First commit

frontend/app/middleware/open-article.ts

@@ -0,0 +1,36 @@
+/* Before a reader route draws anything — /wiki/<slug> for an article,
+   /wiki/<lang>/<slug> for one of its language versions — put the document it
+   names on the library's shelf. On the server that is what lets the page in
+   view be written out in the first HTML; on the client it is what the stack of
+   open pages grows from, and the title the page is filed under. A page that is
+   already on the shelf comes straight off it and is re-read in the background
+   — so an edit made elsewhere still shows up when you turn to it. */
+
+/** How a document is filed in the tab stack: which article, which language. */
+function tabMeta(article: { slug: string; language?: string; baseSlug?: string | null }) {
+  return { lang: article.language ?? 'en', identity: article.baseSlug || article.slug }
+}
+
+export default defineNuxtRouteMiddleware(async (to) => {
+  const loc = parseReaderPath(to.path)
+  if (!loc) return
+
+  /* taken before any await, while the app context is certainly at hand */
+  const library = useArticleLibrary()
+  const tabs = useArticleTabs()
+
+  const onShelf = loc.lang
+    ? library.getVersion(loc.identity, loc.lang)
+    : library.get(loc.identity)
+  if (onShelf) {
+    tabs.ensureTab(onShelf.slug, onShelf.title, tabMeta(onShelf))
+    library.revalidate(loc.identity, loc.lang ?? undefined)
+    return
+  }
+
+  const article = loc.lang
+    ? await library.loadVersion(loc.identity, loc.lang)
+    : await library.load(loc.identity)
+
+  if (article) tabs.ensureTab(article.slug, article.title, tabMeta(article))
+})