vue-i18n / general / useI18n

Function: useI18n()

Call Signature

function useI18n<Options>(options?): Composer<NonNullable<Options["messages"]>, NonNullable<Options["datetimeFormats"]>, NonNullable<Options["numberFormats"]>, Options["locale"] extends unknown ? string : Options["locale"]>;

Type Parameters

Type Parameter

Default type

Options extends UseI18nOptions<{ datetime: IntlDateTimeFormat; message: DefaultLocaleMessageSchema; number: IntlNumberFormat; }, string, ComposerOptions<{ datetime: IntlDateTimeFormat; message: DefaultLocaleMessageSchema; number: IntlNumberFormat; }, string, string, string, string, LocaleMessage<VueMessageType>, IntlDateTimeFormat, IntlNumberFormat, LocaleMessages<LocaleMessage<VueMessageType>, string, VueMessageType>, IntlDateTimeFormats<IntlDateTimeFormat, string>, IntlNumberFormats<IntlNumberFormat, string>>>

UseI18nOptions<{ datetime: IntlDateTimeFormat; message: DefaultLocaleMessageSchema; number: IntlNumberFormat; }, string, ComposerOptions<{ datetime: IntlDateTimeFormat; message: DefaultLocaleMessageSchema; number: IntlNumberFormat; }, string, string, string, string, LocaleMessage<VueMessageType>, IntlDateTimeFormat, IntlNumberFormat, LocaleMessages<LocaleMessage<VueMessageType>, string, VueMessageType>, IntlDateTimeFormats<IntlDateTimeFormat, string>, IntlNumberFormats<IntlNumberFormat, string>>>

Parameters

Parameter	Type
options?	Options

Returns

Composer<NonNullable<Options["messages"]>, NonNullable<Options["datetimeFormats"]>, NonNullable<Options["numberFormats"]>, Options["locale"] extends unknown ? string : Options["locale"]>

Call Signature

function useI18n<Schema, Locales, Options>(options?): Composer<NonNullable<Options["messages"]>, NonNullable<Options["datetimeFormats"]>, NonNullable<Options["numberFormats"]>, NonNullable<Options["locale"]>>;

Use Composition API for Vue I18n

Type Parameters

Type Parameter	Default type	Description
Schema	LocaleMessage<VueMessageType>	The i18n resources (messages, datetimeFormats, numberFormats) schema, default LocaleMessage
Locales	"en-US"	The locales of i18n resource schema, default en-US
Options extends UseI18nOptions<SchemaParams<Schema, VueMessageType>, LocaleParams<Locales>, ComposerOptions<SchemaParams<Schema, VueMessageType>, LocaleParams<Locales>, LocaleParams<Locales> extends object ? M : LocaleParams<Locales> extends string ? string & LocaleParams<Locales> : string, LocaleParams<Locales> extends object ? D : LocaleParams<Locales> extends string ? string & LocaleParams<Locales> : string, LocaleParams<Locales> extends object ? N : LocaleParams<Locales> extends string ? string & LocaleParams<Locales> : string, SchemaParams<Schema, VueMessageType> extends object ? M : LocaleMessage<VueMessageType>, SchemaParams<Schema, VueMessageType> extends object ? D : IntlDateTimeFormat, SchemaParams<Schema, VueMessageType> extends object ? N : IntlNumberFormat, LocaleMessages<SchemaParams<Schema, VueMessageType> extends object ? M : LocaleMessage<VueMessageType>, LocaleParams<Locales> extends object ? M : LocaleParams<Locales> extends string ? string & LocaleParams<Locales> : string, VueMessageType>, IntlDateTimeFormats<SchemaParams<Schema, VueMessageType> extends object ? D : IntlDateTimeFormat, LocaleParams<Locales> extends object ? D : LocaleParams<Locales> extends string ? string & LocaleParams<Locales> : string>, IntlNumberFormats<SchemaParams<Schema, VueMessageType> extends object ? N : IntlNumberFormat, LocaleParams<Locales> extends object ? N : LocaleParams<Locales> extends string ? string & LocaleParams<Locales> : string>>>	UseI18nOptions<SchemaParams<Schema, VueMessageType>, LocaleParams<Locales>, ComposerOptions<SchemaParams<Schema, VueMessageType>, LocaleParams<Locales>, LocaleParams<Locales> extends object ? M : LocaleParams<Locales> extends string ? string & LocaleParams<Locales> : string, LocaleParams<Locales> extends object ? D : LocaleParams<Locales> extends string ? string & LocaleParams<Locales> : string, LocaleParams<Locales> extends object ? N : LocaleParams<Locales> extends string ? string & LocaleParams<Locales> : string, SchemaParams<Schema, VueMessageType> extends object ? M : LocaleMessage<VueMessageType>, SchemaParams<Schema, VueMessageType> extends object ? D : IntlDateTimeFormat, SchemaParams<Schema, VueMessageType> extends object ? N : IntlNumberFormat, LocaleMessages<SchemaParams<Schema, VueMessageType> extends object ? M : LocaleMessage<VueMessageType>, LocaleParams<Locales> extends object ? M : LocaleParams<Locales> extends string ? string & LocaleParams<Locales> : string, VueMessageType>, IntlDateTimeFormats<SchemaParams<Schema, VueMessageType> extends object ? D : IntlDateTimeFormat, LocaleParams<Locales> extends object ? D : LocaleParams<Locales> extends string ? string & LocaleParams<Locales> : string>, IntlNumberFormats<SchemaParams<Schema, VueMessageType> extends object ? N : IntlNumberFormat, LocaleParams<Locales> extends object ? N : LocaleParams<Locales> extends string ? string & LocaleParams<Locales> : string>>>	-

Parameters

Parameter	Type	Description
options?	Options	An options, see UseI18nOptions

Returns

Composer<NonNullable<Options["messages"]>, NonNullable<Options["datetimeFormats"]>, NonNullable<Options["numberFormats"]>, NonNullable<Options["locale"]>>

Composer instance

Remarks

This function is mainly used by setup.

If options are specified, Composer instance is created for each component and you can be localized on the component.

If options are not specified, you can be localized using the global Composer.

Example

case: Component resource base localization

<template>
  <form>
    <label>{{ t('language') }}</label>
    <select v-model="locale">
      <option value="en">en</option>
      <option value="ja">ja</option>
    </select>
  </form>
  <p>message: {{ t('hello') }}</p>
</template>

<script>
import { useI18n } from 'vue-i18n'

export default {
 setup() {
   const { t, locale } = useI18n({
     locale: 'ja',
     messages: {
       en: { ... },
       ja: { ... }
     }
   })
   // Something to do ...

   return { ..., t, locale }
 }
}
</script>

Vue I18n Composition