Vue2 使用Typescript 使用vue-property-decorator的简单介绍

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