provide I18nT to simplify element translation

spx-gui/.eslintrc.cjs

@@ -28,7 +28,8 @@ module.exports = {
           // These rules will match components in both kebab-case and CamelCase
           'router-view',
           'router-link',
-          'v-.*' // for Vue Konva components
+          'v-.*', // for Vue Konva components
+          'I18nT'
         ]
       }
     ],

spx-gui/src/components/project/ProjectPublishedModal.vue

@@ -18,20 +18,6 @@ const emit = defineEmits<{
 const projectPageRoute = computed(() => getProjectPageRoute(props.project.owner!, props.project.name!))
 const projectPageLink = computed(() => `${location.origin}${projectPageRoute.value}`)
 
-// TODO: support vnode as i18n message to simplify such case
-const preLinkText = {
-  en: 'Visit ',
-  zh: '访问'
-}
-const linkText = {
-  en: 'project page',
-  zh: '项目主页'
-}
-const postLinkText = {
-  en: ', or copy the link below to share the project with others.',
-  zh: '，或者复制下方链接将项目分享给其他人。'
-}
-
 const handleCopy = useMessageHandle(
   () => navigator.clipboard.writeText(projectPageLink.value),
   { en: 'Failed to copy link to clipboard', zh: '分享链接复制到剪贴板失败' },
@@ -47,8 +33,15 @@ const handleCopy = useMessageHandle(
     @update:visible="emit('cancelled')"
   >
     <div class="desc">
-      {{ $t(preLinkText) }}<UILink target="_blank" :href="projectPageRoute">{{ $t(linkText) }}</UILink
-      >{{ $t(postLinkText) }}
+      <I18nT>
+        <template #en>
+          Visit <UILink target="_blank" :href="projectPageRoute">project page</UILink>, or copy the link below to share
+          the project with others.
+        </template>
+        <template #zh>
+          访问<UILink target="_blank" :href="projectPageRoute">项目主页</UILink>，或者复制下方链接将项目分享给其他人。
+        </template>
+      </I18nT>
     </div>
     <div class="link-wrapper">
       <UITextInput :value="projectPageLink" :readonly="true" @focus="$event.target.select()" />

spx-gui/src/pages/community/search.vue

@@ -1,12 +1,17 @@
 <template>
   <CommunityHeader>
-    <template v-if="titleForResult != null">
-      <!-- TODO: support vnode as i18n message to simplify such case -->
-      {{ $t(titleForResult.prefix) }}<span class="keyword">{{ keyword }}</span
-      >{{ $t(titleForResult.suffix) }}
-    </template>
+    <I18nT v-if="queryRet.data.value != null">
+      <template #en>
+        Found {{ queryRet.data.value?.total }} projects for "<span class="keyword">{{ keyword }}</span
+        >"
+      </template>
+      <template #zh>
+        找到 {{ queryRet.data.value?.total }} 个关于“<span class="keyword">{{ keyword }}</span
+        >”的项目
+      </template>
+    </I18nT>
     <template v-else>
-      {{ $t(titleForNoResult) }}
+      {{ $t({ en: 'Search projects', zh: '搜索项目' }) }}
     </template>
     <template #options>
       <label>
@@ -121,24 +126,6 @@ const queryRet = useQuery(() => listProject(listParams.value), {
   en: 'Failed to search projects',
   zh: '搜索项目失败'
 })
-
-const titleForResult = computed(() => {
-  if (queryRet.data.value == null) return null
-  return {
-    prefix: {
-      en: `Found ${queryRet.data.value?.total} projects for "`,
-      zh: `找到 ${queryRet.data.value?.total} 个关于“`
-    },
-    suffix: {
-      en: '"',
-      zh: '”的项目'
-    }
-  }
-})
-const titleForNoResult = computed(() => ({
-  en: 'Search projects',
-  zh: '搜索项目'
-}))
 </script>
 
 <style lang="scss" scoped>

spx-gui/src/utils/i18n/README.md

@@ -24,9 +24,11 @@ i18n.setLang('zh')
 ### Do translation in template of SFC
 
 ```vue
-<button>
-  {{$t({ en: 'Sign in', zh: '登录' })}}
-</button>
+<template>
+  <button>
+    {{ $t({ en: 'Sign in', zh: '登录' }) }}
+  </button>
+</template>
 ```
 
 ### Do translation in setup script
@@ -39,6 +41,17 @@ const { t } = useI18n()
 const signoutText = t({ en: 'Sign out', zh: '登出' })
 ```
 
+### Translate complex elements in template of SFC
+
+```vue
+<template>
+  <I18nT>
+    <template #en>Please <a :href="link">sign in</a>.</template>
+    <template #zh>请<a :href="link">登录</a>。</template>
+  </I18nT>
+</template>
+```
+
 ### Locale Message Functions
 
 Locale-message-functions are functions that return locale message. It is useful when extra information is needed when constructing locale messages. For example:

spx-gui/src/utils/i18n/index.ts

@@ -2,7 +2,16 @@
  * @desc Simple i18n tool for vue
  */
 
-import { inject, type App, type InjectionKey, type ObjectPlugin, ref, type Ref } from 'vue'
+import {
+  inject,
+  type App,
+  type InjectionKey,
+  type ObjectPlugin,
+  ref,
+  type Ref,
+  type SetupContext,
+  type SlotsType
+} from 'vue'
 
 export type Lang = 'en' | 'zh'
 
@@ -26,6 +35,9 @@ declare module '@vue/runtime-core' {
   interface ComponentCustomProperties {
     $t: TranslateFn
   }
+  interface GlobalComponents {
+    I18nT: typeof T
+  }
 }
 
 const injectKey: InjectionKey<I18n> = Symbol('i18n')
@@ -57,16 +69,38 @@ export class I18n implements ObjectPlugin<[]> {
   install(app: App<unknown>) {
     app.provide(injectKey, this)
     app.config.globalProperties.$t = this.t
+    app.component('I18nT', T as any)
   }
 }
 
+// NOTE: `T` (also known as `I18nT`) is a suitable choice for translating complex content within templates in Single File Component (SFC).
+// It relies on a straightforward mechanism and integrates well with SFC features such as scoped styles.
+// If we decide to externalize locale messages from components into separate locale data in the future, we need to:
+// 1. Provide support for locale messages of type `VNode`.
+// 2. Adjust component code to properly handle potential issues with SFC features like scoped styles.
+
+/**
+ * Translate component. Use slot with lang as key to provide translated content. e.g.,
+ * ```html
+ * <I18nT>
+ *   <template #en>English</template>
+ *   <template #zh>中文</template>
+ * </I18nT>
+ * ```
+ */
+function T(_props: unknown, { slots }: SetupContext<unknown, SlotsType<Record<Lang, any>>>) {
+  const i18n = inject(injectKey)
+  if (i18n == null) throw new Error('i18n not installed')
+  return slots[i18n.lang.value]?.()
+}
+
 export function createI18n(config: I18nConfig) {
   return new I18n(config)
 }
 
 export function useI18n() {
   const i18n = inject(injectKey)
-  if (i18n == null) throw new Error('i18n not used')
+  if (i18n == null) throw new Error('i18n not installed')
   return i18n
 }
 

spx-gui/src/utils/utils.ts

@@ -155,6 +155,8 @@ export function memoizeAsync<T extends (...args: any) => Promise<unknown>>(
   }) as T
 }
 
+// TODO: we may move these `humanizeX` functions to i18n module as exposed helpers
+
 /** Convert time string to human-friendly format, e.g., "3 days ago" */
 export function humanizeTime(time: string): LocaleMessage {
   const t = dayjs(time)