一文秒懂vue-property-decorator

2024-04-02 19:04:59 627人浏览八月长安

摘要

目录我们来看下页面上代码展示:1.@Component(options:ComponentOptions = {})2.@Prop(options: (PropOptions | C

我们来看下页面上代码展示:
1.@Component(options:ComponentOptions = {})
2.@Prop(options: (PropOptions | Constructor[] | Constructor) = {})
3，@PropSync(propName: string, options: (PropOptions | Constructor[] | Constructor) = {})
4.@Model(event?: string, options: (PropOptions | Constructor[] | Constructor) = {})
5，@Watch(path: string, options: WatchOptions = {})
6，@Emit(event?: string)
7，@Ref(refKey?: string)
8.Provide/Inject ProvideReactive/InjectReactive

参考:https://GitHub.com/kaorun343/Vue-property-decorator
怎么使vue支持ts写法呢,我们需要用到vue-property-decorator,这个组件完全依赖于vue-class-component.

首先安装: npm i -D vue-property-decorator

我们来看下页面上代码展示:

<template>
  <div>
    foo:{{foo}}
    defaultArg:{{defaultArg}} | {{countplus}}
    <button @click="delToCount($event)">点击del emit</button>
    <HellowWordComponent></HellowWordComponent>
    <button ref="aButton">ref</button>
  </div>
</template>
 
<script lang="ts">
import { Component, Vue, Prop, Emit, Ref } from 'vue-property-decorator';
import HellowWordComponent from '@/components/HellowWordComponent.vue';
 
@Component({
  components: {
    HellowWordComponent,
  },
  beforeRouteLeave(to: any, from: any, next: any) {
    console.log('beforeRouteLeave');
    next();
  },
  beforeRouteEnter(to: any, from: any, next: any) {
    console.log('beforeRouteLeave');
    next();
  },
})
 
export default class DemoComponent extends Vue {
  private foo = 'App Foo!';
 
  private count: number = this.$store.state.count;
 
  @Prop(Boolean) private defaultArg: string | undefined;
 
  @Emit('delemit') private delEmitClick(event: MouseEvent) {}
 
  @Ref('aButton') readonly ref!: htmlButtonElement;
 
  // computed;
  get countplus () {
    return this.count;
  }
 
  created() {}
 
  mounted() {}
 
  beforeDestroy() {}
 
  public delToCount(event: MouseEvent) {
    this.delEmitClick(event);
    this.count += 1; // countplus 会累加
  }
 
}
 
</script>
 
<style lang="less">
...
</style>

vue-proporty-decorator它具备以下几个装饰器和功能:

@Component
@Prop
@PropSync
@Model
@Watch
@Provide
@Inject
@ProvideReactive
@InjectReactive
@Emit
@Ref

1.@Component(options:ComponentOptions = {})

@Component 装饰器可以接收一个对象作为参数，可以在对象中声明 components ，filters，directives等未提供装饰器的选项，也可以声明computed，watch等

reGISterHooks:
除了上面介绍的将beforeRouteLeave放在Component中之外,还可以全局注册,就是registerHooks

<script lang="ts">
import { Component, Vue } from 'vue-property-decorator';
 
Component.registerHooks([
  'beforeRouteLeave',
  'beforeRouteEnter',
]);
 
@Component
export default class App extends Vue {
  beforeRouteLeave(to: any, from: any, next: any) {
    console.log('beforeRouteLeave');
    next();
  }
 
  beforeRouteEnter(to: any, from: any, next: any) {
    console.log('beforeRouteLeave');
    next();
  }
}
</script>

2.@Prop(options: (PropOptions | Constructor[] | Constructor) = {})

@Prop装饰器接收一个参数，这个参数可以有三种写法：

Constructor，例如String，Number，Boolean等，指定 prop 的类型；
Constructor[]，指定 prop 的可选类型；
PropOptions，可以使用以下选项：type，default，required，validator。

注意:属性的ts类型后面需要加上undefined类型；或者在属性名后面加上!，表示非null 和 非undefined
的断言，否则编译器会给出错误提示；

// 父组件:
<template>
  <div class="Props">
    <PropComponent :name="name" :age="age" :sex="sex"></PropComponent>
  </div>
</template>
 
<script lang="ts">
import {Component, Vue,} from 'vue-property-decorator';
import PropComponent from '@/components/PropComponent.vue';
 
@Component({
  components: {PropComponent,},
})
export default class PropsPage extends Vue {
  private name = '张三';
  private age = 1;
  private sex = 'nan';
}
</script>
 
// 子组件:
<template>
  <div class="hello">
    name: {{name}} | age: {{age}} | sex: {{sex}}
  </div>
</template>
 
<script lang="ts">
import {Component, Vue, Prop} from 'vue-property-decorator';
 
@Component
export default class PropComponent extends Vue {
   @Prop(String) readonly name!: string | undefined;
   @Prop({ default: 30, type: Number }) private age!: number;
   @Prop([String, Boolean]) private sex!: string | boolean;
}
</script>

3，@PropSync(propName: string, options: (PropOptions | Constructor[] | Constructor) = {})

@PropSync装饰器与@prop用法类似，二者的区别在于：

@PropSync 装饰器接收两个参数：

propName: string 表示父组件传递过来的属性名；

options: Constructor | Constructor[] | PropOptions 与@Prop的第一个参数一致；@PropSync 会生成一个新的计算属性。

注意,使用PropSync的时候是要在父组件配合.sync使用的

// 父组件
<template>
  <div class="PropSync">
    <h1>父组件</h1>
    like:{{like}}
    <hr/>
    <PropSyncComponent :like.sync="like"></PropSyncComponent>
  </div>
</template>
 
<script lang='ts'>
import { Vue, Component } from 'vue-property-decorator';
import PropSyncComponent from '@/components/PropSyncComponent.vue';
 
@Component({components: { PropSyncComponent },})
export default class PropSyncPage extends Vue {
  private like = '父组件的like';
}
</script>
 
// 子组件
<template>
  <div class="hello">
    <h1>子组件:</h1>
    <h2>syncedlike:{{ syncedlike }}</h2>
    <button @click="editLike()">修改like</button>
  </div>
</template>
 
<script lang="ts">
import { Component, Prop, Vue, PropSync,} from 'vue-property-decorator';
 
@Component
export default class PropSyncComponent extends Vue {
  @PropSync('like', { type: String }) syncedlike!: string; // 用来实现组件的双向绑定,子组件可以更改父组件穿过来的值
 
  editLike(): void {
    this.syncedlike = '子组件修改过后的syncedlike!'; // 双向绑定,更改syncedlike会更改父组件的like
  }
}
</script>

4.@Model(event?: string, options: (PropOptions | Constructor[] | Constructor) = {})

@Model装饰器允许我们在一个组件上自定义v-model，接收两个参数：

event: string 事件名。
options: Constructor | Constructor[] | PropOptions 与@Prop的第一个参数一致。

注意,有看不懂的,可以去看下vue官网文档, Https://cn.vuejs.org/v2/api/#model

// 父组件
<template>
  <div class="Model">
    <ModelComponent v-model="fooTs" value="some value"></ModelComponent>
    <div>父组件 app : {{fooTs}}</div>
  </div>
</template>
<script lang="ts">
import { Component, Vue } from 'vue-property-decorator';
import ModelComponent from '@/components/ModelComponent.vue';
 
@Component({ components: {ModelComponent} })
export default class ModelPage extends Vue {
  private fooTs = 'App Foo!';
}
</script>
 
// 子组件
<template>
  <div class="hello">
    子组件:<input type="text" :value="checked" @input="inputHandle($event)"/>
  </div>
</template>
 
<script lang="ts">
import {Component, Vue, Model,} from 'vue-property-decorator';
 
@Component
export default class ModelComponent extends Vue {
   @Model('change', { type: String }) readonly checked!: string
 
   public inputHandle(that: any): void {
     this.$emit('change', that.target.value); // 后面会讲到@Emit,此处就先使用this.$emit代替
   }
}
</script>

5，@Watch(path: string, options: WatchOptions = {})

@Watch 装饰器接收两个参数：
path: string 被侦听的属性名；options?: WatchOptions={} options可以包含两个属性：

immediate?:boolean 侦听开始之后是否立即调用该回调函数；
deep?:boolean 被侦听的对象的属性被改变时，是否调用该回调函数；

发生在beforeCreate勾子之后，created勾子之前

<template>
  <div class="PropSync">
    <h1>child:{{child}}</h1>
    <input type="text" v-model="child"/>
  </div>
</template>
 
<script lang="ts">
import { Vue, Watch, Component } from 'vue-property-decorator';
 
@Component
export default class WatchPage extends Vue {
  private child = '';
 
  @Watch('child')
  onChildChanged(newValue: string, oldValue: string) {
    console.log(newValue);
    console.log(oldValue);
  }
}
</script>

6，@Emit(event?: string)

@Emit 装饰器接收一个可选参数，该参数是$Emit的第一个参数，充当事件名。如果没有提供这个参数，$Emit会将回调函数名的camelCase转为kebab-case，并将其作为事件名；
@Emit会将回调函数的返回值作为第二个参数，如果返回值是一个Promise对象，$emit会在Promise对象被标记为resolved之后触发；
@Emit的回调函数的参数，会放在其返回值之后，一起被$emit当做参数使用。

// 父组件
<template>
  <div class="">
    点击emit获取子组件的名字<br/>
    姓名:{{emitData.name}}
    <hr/>
    <EmitComponent sex='女' @add-to-count="returnPersons" @delemit="delemit"></EmitComponent>
  </div>
</template>
 
<script lang="ts">
import { Vue, Component } from 'vue-property-decorator';
import EmitComponent from '@/components/EmitComponent.vue';
 
@Component({
  components: { EmitComponent },
})
export default class EmitPage extends Vue {
  private emitData = { name: '我还没有名字' };
 
  returnPersons(data: any) {
    this.emitData = data;
  }
 
  delemit(event: MouseEvent) {
    console.log(this.emitData);
    console.log(event);
  }
}
</script>
 
// 子组件
<template>
  <div class="hello">
    子组件:
    <div v-if="person">
      姓名:{{person.name}}<br/>
      年龄:{{person.age}}<br/>
      性别:{{person.sex}}<br/>
    </div>
    <button @click="addToCount(person)">点击emit</button>
    <button @click="delToCount($event)">点击del emit</button>
  </div>
</template>
 
<script lang="ts">
import {
  Component, Vue, Prop, Emit,
} from 'vue-property-decorator';
 
type Person = {name: string; age: number; sex: string };
 
@Component
export default class PropComponent extends Vue {
  private name: string | undefined;
 
  private age: number | undefined;
 
  private person: Person = { name: '我是子组件的张三', age: 1, sex: '男' };
 
  @Prop(String) readonly sex: string | undefined;
 
  @Emit('delemit') private delEmitClick(event: MouseEvent) {}
 
  @Emit() // 如果此处不设置别名字,则默认使用下面的函数命名
  addToCount(p: Person) { // 此处命名如果有大写字母则需要用横线隔开  @add-to-count
    return this.person; // 此处不return,则会默认使用括号里的参数p;
  }
 
  delToCount(event: MouseEvent) {
    this.delEmitClick(event);
  }
}
</script>

7，@Ref(refKey?: string)

@Ref 装饰器接收一个可选参数，用来指向元素或子组件的引用信息。如果没有提供这个参数，会使用装饰器后面的属性名充当参数

<template>
  <div class="PropSync">
    <button @click="getRef()" ref="aButton">获取ref</button>
    <RefComponent name="names" ref="RefComponent"></RefComponent>
  </div>
</template>
 
<script lang="ts">
import { Vue, Component, Ref } from 'vue-property-decorator';
import RefComponent from '@/components/RefComponent.vue';
 
@Component({
  components: { RefComponent },
})
export default class RefPage extends Vue {
  @Ref('RefComponent') readonly RefC!: RefComponent;
  @Ref('aButton') readonly ref!: HTMLButtonElement;
  getRef() {
    console.log(this.RefC);
    console.log(this.ref);
  }
}
</script>

8.Provide/Inject ProvideReactive/InjectReactive

@Provide(key?: string | symbol) / @Inject(options?: { from?: InjecTKEy, default?: any } | InjectKey) decorator @ProvideReactive(key?: string | symbol) / @InjectReactive(options?: { from?: InjectKey, default?: any } | InjectKey) decorator

提供/注入装饰器,
key可以为string或者symbol类型,

相同点:Provide/ProvideReactive提供的数据,在内部组件使用Inject/InjectReactive都可取到不同点:
如果提供(ProvideReactive)的值被父组件修改，则子组件可以使用InjectReactive捕获此修改。

// 最外层组件
<template>
  <div class="">
    <H3>ProvideInjectPage页面</H3>
    <div>
      在ProvideInjectPage页面使用Provide,ProvideReactive定义数据,不需要props传递数据
      然后爷爷套父母,父母套儿子,儿子套孙子,最后在孙子组件里面获取ProvideInjectPage
      里面的信息
    </div>
    <hr/>
    <provideGrandpa></provideGrandpa> <!--爷爷组件-->
  </div>
</template>
 
<script lang="ts">
import {
  Vue, Component, Provide, ProvideReactive,
} from 'vue-property-decorator';
import provideGrandpa from '@/components/ProvideGParentComponent.vue';
 
@Component({
  components: { provideGrandpa },
})
export default class ProvideInjectPage extends Vue {
  @Provide() foo = Symbol('fooaaa');
 
  @ProvideReactive() fooReactive = 'fooReactive';
 
  @ProvideReactive('1') fooReactiveKey1 = 'fooReactiveKey1';
 
  @ProvideReactive('2') fooReactiveKey2 = 'fooReactiveKey2';
 
  created() {
    this.foo = Symbol('fooaaa111');
    this.fooReactive = 'fooReactive111';
    this.fooReactiveKey1 = 'fooReactiveKey111';
    this.fooReactiveKey2 = 'fooReactiveKey222';
  }
}
</script>
 
// ...provideGrandpa调用父母组件
<template>
  <div class="hello">
    <ProvideParentComponent></ProvideParentComponent>
  </div>
</template>
 
// ...ProvideParentComponent调用儿子组件
<template>
  <div class="hello">
    <ProvideSonComponent></ProvideSonComponent>
  </div>
</template>
 
// ...ProvideSonComponent调用孙子组件
<template>
  <div class="hello">
    <ProvideGSonComponent></ProvideGSonComponent>
  </div>
</template>
 
 
// 孙子组件<ProvideGSonComponent>,经过多层引用后,在孙子组件使用Inject可以得到最外层组件provide的数据哦
<template>
  <div class="hello">
    <h3>孙子的组件</h3>
    爷爷组件里面的foo:{{foo.description}}<br/>
    爷爷组件里面的fooReactive:{{fooReactive}}<br/>
    爷爷组件里面的fooReactiveKey1:{{fooReactiveKey1}}<br/>
    爷爷组件里面的fooReactiveKey2:{{fooReactiveKey2}}
    <span style="padding-left:30px;">=> fooReactiveKey2没有些key所以取不到哦</span>
  </div>
</template>
 
<script lang="ts">
import {
  Component, Vue, Inject, InjectReactive,
} from 'vue-property-decorator';
 
@Component
export default class ProvideGSonComponent extends Vue {
  @Inject() readonly foo!: string;
 
  @InjectReactive() fooReactive!: string;
 
  @InjectReactive('1') fooReactiveKey1!: string;
 
  @InjectReactive() fooReactiveKey2!: string;
}
</script>

demo地址:https://github.com/slailcp/vue-cli3/tree/master/src/pc-project/views/manage

到此这篇关于一文秒懂vue-property-decorator的文章就介绍到这了,更多相关vue-property-decorator内容请搜索编程网以前的文章或继续浏览下面的相关文章希望大家以后多多支持编程网！

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