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Internationalization & RTL

Reka UI support both LTR/RTL directions. Learn more about how to integrate internationalization with Radix.

Multi-Direction Support

Introduction

This documentation provides guidance on how to utilize multi-directional support in Reka UI with SSR support. Reka UI rely on Floating UI to position floating elements, which requires to be fed the current direction of the web app.

Radix components are LTR by default, but you are in control of what direction (only LTR, RTL, or both) you want to support. This section provides best practices to easily support RTL direction.

RTL

ConfigProvider is a wrapper component to provide global configurations, including the directionality of the web app.

When creating localized apps that require right-to-left (RTL) reading direction, you need to wrap your application with the ConfigProvider component to ensure all of the primitives adjust their behavior based on the dir prop.

To make all Reka UI RTL, wrap your entire App in ConfigProvider and pass the dir prop with the value rtl.

Add the following code to your app.vue or main layout component:

vue
<script setup lang="ts">
import { ConfigProvider } from 'reka-ui'
</script>

<template>
  <ConfigProvider dir="rtl">
    <slot />
  </ConfigProvider>
</template>

All Radix components that are wrapped in the provider inherit the dir attribute.

Dynamic Direction

To dynamically change the direction of Reka UI, we could leverage the useTextDirection composable and combine it with our ConfigProvider.

But first, we need to install the @vueuse/core package.

sh
$ npm add @vueuse/core

Then in your root Vue file:

vue
<script setup lang="ts">
import { computed } from 'vue'
import { ConfigProvider } from 'reka-ui'
import { useTextDirection } from '@vueuse/core'

const textDirection = useTextDirection()
const dir = computed(() => textDirection.value === 'rtl' ? 'rtl' : 'ltr')
</script>

<template>
  <ConfigProvider :dir="dir">
    <slot />
  </ConfigProvider>
</template>

To support SSR - when the server has no access to the html and its direction, set initialValue in useTextDirection.

vue
<script setup lang="ts">
import { ConfigProvider } from 'reka-ui'
import { useTextDirection } from '@vueuse/core'

const textDirection = useTextDirection({ initialValue: 'rtl' })
const dir = computed(() => textDirection.value === 'rtl' ? 'rtl' : 'ltr')
</script>

<template>
  <ConfigProvider :dir="dir">
    <slot />
  </ConfigProvider>
</template>
info

The dir prop doesn't support auto as a value, so we need an intermediate Ref to explicitly define the direction.

textDirection is a Ref, and by changing the value of it to either "ltr" or "rtl", the dir attribute on the html tag changes as well.

Internationalization

Some languages are written from LTR and others are written in RTL. In a multi-language web app, you need to configure directionality alongside the translations. This is a simplified guide on how to achieve that using radix-vue primitives.

But first, let's install some required packages.

Dependencies

We rely on VueI18n to manage different translations we want to support.

sh
$ npm add vue-i18n@9

Go ahead and add some translations for the word "hello" in different languages at main.ts.

ts
import { createApp } from 'vue'
import './style.css'
import App from './App.vue'
import { createI18n } from 'vue-i18n'

const messages = {
  en: {
    hello: 'Hello',
  },
  fa: {
    hello: 'درود',
  },
  ar: {
    hello: 'مرحبا',
  },
  ja: {
    hello: 'こんにちは',
  }
}

const i18n = createI18n({
  legacy: false, // you must set `false` to use the Composition API
  locale: 'en', // set default locale
  availableLocales: ['en', 'fa', 'ar', 'ja'],
  messages,
})

createApp(App)
  .use(i18n)
  .mount('#app')

Language Selector

After setting the translations and adding the vue-i18n plugin, we need a language selector in your app.vue. By changing the language using this radix select primitive:

  1. The translations are reactive to the new language
  2. The direction of the web app is reactive to the new language
vue
<script setup lang="ts">
import { ConfigProvider, SelectContent, SelectGroup, SelectItem, SelectItemIndicator, SelectItemText, SelectLabel, SelectPortal, SelectRoot, SelectScrollDownButton, SelectScrollUpButton, SelectTrigger, SelectValue, SelectViewport, } from 'reka-ui'
import { useTextDirection } from '@vueuse/core'

import { useI18n } from 'vue-i18n'
import { ref } from 'vue'

type LanguageInfo = {
  label: string
  value: string
  dir: 'ltr' | 'rtl'
}

const dir = useTextDirection({ initialValue: 'ltr' })
const { locale } = useI18n()

const selectedLanguage = ref<string>()

const languages: LanguageInfo[] = [
  { label: 'English', value: 'en', dir: 'ltr' },
  { label: 'Persian', value: 'fa', dir: 'rtl' },
  { label: 'Arabic', value: 'ar', dir: 'rtl' },
  { label: 'Japanese', value: 'ja', dir: 'ltr' },
]

function selectLanguage(newLanguage: string) {
  const langInfo = languages.find(item => item.value === newLanguage)

  if (!langInfo)
    return

  dir.value = langInfo.dir
  locale.value = langInfo.value
}
</script>

<template>
  <ConfigProvider :dir="dir">
    <div class="flex flex-col max-w-[1400px] mx-auto gap-y-[8rem] justify-center items-center p-10">
      <div class="text-2xl">
        👋 {{ $t("hello") }}
      </div>
      <div class="text-2xl">
        HTML is in <span class="text-bold text-purple-500">{{ dir }}</span> mode
      </div>

      <SelectRoot
        v-model="selectedLanguage"
        @update:model-value="selectLanguage"
      >
        <SelectTrigger
          class="inline-flex min-w-[160px] items-center justify-between rounded px-[15px] text-[13px] leading-none h-[35px] gap-[5px] bg-white text-grass11 shadow-[0_2px_10px] shadow-black/10 hover:bg-mauve3 focus:shadow-[0_0_0_2px] focus:shadow-black data-[placeholder]:text-green9 outline-none"
          aria-label="Customize options"
        >
          <SelectValue placeholder="Select a language..." />
          <Icon
            icon="radix-icons:chevron-down"
            class="h-3.5 w-3.5"
          />
        </SelectTrigger>

        <SelectPortal>
          <SelectContent
            class="min-w-[160px] bg-white rounded shadow-[0px_10px_38px_-10px_rgba(22,_23,_24,_0.35),_0px_10px_20px_-15px_rgba(22,_23,_24,_0.2)] will-change-[opacity,transform] data-[side=top]:animate-slideDownAndFade data-[side=right]:animate-slideLeftAndFade data-[side=bottom]:animate-slideUpAndFade data-[side=left]:animate-slideRightAndFade z-[100]"
            :side-offset="5"
          >
            <SelectScrollUpButton
              class="flex items-center justify-center h-[25px] bg-white text-violet11 cursor-default"
            >
              <Icon icon="radix-icons:chevron-up" />
            </SelectScrollUpButton>

            <SelectViewport class="p-[5px]">
              <SelectLabel class="px-[25px] text-xs leading-[25px] text-mauve11">
                Languages
              </SelectLabel>
              <SelectGroup>
                <SelectItem
                  v-for="(option, index) in languages"
                  :key="index"
                  class="text-[13px] leading-none text-grass11 rounded-[3px] flex items-center h-[25px] pr-[35px] pl-[25px] relative select-none data-[disabled]:text-mauve8 data-[disabled]:pointer-events-none data-[highlighted]:outline-none data-[highlighted]:bg-green9 data-[highlighted]:text-green1"
                  :value="option.value"
                >
                  <SelectItemIndicator class="absolute left-0 w-[25px] inline-flex items-center justify-center">
                    <Icon icon="radix-icons:check" />
                  </SelectItemIndicator>
                  <SelectItemText>
                    {{ option.label }}
                  </SelectItemText>
                </SelectItem>
              </SelectGroup>
            </SelectViewport>

            <SelectScrollDownButton
              class="flex items-center justify-center h-[25px] bg-white text-violet11 cursor-default"
            >
              <Icon icon="radix-icons:chevron-down" />
            </SelectScrollDownButton>
          </SelectContent>
        </SelectPortal>
      </SelectRoot>
    </div>
  </ConfigProvider>
</template>