ​​@InjectReactive(options?: { from?: InjectKey, default?: any } | InjectKey)​​ 装饰器

这些装饰器是​​@Provide​​​和的反应式版本​​@Inject​​。如果父组件修改了提供的值，则子组件可以捕获此修改。

const key = Symbol()
@Component
class ParentComponent extends Vue {
  @ProvideReactive() one = 'value'
  @ProvideReactive(key) two = 'value'
}

@Component
class ChildComponent extends Vue {
  @InjectReactive() one!: string
  @InjectReactive(key) two!: string
}

3.8 ​​@Emit(event?: string)​​ 装饰器

由​​@Emit​​​ ​​$emit​​后跟它们的原始参数作为返回值修饰的函数。如果返回值是一个 Promise，它会在发出之前被解析。

如果未通过​​event​​参数提供事件名称，则使用函数名称。在这种情况下，camelCase 名称将转换为 kebab-case。

import { Vue, Component, Emit } from 'vue-property-decorator'

@Component
export default class YourComponent extends Vue {
  count = 0

  @Emit()
  addToCount(n: number) {
    this.count += n
  }

  @Emit('reset')
  resetCount() {
    this.count = 0
  }

  @Emit()
  returnValue() {
    return 10
  }

  @Emit()
  onInputChange(e) {
    return e.target.value
  }

  @Emit()
  promise() {
    return new Promise((resolve) => {
      setTimeout(() => {
        resolve(20)
      }, 0)
    })
  }
}

相当于

export default {
  data() {
    return {
      count: 0,
    }
  },
  methods: {
    addToCount(n) {
      this.count += n
      this.$emit('add-to-count', n)
    },
    resetCount() {
      this.count = 0
      this.$emit('reset')
    },
    returnValue() {
      this.$emit('return-value', 10)
    },
    onInputChange(e) {
      this.$emit('on-input-change', e.target.value, e)
    },
    promise() {
      const promise = new Promise((resolve) => {
        setTimeout(() => {
          resolve(20)
        }, 0)
      })

      promise.then((value) => {
        this.$emit('promise', value)
      })
    },
  },
}

3.9 ​​@Ref(refKey?: string)​​ 装饰器

import { Vue, Component, Ref } from 'vue-property-decorator'

import AnotherComponent from '@/path/to/another-component.vue'

@Component
export default class YourComponent extends Vue {
  @Ref() readonly anotherComponent!: AnotherComponent
  @Ref('aButton') readonly button!: HTMLButtonElement
}

相当于

export default {
  computed() {
    anotherComponent: {
      cache: false,
      get() {
        return this.$refs.anotherComponent as AnotherComponent
      }
    },
    button: {
      cache: false,
      get() {
        return this.$refs.aButton as HTMLButtonElement
      }
    }
  }
}

3.10 ​​@VModel(propsArgs?: PropOptions)​​ 装饰器

import { Vue, Component, VModel } from 'vue-property-decorator'

@Component
export default class YourComponent extends Vue {
  @VModel({ type: String }) name!: string
}

相当于

export default {
  props: {
    value: {
      type: String,
    },
  },
  computed: {
    name: {
      get() {
        return this.value
      },
      set(value) {
        this.$emit('input', value)
      },
    },
  },
}