why are getter/setter not working properly in vue typescript class component

user_11155087 0
Viewed 1478

I'm new to vue.js and I'm wondering why the following code is not working as expected:

<template>
  <page-layout>
    <h1>Hello, Invoicer here</h1>
    <form class="invoicer-form">
      <div><label><span>Datum</span><input v-model="date" v-on:change="dateChanged" /></label></div>
      <div><label><span>Zeitraum</span><input v-model="timespan" /></label></div>
    </form>
  </page-layout>
</template>

<script lang="ts">
    import { Component, Prop, Vue } from 'vue-property-decorator'
    import PageLayout from '@/components/layout/PageLayout.vue'
    import dayjs from 'dayjs'
    import customParseFormat from 'dayjs/plugin/customParseFormat'

    @Component({
        components: { PageLayout }
    })
    export default class Invoicer extends Vue {

        date = ''
        _timespan = ''

        beforeCreate(): void {
            dayjs.extend(customParseFormat)
        }

        dateChanged(): void {
            const format = 'DD.MM.YYYY'
            const date = dayjs(this.date, format)
            if (date.isValid()) {
                if (!this.timespan) {
                    const from = date.subtract(1, 'month').startOf('month').format(format)
                    const until = date.endOf('month').format(format)
                    this.timespan = `${from} - ${until}`
                }
            }
        }

        get timespan(): string {
            return this._timespan
        }

        set timespan(value: string) {
            this._timespan = value
        }

    }
</script>

when I change the 'Datum' the dateChanged()-method is executed and sets the _timespan-property with its setter. But the GUI won't be updated. If I remove the setter/getter and use the _timespan`-property directly, everything works fine. I really think it should also work with the setter/getter or in other therms, computed property, shouldn't it?

vue-class-components vue.js typescript
1 Answers

Ok, I got it working. The main problem is, the defined class isn't existing at all on runtime. The vue-class-component plugin just use the definition and creates a VueComponent based on it. So this isn't what it it seems to be. The plugin adds properties as data properties, getter/setter as computed properties. But it seems like it doesn't add properties starting with an underscore. Like Owl mentioned in his comment, this is not an vue-class-compnent issue but a documented vue behavior: https://v2.vuejs.org/v2/api/#data Anyhow, if I change the code as follows, it works:

    @Component({
        components: { PageLayout }
    })
    export default class Invoicer extends Vue {

        date = ''
        timesspan = ''

        beforeCreate(): void {
            dayjs.extend(customParseFormat)
        }

        dateChanged(): void {
            console.log("badsfls")
            const format = 'DD.MM.YYYY'
            const date = dayjs(this.date, format)
            if (date.isValid()) {
                if (!this.timespan) {
                    const from = date.subtract(1, 'month').startOf('month').format(format)
                    const until = date.endOf('month').format(format)
                    this.timespan = `${from} - ${until}`
                }
            }
        }

        get timespan(): string {
            return this.timesspan
        }

        set timespan(value: string) {
            this.timesspan = value
        }

    }

Giving the property an other name without leading underscore does the trick.

But I think I won't use the vue-class-component plugin anymore. It is too much around the corner thinking for me.

user_111550870
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