feat(presenter): make i18n locale extractable from url

presenter/renderer/+config.ts

@@ -2,7 +2,7 @@
 export default {
   clientRouting: true,
   prefetchStaticAssets: 'viewport',
-  passToClient: ['pageProps', /* 'urlPathname', */ 'routeParams'],
+  passToClient: ['pageProps', /* 'urlPathname', */ 'routeParams', 'locale'],
   meta: {
     title: {
       // Make the value of `title` available on both the server- and client-side

presenter/renderer/+onBeforeRoute.ts

@@ -0,0 +1,16 @@
+import { PageContext } from 'vike/types'
+
+import { extractLocale } from '#src/locales'
+
+export function onBeforeRoute(pageContext: PageContext) {
+  const { urlWithoutLocale, locale } = extractLocale(pageContext.urlPathname)
+
+  return {
+    pageContext: {
+      // Make `locale` available as `pageContext.locale`
+      locale,
+      // Vike's router will use pageContext.urlLogical instead of pageContext.urlOriginal
+      urlLogical: urlWithoutLocale,
+    },
+  }
+}

presenter/renderer/+onPrerenderStart.ts

@@ -0,0 +1,32 @@
+import { PageContextServer } from 'vike/types'
+
+import { locales } from '#src/locales'
+
+export { onPrerenderStart }
+
+function onPrerenderStart(prerenderContext: { pageContexts: PageContextServer[] }): {
+  prerenderContext: {
+    pageContexts: PageContextServer[]
+  }
+} {
+  const storePageContexts: PageContextServer[] = []
+  prerenderContext.pageContexts.forEach((pageContext) => {
+    // Duplicate pageContext for each locale
+    locales.forEach((locale) => {
+      // Localize URL
+      let { urlOriginal } = pageContext
+      urlOriginal = `/${locale}${urlOriginal}`
+      storePageContexts.push({
+        ...pageContext,
+        urlOriginal,
+        // Set pageContext.locale
+        locale,
+      })
+    })
+  })
+  return {
+    prerenderContext: {
+      pageContexts: storePageContexts,
+    },
+  }
+}

presenter/renderer/app.ts

@@ -9,6 +9,7 @@ import { createApolloClient } from '#plugins/apollo'
 import i18n from '#plugins/i18n'
 import pinia from '#plugins/pinia'
 import CreateVuetify from '#plugins/vuetify'
+import { locales } from '#src/locales'
 import AuthService from '#src/services/AuthService'
 import { useAuthStore } from '#stores/authStore'
 
@@ -25,6 +26,7 @@ function createApp(pageContext: PageContext, isClient = true) {
     data: () => ({
       Page: markRaw(pageContext.Page),
       pageProps: markRaw(pageContext.pageProps || {}),
+      locale: markRaw(pageContext.locale || {}),
       isClient,
     }),
     created() {
@@ -64,13 +66,18 @@ function createApp(pageContext: PageContext, isClient = true) {
       Object.assign(pageContextReactive, pageContext)
       rootComponent.Page = markRaw(pageContext.Page)
       rootComponent.pageProps = markRaw(pageContext.pageProps || {})
+      rootComponent.locale = markRaw(pageContext.locale || {})
     },
   })
 
   const pageContextReactive = reactive(pageContext)
 
   setPageContext(app, pageContextReactive)
 
+  if (pageContext.locale && locales.includes(pageContext.locale)) {
+    i18n.global.locale.value = pageContext.locale
+  }
+
   return { app, i18n }
 }
 

presenter/renderer/plugins/i18n.ts

@@ -1,14 +1,15 @@
 import { createI18n } from 'vue-i18n'
 import { de as vuetifyDe, en as vuetifyEn } from 'vuetify/locale'
 
+import { localeDefault, fallbackLocale } from '#src/locales'
 import de from '#src/locales/de.json'
 import en from '#src/locales/en.json'
 
 export default createI18n({
   legacy: false, // Vuetify does not support the legacy mode of vue-i18n
   globalInjection: true,
-  locale: 'de',
-  fallbackLocale: 'en',
+  locale: localeDefault,
+  fallbackLocale,
   messages: {
     de: {
       $vuetify: vuetifyDe,

presenter/scripts/tests/mock.vikePageContext.ts

@@ -9,5 +9,6 @@ config.global.provide = {
     routeParams: {
       code: 'my-code',
     },
+    locale: 'de',
   },
 }

presenter/src/components/language/LanguageSelector.test.ts

@@ -1,6 +1,8 @@
 import { mount } from '@vue/test-utils'
 import { describe, it, expect, beforeEach } from 'vitest'
 
+import i18n from '#plugins/i18n'
+
 import LanguageSelector from './LanguageSelector.vue'
 
 describe('LanguageSelector', () => {
@@ -10,12 +12,24 @@ describe('LanguageSelector', () => {
     })
   }
   let wrapper: ReturnType<typeof Wrapper>
+  let vSelect: ReturnType<typeof wrapper.findComponent>
 
   beforeEach(() => {
     wrapper = Wrapper()
+    vSelect = wrapper.findComponent({ name: 'v-select' })
   })
 
   it('renders', () => {
     expect(wrapper.element).toMatchSnapshot()
   })
+
+  describe('switch locale', () => {
+    beforeEach(async () => {
+      await vSelect.setValue('en')
+    })
+
+    it('to en', () => {
+      expect(i18n.global.locale.value).toBe('en')
+    })
+  })
 })

presenter/src/components/language/LanguageSelector.vue

@@ -29,11 +29,9 @@
 <script lang="ts" setup>
 import { ref } from 'vue'
 
-// TODO better place? maybe locales folder?
-const languages = ref([
-  { locale: 'de', title: 'Deutsch' },
-  { locale: 'en', title: 'English' },
-])
+import { localizedLocale } from '#src/locales'
+
+const languages = ref(localizedLocale)
 </script>
 
 <style lang="scss">

presenter/src/locales/index.ts

@@ -0,0 +1,25 @@
+export type LocaleCode = 'de' | 'en'
+export const locales: LocaleCode[] = ['de', 'en']
+export const localeDefault = 'de'
+export const fallbackLocale = 'en'
+export const localizedLocale = [
+  { locale: 'de', title: 'Deutsch' },
+  { locale: 'en', title: 'English' },
+]
+
+export function extractLocale(url: string) {
+  const urlPaths = url.split('/')
+  let locale: LocaleCode
+  let urlWithoutLocale
+  // We remove the URL locale, for example `/de/about` => `/about`
+  const firstPath = urlPaths[1] as LocaleCode
+  if (locales.includes(firstPath)) {
+    locale = firstPath
+    urlWithoutLocale = '/' + urlPaths.slice(2).join('/')
+  } else {
+    locale = localeDefault
+    urlWithoutLocale = url
+  }
+
+  return { locale, urlWithoutLocale }
+}

presenter/types/PageContext.d.ts

@@ -1,3 +1,4 @@
+import { LocaleCode } from '#src/locales'
 import { Page } from '#types/Page'
 import { PageProps } from '#types/PageProps'
 
@@ -11,6 +12,7 @@ declare global {
       }
       Page: Page
       pageProps?: PageProps
+      locale?: LocaleCode
     }
   }
 }

presenter/vite.config.ts

@@ -17,7 +17,7 @@ const config: UserConfig = {
     !isStorybook() && vike({ prerender: true }), // SSR only when storybook is not running
     vueI18n({
       ssr: true,
-      include: path.resolve(__dirname, './src/locales/**'),
+      include: path.resolve(__dirname, './src/locales/**.json'),
       jitCompilation: false,
     }),
     checker({