Adding new errorback and code to display error messages.

src/core.js

@@ -63,6 +63,10 @@ var Page = (function pagePage() {
     };
     this.xref = xref;
     this.ref = ref;
+
+    this.ctx = null;
+    this.callback = null;
+    this.errorback = null;
   }
 
   constructor.prototype = {
@@ -165,8 +169,10 @@ var Page = (function pagePage() {
           try {
             self.display(gfx, self.callback);
           } catch (e) {
-            if (self.callback) self.callback(e.toString());
-            throw e;
+            if (self.errorback)
+              self.errorback(e);
+            else
+              throw e;
           }
         });
       };
@@ -303,9 +309,10 @@ var Page = (function pagePage() {
       }
       return links;
     },
-    startRendering: function pageStartRendering(ctx, callback)  {
+    startRendering: function pageStartRendering(ctx, callback, errorback)  {
       this.ctx = ctx;
       this.callback = callback;
+      this.errorback = errorback;
 
       this.startRenderingTime = Date.now();
       this.pdf.startRendering(this);
@@ -599,6 +606,14 @@ var PDFDoc = (function pdfDoc() {
         }
       }.bind(this));
 
+      messageHandler.on('page_error', function pdfDocError(data) {
+        var page = this.pageCache[data.pageNum];
+        if (page.errorback)
+          page.errorback(data.error)
+        else
+          throw data.error;
+      }, this);
+
       setTimeout(function pdfDocFontReadySetTimeout() {
         messageHandler.send('doc', this.data);
         this.workerReadyPromise.resolve(true);

src/worker.js

@@ -14,7 +14,6 @@ function MessageHandler(name, comObj) {
   ah['console_error'] = [function ahConsoleError(data) {
       console.error.apply(console, data);
   }];
-
   comObj.onmessage = function messageHandlerComObjOnMessage(event) {
     var data = event.data;
     if (data.action in ah) {
@@ -67,7 +66,6 @@ var WorkerMessageHandler = {
     handler.on('page_request', function wphSetupPageRequest(pageNum) {
       pageNum = parseInt(pageNum);
 
-      var page = pdfDoc.getPage(pageNum);
 
       // The following code does quite the same as
       // Page.prototype.startRendering, but stops at one point and sends the
@@ -77,9 +75,22 @@ var WorkerMessageHandler = {
       var start = Date.now();
 
       var dependency = [];
-
-      // Pre compile the pdf page and fetch the fonts/images.
-      var IRQueue = page.getIRQueue(handler, dependency);
+      try {
+        var page = pdfDoc.getPage(pageNum);
+        // Pre compile the pdf page and fetch the fonts/images.
+        var IRQueue = page.getIRQueue(handler, dependency);
+      } catch(e) {
+        // Turn the error into an obj that can be serialized
+        e = {
+          message: e.message,
+          stack: e.stack
+        };
+        handler.send('page_error', {
+          pageNum: pageNum,
+          error: e
+        });
+        return;
+      }
 
       console.log('page=%d - getIRQueue: time=%dms, len=%d', pageNum,
                                   Date.now() - start, IRQueue.fnArray.length);