Formatting an initial/passed value about vue-currency-input HOT 4 CLOSED

<template>
    <el-input v-model="internalValue" v-currency="options" class="currency-input"/>
</template>
<script>
    export default {
        props: ['value', 'currency'],
        components: {},
        data: function () {
            return {
                options: {
                    locale: 'el',
                    currency: this.currency,
                    distractionFree: true,
                    validateOnInput: false
                },
                internalValue: null
            }
        },
        watch: {
            value(newValue, oldValue) {
                // only format when value is set programmatically, not typed in  by user
                if (oldValue == null && newValue != null && this.internalValue == null) {
                    this.internalValue = this.formatCurrency(newValue, this.currency, this.options.locale)
                } else {
                    this.internalValue = newValue
                }
            },
            internalValue(newValue) {
                this.$emit('input', this.$parseCurrency(newValue, this.options.locale, this.options.currency))
            }
        },
        methods: {
            formatCurrency(num, currency, locale) {
                if (typeof num === 'string') {
                    return num
                } else if (num && typeof num === 'number') {
                    return new Intl.NumberFormat(locale, { style: 'currency', currency }).format(num)
                }
                return null
            }
        }
    }
</script>