Variables in vue-i18n-next do not work when using composition API in setup script of Vue 3.2

Question

In a vue 3.2 project, I'm using the vue-i18n-next v9, composition api and <script setup> methods.

I'm trying to create a translation message using some variables indicated by {}'s. For example

export default {
    conclusion: `After reviewing the above invoices, it was found that there is currently a difference of about {total_difference} in your {advantage_type} on the whole of these invoices.`
}

My vue component looks like this:

<script setup>
    import { ref } from 'vue';
    import { useI18n } from 'vue-i18n';
    import { getHumanPrice } from '@/utils/helpers';

    const { t } = useI18n();

    const total_difference = ref(2000);

    const conclusion = computed(() => {
        return t('conclusion', 1, {
            total_difference: total_difference.value
            advantage_type: total_difference.value >= 0 ? t('advantage', 1).toLowerCase() : t('disadvantage', 1).toLowerCase(),
        });
    });
</script>

The result is a string without a variable partAfter reviewing the above invoices, I found that there are currently approximately differences between these invoices and your

Previously, when using vue-i18n-next package and options api in vue 2, there was no problem and strings and variables were formed correctly. The code is as follows:

<script>
    export default: {
        data() {
            return {
                total_difference: 2000,
            }
        },
        computed: {
            conclusion() {
                return this.$tc('conclusion', 1, {
                    total_difference: this.$filters.getHumanPrice(this.total_difference, 2),
                    advantage_type: this.total_difference >= 0 ? t('advantage', 1).toLowerCase() : t('disadvantage', 1).toLowerCase(),
                });
            },
        }
    }
</script>

The output is After reviewing the above invoices, I found that there is currently a difference of approximately $2500,00 in your overall advantage on these invoices.

Any idea what has changed with the composition api methods or what I might be doing wrong?

Answer 1

$tc provides a plural translation, its direct replacement is tc:

tc('conclusion', 1, { ... })

t is a universal translation function, and although it allows plurals, it cannot accept named interpolated objects as parameters, since there may be other options, which in this case would be ：

t('conclusion', 1, { named: { ... } })