Merge pull request #14372 from Snuffleupagus/BaseViewer-Lang

Move the /Lang handling into the `BaseViewer` (PR 14114 follow-up)

src/display/api.js

@@ -2406,6 +2406,8 @@ class WorkerTransport {
 
   #pagePromises = new Map();
 
+  #metadataPromise = null;
+
   constructor(messageHandler, loadingTask, networkStream, params) {
     this.messageHandler = messageHandler;
     this.loadingTask = loadingTask;
@@ -2530,6 +2532,7 @@ class WorkerTransport {
     Promise.all(waitOn).then(() => {
       this.commonObjs.clear();
       this.fontLoader.clear();
+      this.#metadataPromise = null;
       this._getFieldObjectsPromise = null;
       this._hasJSActionsPromise = null;
 
@@ -3063,7 +3066,7 @@ class WorkerTransport {
   }
 
   getMetadata() {
-    return this.messageHandler
+    return (this.#metadataPromise ||= this.messageHandler
       .sendWithPromise("GetMetadata", null)
       .then(results => {
         return {
@@ -3072,7 +3075,7 @@ class WorkerTransport {
           contentDispositionFilename: this._fullReader?.filename ?? null,
           contentLength: this._fullReader?.contentLength ?? null,
         };
-      });
+      }));
   }
 
   getMarkInfo() {
@@ -3098,6 +3101,7 @@ class WorkerTransport {
     if (!keepLoadedFonts) {
       this.fontLoader.clear();
     }
+    this.#metadataPromise = null;
     this._getFieldObjectsPromise = null;
     this._hasJSActionsPromise = null;
   }

web/app.js

@@ -809,7 +809,6 @@ const PDFViewerApplication = {
       const { container } = this.appConfig.errorWrapper;
       container.hidden = true;
     }
-    this.appConfig.viewerContainer.removeAttribute("lang");
 
     if (!this.pdfLoadingTask) {
       return;
@@ -1541,10 +1540,6 @@ const PDFViewerApplication = {
         `${(info.Producer || "-").trim()} / ${(info.Creator || "-").trim()}] ` +
         `(PDF.js: ${version || "-"})`
     );
-
-    if (info.Language) {
-      this.appConfig.viewerContainer.lang = info.Language;
-    }
     let pdfTitle = info?.Title;
 
     const metadataTitle = metadata?.get("dc:title");

web/base_viewer.js

@@ -486,10 +486,7 @@ class BaseViewer {
   /**
    * Currently only *some* permissions are supported.
    */
-  #initializePermissions(permissions, pdfDocument) {
-    if (pdfDocument !== this.pdfDocument) {
-      return; // The document was closed while the permissions resolved.
-    }
+  #initializePermissions(permissions) {
     if (!permissions) {
       return;
     }
@@ -603,9 +600,12 @@ class BaseViewer {
     // viewport for all pages
     Promise.all([firstPagePromise, permissionsPromise])
       .then(([firstPdfPage, permissions]) => {
+        if (pdfDocument !== this.pdfDocument) {
+          return; // The document was closed while the first page resolved.
+        }
         this._firstPageCapability.resolve(firstPdfPage);
         this._optionalContentConfigPromise = optionalContentConfigPromise;
-        this.#initializePermissions(permissions, pdfDocument);
+        this.#initializePermissions(permissions);
 
         const viewerElement =
           this._scrollMode === ScrollMode.PAGE ? null : this.viewer;
@@ -719,6 +719,15 @@ class BaseViewer {
 
         this.eventBus.dispatch("pagesinit", { source: this });
 
+        pdfDocument.getMetadata().then(({ info }) => {
+          if (pdfDocument !== this.pdfDocument) {
+            return; // The document was closed while the metadata resolved.
+          }
+          if (info.Language) {
+            this.viewer.lang = info.Language;
+          }
+        });
+
         if (this.defaultRenderingQueue) {
           this.update();
         }
@@ -789,6 +798,7 @@ class BaseViewer {
     // ... and reset the Scroll mode CSS class(es) afterwards.
     this._updateScrollMode();
 
+    this.viewer.removeAttribute("lang");
     // Reset all PDF document permissions.
     this.viewer.classList.remove(ENABLE_PERMISSIONS_CLASS);