Initial support for lazy root creation

14 files changed, 457 insertions, 126 deletions

diff --git a/WebContent/VAADIN/vaadinBootstrap.js b/WebContent/VAADIN/vaadinBootstrap.js
index 0aec37efe7..2178e2abe2 100644
--- a/WebContent/VAADIN/vaadinBootstrap.js
+++ b/WebContent/VAADIN/vaadinBootstrap.js
@@ -43,8 +43,6 @@
 		
 		var url = basePath + widgetset + "/" + widgetset + ".nocache.js?" + new Date().getTime();
 		
-		//document.write("<script type='text/javascript' src='"+url+"'></script>");
-		
 		var scriptTag = document.createElement('script');
 		scriptTag.setAttribute('type', 'text/javascript');
 		scriptTag.setAttribute('src', url);
@@ -58,7 +56,7 @@
 			if (defaults) {
 				throw "Defaults already defined";
 			}
-			log("Got defaults", defaults)
+			log("Got defaults", d)
 			defaults = d;
 		},
 		initApplication: function(appId, config) {
@@ -73,27 +71,45 @@
 				}
 				return value;
 			}
-
-			var themeUri = getConfig('themeUri');
-			if (themeUri) {
-				loadTheme(themeUri);
-			}
-			
-			var widgetsetBase = getConfig('widgetsetBase');
-			var widgetset = getConfig('widgetset');
-			if (widgetset && widgetsetBase) {
-				loadWidgetset(widgetsetBase, widgetset);
-				if (widgetsetApps[widgetset]) {
-					widgetsetApps[widgetset].push(appId);
-				}  else {
-					widgetsetApps[widgetset] = [appId];
-				}
-			}
 			
-			if (getConfig("debug")) {
-				// TODO debug state is now global for the entire page, but should somehow only be set for the current application  
-				window.vaadin.debug = true;
-			}
+			var fetchRootConfig = function() {
+				log('Fetching root config');
+				var url = getConfig('appUri');
+				// Root id
+				url += ((/\?/).test(url) ? "&" : "?") + "browserDetails";
+				url += '&rootId=' + getConfig('rootId');
+				// Uri fragment
+				url += '&f=' + encodeURIComponent(location.hash);
+				// Timestamp to avoid caching
+				url += '&' + (new Date()).getTime();
+				
+				var r = new XMLHttpRequest();
+				r.open('POST', url, true);
+				r.onreadystatechange = function (aEvt) {  
+					if (r.readyState == 4) {  
+						if (r.status == 200){
+							log(r.responseText);
+							// TODO Does this work in all supported browsers?
+							var updatedConfig = JSON.parse(r.responseText);
+							
+							// Copy new properties to the config object
+							for (var property in updatedConfig) {
+								if (updatedConfig.hasOwnProperty(property)) {
+									config[property] = updatedConfig[property];
+								}
+							}
+							
+							// Try bootstrapping again, this time without fetching missing info
+							bootstrapApp(false);
+						} else {
+							log('Error', r.statusText);  
+						}
+					}  
+				};
+				r.send(null);
+				
+				log('sending request to ', url);
+			};			
 			
 			//Export public data
 			var app = {
@@ -101,6 +117,34 @@
 			};
 			apps[appId] = app;
 			
+			var bootstrapApp = function(mayDefer) {
+				var themeUri = getConfig('themeUri');
+				if (themeUri) {
+					loadTheme(themeUri);
+				}
+				
+				var widgetsetBase = getConfig('widgetsetBase');
+				var widgetset = getConfig('widgetset');
+				if (widgetset && widgetsetBase) {
+					loadWidgetset(widgetsetBase, widgetset);
+					if (widgetsetApps[widgetset]) {
+						widgetsetApps[widgetset].push(appId);
+					}  else {
+						widgetsetApps[widgetset] = [appId];
+					}
+				} else if (mayDefer) {
+					fetchRootConfig();
+				} else {
+					throw "Widgetset not defined";
+				}
+			}
+			bootstrapApp(true);
+
+			if (getConfig("debug")) {
+				// TODO debug state is now global for the entire page, but should somehow only be set for the current application  
+				window.vaadin.debug = true;
+			}
+			
 			return app;
 		},
 		getApp: function(appId) {
diff --git a/src/com/vaadin/Application.java b/src/com/vaadin/Application.java
index c4a370b8d9..d284492c1c 100644
--- a/src/com/vaadin/Application.java
+++ b/src/com/vaadin/Application.java
@@ -29,6 +29,7 @@ import java.util.regex.Pattern;
 
 import com.vaadin.service.ApplicationContext;
 import com.vaadin.terminal.ApplicationResource;
+import com.vaadin.terminal.CombinedRequest;
 import com.vaadin.terminal.ErrorMessage;
 import com.vaadin.terminal.RequestHandler;
 import com.vaadin.terminal.SystemError;
@@ -36,6 +37,7 @@ import com.vaadin.terminal.Terminal;
 import com.vaadin.terminal.VariableOwner;
 import com.vaadin.terminal.WrappedRequest;
 import com.vaadin.terminal.WrappedResponse;
+import com.vaadin.terminal.gwt.client.ApplicationConnection;
 import com.vaadin.terminal.gwt.server.ChangeVariablesErrorEvent;
 import com.vaadin.terminal.gwt.server.WebApplicationContext;
 import com.vaadin.ui.AbstractComponent;
@@ -118,8 +120,6 @@ public class Application implements Terminal.ErrorListener, Serializable {
                         "mainWindow has already been set");
             }
             this.mainWindow = mainWindow;
-            registerRoot(mainWindow);
-            mainWindow.init(null);
         }
 
         public Root getMainWindow() {
@@ -171,8 +171,6 @@ public class Application implements Terminal.ErrorListener, Serializable {
 
         public void addWindow(Root root, String name) {
             legacyRootNames.put(name, root);
-            registerRoot(root);
-            root.init(null);
         }
 
         public void removeWindow(Root root) {
@@ -211,6 +209,24 @@ public class Application implements Terminal.ErrorListener, Serializable {
         }
     }
 
+    private static class PendingRootRequest {
+
+        private final Map<String, String[]> parameterMap;
+        private final String pathInfo;
+
+        public PendingRootRequest(WrappedRequest request) {
+            parameterMap = new HashMap<String, String[]>(
+                    request.getParameterMap());
+            pathInfo = request.getRequestPathInfo();
+        }
+
+        public CombinedRequest getCombinedRequest(
+                final WrappedRequest secondRequest) {
+            return new CombinedRequest(secondRequest,
+                    Collections.unmodifiableMap(parameterMap), pathInfo);
+        }
+    }
+
     private final static Logger logger = Logger.getLogger(Application.class
             .getName());
 
@@ -284,6 +300,12 @@ public class Application implements Terminal.ErrorListener, Serializable {
     private boolean productionMode = true;
 
     /**
+     * Keeps track of requests for which a root should be created once more
+     * information is available.
+     */
+    private Map<Integer, PendingRootRequest> pendingRoots = new HashMap<Integer, PendingRootRequest>();
+
+    /**
      * Gets the user of the application.
      * 
      * <p>
@@ -1570,27 +1592,8 @@ public class Application implements Terminal.ErrorListener, Serializable {
 
     }
 
-    public Root getRoot(WrappedRequest request) {
-        // TODO What if getRoot is called again for this request?
-
-        // TODO implement support for throwing exception if more
-        // information is required to create a root
-        Root root = createRoot(request);
-
-        registerRoot(root);
-
-        // TODO implement lazy init of root if indicated by annotation
-        root.init(request);
-
-        return root;
-    }
-
-    protected void registerRoot(Root root) {
-        root.registerRoot(this, nextRootId++);
-        roots.put(Integer.valueOf(root.getRootId()), root);
-    }
-
-    protected Root createRoot(WrappedRequest request) {
+    protected Root getRoot(WrappedRequest request)
+            throws RootRequiresMoreInformation {
         String rootClassName = getRootClassName(request);
         try {
             Class<? extends Root> rootClass = Class.forName(rootClassName)
@@ -1666,11 +1669,70 @@ public class Application implements Terminal.ErrorListener, Serializable {
         currentApplication.set(application);
     }
 
-    public Root getRootById(int rootId) {
-        return roots.get(Integer.valueOf(rootId));
-    }
-
     public boolean isProductionMode() {
         return productionMode;
     }
+
+    public int registerPendingRoot(WrappedRequest request) {
+        int rootId = nextRootId++;
+        pendingRoots.put(Integer.valueOf(rootId), new PendingRootRequest(
+                request));
+        return rootId;
+    }
+
+    public CombinedRequest getCombinedRequest(WrappedRequest request) {
+        PendingRootRequest pendingRootRequest = pendingRoots
+                .get(getRootId(request));
+        if (pendingRootRequest == null) {
+            return null;
+        } else {
+            return pendingRootRequest.getCombinedRequest(request);
+        }
+    }
+
+    public Root getRootForRequest(WrappedRequest request)
+            throws RootRequiresMoreInformation {
+        Root root = Root.getCurrentRoot();
+        if (root != null) {
+            return root;
+        }
+        Integer rootId = getRootId(request);
+
+        synchronized (this) {
+            PendingRootRequest pendingRootRequest = pendingRoots.remove(rootId);
+            if (pendingRootRequest == null && rootId != null) {
+                root = roots.get(rootId);
+            } else {
+                root = getRoot(request);
+                if (root.getApplication() == null) {
+                    root.setApplication(this);
+                }
+                if (root.getRootId() < 0) {
+                    int id = (rootId != null ? rootId.intValue() : nextRootId++);
+                    root.setRootId(id);
+                    roots.put(Integer.valueOf(root.getRootId()), root);
+
+                    // TODO implement lazy init of root if indicated by
+                    // annotation
+                    root.init(request);
+                }
+            }
+        }
+
+        Root.setCurrentRoot(root);
+        return root;
+    }
+
+    private Integer getRootId(WrappedRequest request) {
+        if (request instanceof CombinedRequest) {
+            // Combined requests has the rootid parameter in the second request
+            CombinedRequest combinedRequest = (CombinedRequest) request;
+            request = combinedRequest.getSecondRequest();
+        }
+        String rootIdString = request
+                .getParameter(ApplicationConnection.ROOT_ID_PARAMETER);
+        Integer rootId = rootIdString == null ? null
+                : new Integer(rootIdString);
+        return rootId;
+    }
 }
diff --git a/src/com/vaadin/RootRequiresMoreInformation.java b/src/com/vaadin/RootRequiresMoreInformation.java
new file mode 100644
index 0000000000..5fa86fa044
--- /dev/null
+++ b/src/com/vaadin/RootRequiresMoreInformation.java
@@ -0,0 +1,17 @@
+/*
+@ITMillApache2LicenseForJavaFiles@
+ */
+
+package com.vaadin;
+
+/**
+ * Exception that is thrown to indicate that creating or initializing the root
+ * requires information from the web browser (e.g. screen size or URI fragment)
+ * to be present.
+ * 
+ * This exception may not be thrown if that information is already present in
+ * the current WrappedRequest.
+ */
+public class RootRequiresMoreInformation extends Exception {
+    // Nothing of interest here
+}
diff --git a/src/com/vaadin/terminal/CombinedRequest.java b/src/com/vaadin/terminal/CombinedRequest.java
new file mode 100644
index 0000000000..98d0a491aa
--- /dev/null
+++ b/src/com/vaadin/terminal/CombinedRequest.java
@@ -0,0 +1,89 @@
+/*
+@ITMillApache2LicenseForJavaFiles@
+ */
+
+package com.vaadin.terminal;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Collections;
+import java.util.Map;
+
+public class CombinedRequest implements WrappedRequest {
+
+    private final WrappedRequest secondRequest;
+    private final Map<String, String[]> parameterMap;
+    private final String pathInfo;
+
+    public CombinedRequest(WrappedRequest secondRequest,
+            Map<String, String[]> parameterMap, String pathInfo) {
+        this.secondRequest = secondRequest;
+        this.parameterMap = parameterMap;
+        this.pathInfo = pathInfo;
+    }
+
+    public String getParameter(String parameter) {
+        String[] strings = parameterMap.get(parameter);
+        if (strings == null || strings.length == 0) {
+            return null;
+        } else {
+            return strings[0];
+        }
+    }
+
+    public Map<String, String[]> getParameterMap() {
+        return Collections.unmodifiableMap(parameterMap);
+    }
+
+    public int getContentLength() {
+        return secondRequest.getContentLength();
+    }
+
+    public InputStream getInputStream() throws IOException {
+        return secondRequest.getInputStream();
+    }
+
+    public Object getAttribute(String name) {
+        return secondRequest.getAttribute(name);
+    }
+
+    public void setAttribute(String name, Object value) {
+        secondRequest.setAttribute(name, value);
+    }
+
+    public String getRequestPathInfo() {
+        return pathInfo;
+    }
+
+    public int getSessionMaxInactiveInterval() {
+        return secondRequest.getSessionMaxInactiveInterval();
+    }
+
+    public Object getSessionAttribute(String name) {
+        return secondRequest.getSessionAttribute(name);
+    }
+
+    public void setSessionAttribute(String name, Object attribute) {
+        secondRequest.setSessionAttribute(name, attribute);
+    }
+
+    public String getContentType() {
+        return secondRequest.getContentType();
+    }
+
+    public String getStaticFileLocation() {
+        return secondRequest.getStaticFileLocation();
+    }
+
+    public BrowserDetails getBrowserDetails() {
+        return new BrowserDetails() {
+            public String getUriFragmet() {
+                return secondRequest.getParameter("f");
+            }
+        };
+    }
+
+    public WrappedRequest getSecondRequest() {
+        return secondRequest;
+    }
+}
diff --git a/src/com/vaadin/terminal/WrappedRequest.java b/src/com/vaadin/terminal/WrappedRequest.java
index 5ab11a7374..07a8721ea1 100644
--- a/src/com/vaadin/terminal/WrappedRequest.java
+++ b/src/com/vaadin/terminal/WrappedRequest.java
@@ -10,6 +10,10 @@ import java.io.Serializable;
 import java.util.Map;
 
 public interface WrappedRequest extends Serializable {
+    public interface BrowserDetails {
+        public String getUriFragmet();
+    }
+    
     /**
      * Get the named HTTP or portlet request parameter.
      * 
@@ -65,4 +69,6 @@ public interface WrappedRequest extends Serializable {
 
     public String getStaticFileLocation();
 
+    public BrowserDetails getBrowserDetails();
+
 }
diff --git a/src/com/vaadin/terminal/gwt/server/AbstractApplicationPortlet.java b/src/com/vaadin/terminal/gwt/server/AbstractApplicationPortlet.java
index 94c3e3e3e4..da912de753 100644
--- a/src/com/vaadin/terminal/gwt/server/AbstractApplicationPortlet.java
+++ b/src/com/vaadin/terminal/gwt/server/AbstractApplicationPortlet.java
@@ -447,8 +447,8 @@ public abstract class AbstractApplicationPortlet extends GenericPortlet
                             // root = application.getRoot();
                             break;
                         default:
-                            root = applicationManager.getApplicationRoot(
-                                    wrappedRequest, application);
+                            root = application
+                                    .getRootForRequest(wrappedRequest);
                         }
                         // if window not found, not a problem - use null
                     }
diff --git a/src/com/vaadin/terminal/gwt/server/AbstractApplicationServlet.java b/src/com/vaadin/terminal/gwt/server/AbstractApplicationServlet.java
index 401f1e2c68..951b9a85bb 100644
--- a/src/com/vaadin/terminal/gwt/server/AbstractApplicationServlet.java
+++ b/src/com/vaadin/terminal/gwt/server/AbstractApplicationServlet.java
@@ -452,14 +452,17 @@ public abstract class AbstractApplicationServlet extends HttpServlet implements
                 return;
             } else if (requestType == RequestType.UIDL) {
                 // Handles AJAX UIDL requests
-                Root root = applicationManager.getApplicationRoot(
-                        wrappedRequest, application);
+                Root root = application.getRootForRequest(wrappedRequest);
                 if (root == null) {
                     throw new ServletException(ERROR_NO_WINDOW_FOUND);
                 }
                 applicationManager.handleUidlRequest(wrappedRequest,
                         wrappedResponse, servletWrapper, root);
                 return;
+            } else if (requestType == RequestType.BROWSER_DETAILS) {
+                applicationManager.handleBrowserDetailsRequest(wrappedRequest,
+                        wrappedResponse, application);
+                return;
             }
 
             // Removes application if it has stopped (mayby by thread or
@@ -1228,12 +1231,14 @@ public abstract class AbstractApplicationServlet extends HttpServlet implements
     }
 
     protected enum RequestType {
-        FILE_UPLOAD, UIDL, OTHER, STATIC_FILE, APPLICATION_RESOURCE;
+        FILE_UPLOAD, BROWSER_DETAILS, UIDL, OTHER, STATIC_FILE, APPLICATION_RESOURCE;
     }
 
     protected RequestType getRequestType(HttpServletRequest request) {
         if (isFileUploadRequest(request)) {
             return RequestType.FILE_UPLOAD;
+        } else if (isBrowserDetailsRequest(request)) {
+            return RequestType.BROWSER_DETAILS;
         } else if (isUIDLRequest(request)) {
             return RequestType.UIDL;
         } else if (isStaticResourceRequest(request)) {
@@ -1247,6 +1252,11 @@ public abstract class AbstractApplicationServlet extends HttpServlet implements
 
     }
 
+    private static boolean isBrowserDetailsRequest(HttpServletRequest request) {
+        return "POST".equals(request.getMethod())
+                && request.getParameter("browserDetails") != null;
+    }
+
     private boolean isApplicationRequest(HttpServletRequest request) {
         String path = getRequestPathInfo(request);
         if (path != null && path.startsWith("/APP/")) {
diff --git a/src/com/vaadin/terminal/gwt/server/AbstractCommunicationManager.java b/src/com/vaadin/terminal/gwt/server/AbstractCommunicationManager.java
index d72015dae4..d047ac8170 100644
--- a/src/com/vaadin/terminal/gwt/server/AbstractCommunicationManager.java
+++ b/src/com/vaadin/terminal/gwt/server/AbstractCommunicationManager.java
@@ -43,6 +43,10 @@ import java.util.logging.Logger;
 
 import com.vaadin.Application;
 import com.vaadin.Application.SystemMessages;
+import com.vaadin.RootRequiresMoreInformation;
+import com.vaadin.external.json.JSONException;
+import com.vaadin.external.json.JSONObject;
+import com.vaadin.terminal.CombinedRequest;
 import com.vaadin.terminal.PaintException;
 import com.vaadin.terminal.PaintTarget;
 import com.vaadin.terminal.Paintable;
@@ -90,15 +94,18 @@ public abstract class AbstractCommunicationManager implements
             .getLogger(AbstractCommunicationManager.class.getName());
 
     private static final RequestHandler APP_RESOURCE_HANDLER = new ApplicationResourceHandler();
-    private static final RequestHandler AJAX_PAGE_HANDLER = new AjaxPageHandler() {
+    private static final AjaxPageHandler AJAX_PAGE_HANDLER = new AjaxPageHandler() {
 
         @Override
-        protected String getApplicationOrSystemProperty(
-                WrappedRequest request, String parameter,
-                String defaultValue) {
+        protected String getApplicationOrSystemProperty(WrappedRequest request,
+                String parameter, String defaultValue) {
+            if (request instanceof CombinedRequest) {
+                CombinedRequest combinedRequest = (CombinedRequest) request;
+                request = combinedRequest.getSecondRequest();
+            }
             WrappedHttpServletRequest r = (WrappedHttpServletRequest) request;
-            return r.getServlet().getApplicationOrSystemProperty(
-                    parameter, defaultValue);
+            return r.getServlet().getApplicationOrSystemProperty(parameter,
+                    defaultValue);
         }
 
     };
@@ -1629,32 +1636,6 @@ public abstract class AbstractCommunicationManager implements
     }
 
     /**
-     * Gets the existing application or creates a new one. Get a window within
-     * an application based on the requested URI.
-     * 
-     * @param request
-     *            the HTTP Request.
-     * @param application
-     *            the Application to query for window.
-     * @return Window matching the given URI or null if not found.
-     */
-    public Root getApplicationRoot(WrappedRequest request,
-            Application application) {
-        String rootIdString = request
-                .getParameter(ApplicationConnection.ROOT_ID_PARAMETER);
-        Root root = null;
-        synchronized (application) {
-            if (rootIdString != null) {
-                int rootId = Integer.parseInt(rootIdString);
-                root = application.getRootById(rootId);
-            }
-        }
-
-        Root.setCurrentRoot(root);
-        return root;
-    }
-
-    /**
      * Ends the Application.
      * 
      * The browser is redirected to the Application logout URL set with
@@ -1951,6 +1932,39 @@ public abstract class AbstractCommunicationManager implements
         return application.handleRequest(request, response);
     }
 
+    public void handleBrowserDetailsRequest(WrappedRequest request,
+            WrappedResponse response, Application application)
+            throws IOException {
+
+        // TODO Handle npe if id has not been registered
+        CombinedRequest combinedRequest = application
+                .getCombinedRequest(request);
+
+        try {
+            Root root = application.getRootForRequest(combinedRequest);
+
+            // Use the same logic as for determined roots
+            String widgetset = AJAX_PAGE_HANDLER.getWidgetsetForRoot(
+                    combinedRequest, root);
+            String theme = AJAX_PAGE_HANDLER.getThemeForRoot(combinedRequest,
+                    root);
+            String themeUri = AJAX_PAGE_HANDLER.getThemeUri(theme,
+                    combinedRequest);
+
+            JSONObject params = new JSONObject();
+            params.put("widgetset", widgetset);
+            params.put("themeUri", themeUri);
+            response.getWriter().write(params.toString());
+        } catch (RootRequiresMoreInformation e) {
+            // Requiring more information at this point is not allowed
+            // TODO handle in a better way
+            throw new RuntimeException(e);
+        } catch (JSONException e) {
+            // TODO Auto-generated catch block
+            e.printStackTrace();
+        }
+    }
+
     /**
      * Stream that extracts content from another stream until the boundary
      * string is encountered.
diff --git a/src/com/vaadin/terminal/gwt/server/AjaxPageHandler.java b/src/com/vaadin/terminal/gwt/server/AjaxPageHandler.java
index 3979ab4ff2..0ae7d8d884 100644
--- a/src/com/vaadin/terminal/gwt/server/AjaxPageHandler.java
+++ b/src/com/vaadin/terminal/gwt/server/AjaxPageHandler.java
@@ -7,6 +7,7 @@ import java.io.OutputStreamWriter;
 import javax.servlet.http.HttpServletResponse;
 
 import com.vaadin.Application;
+import com.vaadin.RootRequiresMoreInformation;
 import com.vaadin.external.json.JSONException;
 import com.vaadin.external.json.JSONObject;
 import com.vaadin.terminal.RequestHandler;
@@ -22,15 +23,21 @@ public abstract class AjaxPageHandler implements RequestHandler {
             throws IOException {
 
         // TODO Should all urls be handled here?
-        Root root = application.getRoot(request);
-
-        if (root == null) {
-            writeError(response, new Throwable("No Root found"));
-            return true;
+        int rootId;
+        try {
+            Root root = application.getRootForRequest(request);
+            if (root == null) {
+                writeError(response, new Throwable("No Root found"));
+                return true;
+            }
+
+            rootId = root.getRootId();
+        } catch (RootRequiresMoreInformation e) {
+            rootId = application.registerPendingRoot(request);
         }
 
         try {
-            writeAjaxPage(request, response, root);
+            writeAjaxPage(request, response, application, rootId);
         } catch (JSONException e) {
             writeError(response, e);
         }
@@ -39,13 +46,14 @@ public abstract class AjaxPageHandler implements RequestHandler {
     }
 
     protected final void writeAjaxPage(WrappedRequest request,
-            WrappedResponse response, Root root) throws IOException,
-            JSONException {
-        Application application = root.getApplication();
+            WrappedResponse response, Application application, int rootId)
+            throws IOException, JSONException {
         final BufferedWriter page = new BufferedWriter(new OutputStreamWriter(
                 response.getOutputStream(), "UTF-8"));
 
-        String title = ((root.getCaption() == null) ? "Vaadin "
+        Root root = Root.getCurrentRoot();
+
+        String title = ((root == null || root.getCaption() == null) ? "Vaadin "
                 + AbstractApplicationServlet.VERSION_MAJOR : root.getCaption());
 
         /* Fetch relative url to application */
@@ -78,9 +86,11 @@ public abstract class AjaxPageHandler implements RequestHandler {
         }
         appId = appId + "-" + hashCode;
 
+        String widgetset = getWidgetsetForRoot(request, root);
+
         // TODO include initial UIDL in the scripts?
-        writeAjaxPageHtmlVaadinScripts(themeName, page, appUrl, themeUri,
-                appId, request, root);
+        writeAjaxPageHtmlVaadinScripts(page, appUrl, themeUri, appId, request,
+                application, rootId, widgetset);
 
         /*- Add classnames;
          *      .v-app
@@ -109,6 +119,23 @@ public abstract class AjaxPageHandler implements RequestHandler {
         page.close();
     }
 
+    public String getWidgetsetForRoot(WrappedRequest request, Root root) {
+        if (root == null) {
+            // Defer widgetset selection
+            return null;
+        }
+
+        String widgetset = root.getApplication().getWidgetsetForRoot(root);
+        if (widgetset == null) {
+            widgetset = getApplicationOrSystemProperty(request,
+                    AbstractApplicationServlet.PARAMETER_WIDGETSET,
+                    AbstractApplicationServlet.DEFAULT_WIDGETSET);
+        }
+
+        widgetset = AbstractApplicationServlet.stripSpecialChars(widgetset);
+        return widgetset;
+    }
+
     /**
      * Method to write the div element into which that actual Vaadin application
      * is rendered.
@@ -178,22 +205,20 @@ public abstract class AjaxPageHandler implements RequestHandler {
      * <p>
      * Override this method if you want to add some custom html around scripts.
      * 
-     * @param themeName
      * @param page
      * @param appUrl
      * @param themeUri
      * @param appId
      * @param request
+     * @param application
      * @param rootId
      * @throws IOException
      * @throws JSONException
      */
-    protected void writeAjaxPageHtmlVaadinScripts(String themeName,
-            final BufferedWriter page, String appUrl, String themeUri,
-            String appId, WrappedRequest request, Root root)
-            throws IOException, JSONException {
-
-        Application application = root.getApplication();
+    protected void writeAjaxPageHtmlVaadinScripts(final BufferedWriter page,
+            String appUrl, String themeUri, String appId,
+            WrappedRequest request, Application application, int rootId,
+            String widgetset) throws IOException, JSONException {
 
         String staticFileLocation = request.getStaticFileLocation();
 
@@ -225,8 +250,7 @@ public abstract class AjaxPageHandler implements RequestHandler {
 
         defaults.put("appUri", appUrl);
 
-        appConfig
-                .put(ApplicationConnection.ROOT_ID_PARAMETER, root.getRootId());
+        appConfig.put(ApplicationConnection.ROOT_ID_PARAMETER, rootId);
 
         if (isStandalone()) {
             defaults.put("standalone", true);
@@ -262,12 +286,6 @@ public abstract class AjaxPageHandler implements RequestHandler {
 
         defaults.put("widgetsetBase", widgetsetBase);
 
-        String widgetset = application.getWidgetsetForRoot(root);
-        widgetset = getApplicationOrSystemProperty(request,
-                AbstractApplicationServlet.PARAMETER_WIDGETSET,
-                AbstractApplicationServlet.DEFAULT_WIDGETSET);
-
-        widgetset = AbstractApplicationServlet.stripSpecialChars(widgetset);
         appConfig.put("widgetset", widgetset);
 
         page.write("vaadin.setDefaults(");
@@ -327,10 +345,12 @@ public abstract class AjaxPageHandler implements RequestHandler {
                 + "html, body {height:100%;margin:0;}</style>");
 
         // Add favicon links
-        page.write("<link rel=\"shortcut icon\" type=\"image/vnd.microsoft.icon\" href=\""
-                + themeUri + "/favicon.ico\" />");
-        page.write("<link rel=\"icon\" type=\"image/vnd.microsoft.icon\" href=\""
-                + themeUri + "/favicon.ico\" />");
+        if (themeUri != null) {
+            page.write("<link rel=\"shortcut icon\" type=\"image/vnd.microsoft.icon\" href=\""
+                    + themeUri + "/favicon.ico\" />");
+            page.write("<link rel=\"icon\" type=\"image/vnd.microsoft.icon\" href=\""
+                    + themeUri + "/favicon.ico\" />");
+        }
 
         page.write("<title>"
                 + AbstractApplicationServlet.safeEscapeForHtml(title)
@@ -387,7 +407,10 @@ public abstract class AjaxPageHandler implements RequestHandler {
      * @param request
      * @return
      */
-    private String getThemeUri(String themeName, WrappedRequest request) {
+    public String getThemeUri(String themeName, WrappedRequest request) {
+        if (themeName == null) {
+            return null;
+        }
         final String staticFilePath = request.getStaticFileLocation();
         return staticFilePath + "/"
                 + AbstractApplicationServlet.THEME_DIRECTORY_PATH + themeName;
@@ -400,7 +423,10 @@ public abstract class AjaxPageHandler implements RequestHandler {
      * @param root
      * @return
      */
-    private String getThemeForRoot(WrappedRequest request, Root root) {
+    public String getThemeForRoot(WrappedRequest request, Root root) {
+        if (root == null) {
+            return null;
+        }
         // Finds theme name
         String themeName;
 
diff --git a/src/com/vaadin/terminal/gwt/server/WrappedHttpServletRequest.java b/src/com/vaadin/terminal/gwt/server/WrappedHttpServletRequest.java
index 4d947d20b0..499243a74b 100644
--- a/src/com/vaadin/terminal/gwt/server/WrappedHttpServletRequest.java
+++ b/src/com/vaadin/terminal/gwt/server/WrappedHttpServletRequest.java
@@ -95,4 +95,9 @@ public class WrappedHttpServletRequest implements WrappedRequest {
     public String getStaticFileLocation() {
         return servlet.getStaticFilesLocation(request);
     }
+
+    public BrowserDetails getBrowserDetails() {
+        // No browserDetails available for normal requests
+        return null;
+    }
 }
\ No newline at end of file
diff --git a/src/com/vaadin/terminal/gwt/server/WrappedPortletRequest.java b/src/com/vaadin/terminal/gwt/server/WrappedPortletRequest.java
index e8e7350d42..7a671520dd 100644
--- a/src/com/vaadin/terminal/gwt/server/WrappedPortletRequest.java
+++ b/src/com/vaadin/terminal/gwt/server/WrappedPortletRequest.java
@@ -108,4 +108,9 @@ public class WrappedPortletRequest implements WrappedRequest {
         throw new UnsupportedOperationException("Please implement me!");
     }
 
+    public BrowserDetails getBrowserDetails() {
+        // No browserDetails available for normal requests
+        return null;
+    }
+
 }
\ No newline at end of file
diff --git a/src/com/vaadin/ui/Root.java b/src/com/vaadin/ui/Root.java
index d948d0ca9c..cb682609ef 100644
--- a/src/com/vaadin/ui/Root.java
+++ b/src/com/vaadin/ui/Root.java
@@ -85,7 +85,7 @@ public class Root extends AbstractComponentContainer implements
      */
     private Component scrollIntoView;
 
-    private int rootId;
+    private int rootId = -1;
 
     /**
      * Keeps track of the Actions added to this component, and manages the
@@ -225,17 +225,23 @@ public class Root extends AbstractComponentContainer implements
         return Collections.singleton((Component) getContent()).iterator();
     }
 
-    public void registerRoot(Application application, int rootId) {
+    public void setApplication(Application application) {
         if (application == null) {
             throw new NullPointerException("application");
         } else if (this.application != null) {
             throw new IllegalStateException("Application has already been set");
         } else {
             this.application = application;
-            this.rootId = rootId;
         }
     }
 
+    public void setRootId(int rootId) {
+        if (this.rootId != -1) {
+            throw new IllegalStateException("Root id has already been defined");
+        }
+        this.rootId = rootId;
+    }
+
     public int getRootId() {
         return rootId;
     }
diff --git a/tests/testbench/com/vaadin/tests/components/loginform/LoginFormWithMultipleWindows.java b/tests/testbench/com/vaadin/tests/components/loginform/LoginFormWithMultipleWindows.java
index ed6deb420b..ad87549e50 100644
--- a/tests/testbench/com/vaadin/tests/components/loginform/LoginFormWithMultipleWindows.java
+++ b/tests/testbench/com/vaadin/tests/components/loginform/LoginFormWithMultipleWindows.java
@@ -11,7 +11,7 @@ import com.vaadin.ui.Root;
 public class LoginFormWithMultipleWindows extends Application {
 
     @Override
-    protected Root createRoot(WrappedRequest request) {
+    protected Root getRoot(WrappedRequest request) {
         return new LoginFormWindow();
     }
 
diff --git a/tests/testbench/com/vaadin/tests/components/root/LazyInitRoots.java b/tests/testbench/com/vaadin/tests/components/root/LazyInitRoots.java
new file mode 100644
index 0000000000..96d9a465e2
--- /dev/null
+++ b/tests/testbench/com/vaadin/tests/components/root/LazyInitRoots.java
@@ -0,0 +1,47 @@
+package com.vaadin.tests.components.root;
+
+import com.vaadin.Application;
+import com.vaadin.RootRequiresMoreInformation;
+import com.vaadin.terminal.ExternalResource;
+import com.vaadin.terminal.WrappedRequest;
+import com.vaadin.terminal.WrappedRequest.BrowserDetails;
+import com.vaadin.ui.Label;
+import com.vaadin.ui.Link;
+import com.vaadin.ui.Root;
+import com.vaadin.ui.VerticalLayout;
+
+public class LazyInitRoots extends Application {
+
+    @Override
+    public Root getRoot(WrappedRequest request)
+            throws RootRequiresMoreInformation {
+        if (request.getParameter("lazyCreate") != null) {
+            BrowserDetails browserDetails = request.getBrowserDetails();
+            if (browserDetails == null) {
+                throw new RootRequiresMoreInformation();
+            } else {
+                VerticalLayout content = new VerticalLayout();
+                content.addComponent(new Label(browserDetails.getUriFragmet()));
+                return new Root(content);
+            }
+        } else {
+            VerticalLayout content = new VerticalLayout();
+            Link lazyCreateLink = new Link("Open lazyCreate root",
+                    new ExternalResource(getURL() + "?lazyCreate"));
+            lazyCreateLink.setTargetName("_blank");
+            content.addComponent(lazyCreateLink);
+            return new Root(content);
+        }
+    }
+
+    protected String getDescription() {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+    protected Integer getTicketNumber() {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
+}