             return self.loadFileURL(url, allowingReadAccessTo: baseURL) != nil
         }
         else
-        if k.about == url.scheme {
-            return appDelegate.openURLInNewWindow(url, attachTo: window)
+        if k.helium == url.scheme {
+            let paths = url.pathComponents
+            guard "/" == paths.first, paths.count == 3 else { return false }
+            let type = paths[1]
+
+            switch type {// type data,html,text
+
+            case k.html,k.text:
+                return self.loadHTMLString(doc.contents! as! String, baseURL: nil) != nil
+                
+            case k.data:
+                ///return self.load(doc.contents as! Data, mimeType: <#T##String#>, characterEncodingName: UTF8, baseURL: <#T##URL#>) != nil
+                break
+                
+            default:
+                Swift.print("unknown helium: type \(type)")
+                return false
+            }
         }
         else
         if self.load(URLRequest(url: url)) != nil {
-            if let doc = self.webViewController?.document {
-                doc.fileURL = url
-                doc.save(doc)
-            }
+            doc.fileURL = url
+            doc.save(doc)
             return true
         }
         return false

        print("WK Scroll View \(String(describing: note.object)) will be opened now")
        if let scrollView : NSScrollView = note.object as? NSScrollView {
            scrollView.autohidesScrollers = true
        }*/
            
        if let document = heliumPanelController?.document, let url = document.fileURL, url != nil {
            _ = loadURL(url: url!)
        }
        else
        {
            clear()
        }
        
        //  load developer panel if asked - initially no
        self.webView.configuration.preferences.setValue(UserSettings.DeveloperExtrasEnabled.value, forKey: "developerExtrasEnabled")
    }
    
    override func viewWillAppear() {
        super.viewWillAppear()
        
        guard let doc = self.document, let url = doc.fileURL else { return }
        
        switch doc.docGroup {
        case .playlist:
            break
            
        default:
            if url.isFileURL {
                if [k.hpi].contains(url.pathExtension) {
                    webView.load(URLRequest.init(url: url))
                }
                else
                {
                    if appDelegate.isSandboxed() != appDelegate.storeBookmark(url: url) {
                        Swift.print("Yoink, unable to sandbox \(url)")
                    }
                    let baseURL = appDelegate.authenticateBaseURL(url)
                        
                    webView.loadFileURL(url, allowingReadAccessTo: baseURL)
                }
            }
            else
            if k.about == url.scheme {
                webView.loadHTMLString(webView.htmlContents!, baseURL: nil)
            }
            else
            {
                webView.load(URLRequest.init(url: url))
            }
        }
    }
    

            let notif = Notification(name: Notification.Name(rawValue: "HeliumNewURL"), object: url, userInfo: [k.fini : true])
            NotificationCenter.default.post(notif)
        }
    }
    
    func webView(_ webView: WKWebView, didFinishLoad navigation: WKNavigation) {
