How I can make @Model and @Emit work together in VueJs with Typescript?

Question

can anyone help me with decorators @Model and @Emit? I'm trying to change order on click in my component and used documentation from here: https://github.com/kaorun343/vue-property-decorator. Here is my code:

<template>
<button @click="onSortClick">Sort</button>
</template>  

<script lang="ts">
import Vue from "vue"; 
import { Emit, Componet, Model } from "vue-property-decorator";

export default class MyButton extends Vue {

    @Model("sort", { type: String, default: "none" }) readonly order!: string;

    @Emit("sort")
    onSortClick() {
        const nextSortOrder = {
                ascending: "descending",
                descending: "none",
                none: "ascending"
        };
        return nextSortOrder[this.order];
    }
}
</script>

But when I click the button, the value of variable "order" is not changing. Am I doing something wrong?

Answer 1

Yes, you are. There are a few things wrong here.

1. You need to import vue like this import { Vue, Component, Model, Emit } from 'vue-property-decorator;

2. The class needs to have an @Component decorator like this

@Component({/* Additional data can go in here */})
export default class MyButton extends Vue {}

3. This isn't how vue intended emitting of events to work. You cannot alter the value of order because it is a readonly property within the same file. If you place your button in another component like this

// ParentFile.vue

<template>
    <my-button @sort="order = $event"></my-button>
</template>

<script lang="ts">
  import { Component, Vue, Watch } from 'vue-property-decorator';
  import MyButton from '@/components/MyButton.vue';

  @Component({
    components: {
      MyButton
    }
  })
  export default class Home extends Vue {
    order = 'Wow';

    @Watch('order')
    orderChanged(newVal: string) {
      // eslint-disable-next-line no-console
      console.log(newVal); // order will change here
    }
  }
</script>

and listen to the emitted event as above then the order variable in the parent component will change but not the child.