From fd1dd7c695bb5b6be9a833b8f7851aa252983022 Mon Sep 17 00:00:00 2001
From: pengzhanbo <volodymyr@foxmail.com>
Date: Thu, 5 Mar 2026 14:42:48 +0800
Subject: [PATCH] feat(theme): add lang switch to update html lang attr (#867)

---
 theme/src/client/composables/layout.ts | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/theme/src/client/composables/layout.ts b/theme/src/client/composables/layout.ts
index f17e02b1..21133e7e 100644
--- a/theme/src/client/composables/layout.ts
+++ b/theme/src/client/composables/layout.ts
@@ -90,6 +90,7 @@ export function registerWatchers() {
     }, { passive: true })
   }
 
+  const { lang } = useData()
   const route = useRoute()
   const { disableSidebar, toggleSidebarCollapse } = useSidebarControl()
   watch(() => route.path, () => {
@@ -97,5 +98,11 @@ export function registerWatchers() {
     toggleSidebarCollapse(false)
   })
 
+  if (inBrowser) {
+    watch(lang, (newLang) => {
+      document.documentElement.lang = newLang
+    }, { immediate: true })
+  }
+
   useCloseSidebarOnEscape()
 }