Introduce vaadinBootstrap.js and use it to init the widgetset

5 files changed, 335 insertions, 246 deletions

diff --git a/WebContent/VAADIN/vaadinBootstrap.js b/WebContent/VAADIN/vaadinBootstrap.js
new file mode 100644
index 0000000000..917aa2aa4a
--- /dev/null
+++ b/WebContent/VAADIN/vaadinBootstrap.js
@@ -0,0 +1,115 @@
+(function() {
+	var defaults;
+	var apps = {};
+	var themesLoaded = {};
+	var widgetsetsRequested = {}
+	var widgetsetApps = {};
+	
+	
+	var log = function() {
+		if (console && console.log) {
+			console.log(arguments);
+		}
+	}
+	
+	var loadTheme = function(url) {
+		log("loadTheme", url);
+		if(!themesLoaded[url]) {
+			var stylesheet = document.createElement('link');
+			stylesheet.setAttribute('rel', 'stylesheet');
+			stylesheet.setAttribute('type', 'text/css');
+			stylesheet.setAttribute('href', url + "/styles.css");
+			document.getElementsByTagName('head')[0].appendChild(stylesheet);
+			themesLoaded[url] = true;
+		}		
+	}
+	
+	var isWidgetsetLoaded = function(widgetset) {
+		var className = widgetset.replace(/\./g, "_");
+		return (typeof window[className]) != "undefined";
+	}
+	
+	var loadWidgetset = function(basePath, widgetset) {
+		if (widgetsetsRequested[widgetset]) {
+			//TODO Tell the widgetset to load another application
+			return;
+		}
+		log("load widgetset", basePath, widgetset)
+		setTimeout(function() {
+			if (!isWidgetsetLoaded(widgetset)) {
+				alert("Failed to load the widgetset: " + url);
+			}
+		}, 15000);
+		
+		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);
+		document.getElementsByTagName('head')[0].appendChild(scriptTag);
+		
+		widgetsetsRequested[widgetset] = true;
+	}
+	
+	window.vaadin = window.vaadin || {
+		setDefaults: function(d) {
+			if (defaults) {
+				throw "Defaults already defined";
+			}
+			log("Got defaults", defaults)
+			defaults = d;
+		},
+		initApplication: function(appId, config) {
+			if (apps[appId]) {
+				throw "Application " + appId + " already initialized";
+			}
+			log("init application", appId, config);
+			var getConfig = function(name) {
+				var value = config[name];
+				if (value === undefined) {
+					value = defaults[name];
+				}
+				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];
+				}
+			}
+			
+			//Export public data
+			var app = {
+				'getConfig': getConfig
+			};
+			apps[appId] = app;
+			
+			return app;
+		},
+		getApp: function(appId) {
+			var app = apps[appId]; 
+			return app;
+		},
+		popWidgetsetApp: function(widgetset) {
+			if (widgetsetApps[widgetset]) {
+				return widgetsetApps[widgetset].pop();
+			} else {
+				return null;
+			}
+		}
+	};
+	
+	log('Vaadin bootstrap loaded');
+})();
\ No newline at end of file
diff --git a/src/com/vaadin/terminal/gwt/DefaultWidgetSet.gwt.xml b/src/com/vaadin/terminal/gwt/DefaultWidgetSet.gwt.xml
index bdbcc75222..9cf2a828db 100644
--- a/src/com/vaadin/terminal/gwt/DefaultWidgetSet.gwt.xml
+++ b/src/com/vaadin/terminal/gwt/DefaultWidgetSet.gwt.xml
@@ -69,6 +69,9 @@
 	</replace-with>
 
 	<entry-point class="com.vaadin.terminal.gwt.client.ApplicationConfiguration" />
+	
+	<!-- Use the new cross site linker to get a nocache.js without document.write -->
+	<add-linker name="xsiframe" />	
 
 
 </module>
diff --git a/src/com/vaadin/terminal/gwt/client/ApplicationConfiguration.java b/src/com/vaadin/terminal/gwt/client/ApplicationConfiguration.java
index a9750e3626..854deb6e84 100644
--- a/src/com/vaadin/terminal/gwt/client/ApplicationConfiguration.java
+++ b/src/com/vaadin/terminal/gwt/client/ApplicationConfiguration.java
@@ -5,7 +5,6 @@ package com.vaadin.terminal.gwt.client;
 
 import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 
@@ -20,6 +19,84 @@ import com.vaadin.terminal.gwt.client.ui.VUnknownComponent;
 
 public class ApplicationConfiguration implements EntryPoint {
 
+    private static class JsoConfiguration extends JavaScriptObject {
+        protected JsoConfiguration() {
+            // JSO Constructor
+        }
+
+        private native String getConfigString(String name)
+        /*-{
+            var value = this.getConfig(name);
+            if (!value) {
+                return null;
+            } else {
+                return value +"";
+            } 
+        }-*/;
+
+        private native Boolean getConfigBoolean(String name)
+        /*-{
+            var value = this.getConfig(name);
+            if (value === null || value === undefined) {
+                return null;
+            } else {
+                return @java.lang.Boolean::valueOf(Z)(value);
+            } 
+        }-*/;
+
+        private native Integer getConfigInteger(String name)
+        /*-{
+            var value = this.getConfig(name);
+            if (value === null || value === undefined) {
+                return null;
+            } else {
+                return @java.lang.Integer::valueOf(I)(value);
+            } 
+        }-*/;
+
+        private native ErrorMessage getConfigError(String name)
+        /*-{
+            return this.getConfig(name);
+        }-*/;
+
+        private native JavaScriptObject getVersionInfoJSObject()
+        /*-{
+            return this.getConfig("versionInfo");
+        }-*/;
+
+        private native String getVaadinVersion()
+        /*-{
+            return this.getConfig("versionInfo").vaadinVersion;
+        }-*/;
+
+        private native String getApplicationVersion()
+        /*-{
+            return this.getConfig("versionInfo").applicationVersion;
+        }-*/;
+    }
+
+    public static final class ErrorMessage extends JavaScriptObject {
+
+        protected ErrorMessage() {
+            // JSO constructor
+        }
+
+        public final native String getCaption()
+        /*-{
+            return this.caption;
+        }-*/;
+
+        public final native String getMessage()
+        /*-{
+            return this.message;
+        }-*/;
+
+        public final native String getUrl()
+        /*-{
+            return this.url;
+        }-*/;
+    }
+
     /**
      * Builds number. For example 0-custom_tag in 5.0.0-custom_tag.
      */
@@ -39,16 +116,10 @@ public class ApplicationConfiguration implements EntryPoint {
     private String id;
     private String themeUri;
     private String appUri;
-    private JavaScriptObject versionInfo;
     private int rootId;
     private boolean standalone;
-    private String communicationErrorCaption;
-    private String communicationErrorMessage;
-    private String communicationErrorUrl;
-    private String authorizationErrorCaption;
-    private String authorizationErrorMessage;
-    private String authorizationErrorUrl;
-    private String requiredWidgetset;
+    private ErrorMessage communicationError;
+    private ErrorMessage authorizationError;
     private boolean useDebugIdInDom = true;
     private boolean usePortletURLs = false;
     private String portletUidlURLBase;
@@ -64,7 +135,6 @@ public class ApplicationConfiguration implements EntryPoint {
 
     private static int widgetsLoading;
 
-    private static ArrayList<ApplicationConnection> unstartedApplications = new ArrayList<ApplicationConnection>();
     private static ArrayList<ApplicationConnection> runningApplications = new ArrayList<ApplicationConnection>();
 
     public boolean usePortletURLs() {
@@ -110,131 +180,41 @@ public class ApplicationConfiguration implements EntryPoint {
     }
 
     public JavaScriptObject getVersionInfoJSObject() {
-        return versionInfo;
+        return getJsoConfiguration(id).getVersionInfoJSObject();
     }
 
-    public String getCommunicationErrorCaption() {
-        return communicationErrorCaption;
+    public ErrorMessage getCommunicationError() {
+        return communicationError;
     }
 
-    public String getCommunicationErrorMessage() {
-        return communicationErrorMessage;
+    public ErrorMessage getAuthorizationError() {
+        return authorizationError;
     }
 
-    public String getCommunicationErrorUrl() {
-        return communicationErrorUrl;
-    }
-
-    public String getAuthorizationErrorCaption() {
-        return authorizationErrorCaption;
-    }
-
-    public String getAuthorizationErrorMessage() {
-        return authorizationErrorMessage;
-    }
-
-    public String getAuthorizationErrorUrl() {
-        return authorizationErrorUrl;
-    }
-
-    public String getRequiredWidgetset() {
-        return requiredWidgetset;
-    }
-
-    private native void loadFromDOM()
-    /*-{
-
-        var id = this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::id;
-        if($wnd.vaadin.vaadinConfigurations && $wnd.vaadin.vaadinConfigurations[id]) {
-            var jsobj = $wnd.vaadin.vaadinConfigurations[id];
-            var uri = jsobj.appUri;
-            if(uri != null && uri[uri.length -1] != "/") {
-                uri = uri + "/";
-            }
-            this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::appUri = uri;
-            this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::themeUri = jsobj.themeUri;
-            if(jsobj.rootId) {
-                this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::rootId = jsobj.rootId;
-            }
-            if('useDebugIdInDom' in jsobj && typeof(jsobj.useDebugIdInDom) == "boolean") {
-                this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::useDebugIdInDom = jsobj.useDebugIdInDom;
-            }
-            if(jsobj.versionInfo) {
-                this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::versionInfo = jsobj.versionInfo;
-            }
-            if(jsobj.comErrMsg) {
-                this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::communicationErrorCaption = jsobj.comErrMsg.caption;
-                this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::communicationErrorMessage = jsobj.comErrMsg.message;
-                this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::communicationErrorUrl = jsobj.comErrMsg.url;
-            }
-            if(jsobj.authErrMsg) {
-                this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::authorizationErrorCaption = jsobj.authErrMsg.caption;
-                this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::authorizationErrorMessage = jsobj.authErrMsg.message;
-                this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::authorizationErrorUrl = jsobj.authErrMsg.url;
-            }
-            if (jsobj.usePortletURLs) {
-                this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::usePortletURLs = jsobj.usePortletURLs;
-            }
-            if (jsobj.portletUidlURLBase) {
-                this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::portletUidlURLBase = jsobj.portletUidlURLBase;
-            }
-            if (jsobj.standalone) {
-                this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::standalone = true;
-            }
-            if (jsobj.widgetset) {
-                this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::requiredWidgetset = jsobj.widgetset;
-            }
-        } else {
-            $wnd.alert("Vaadin app failed to initialize: " + this.id);
+    private void loadFromDOM() {
+        JsoConfiguration jsoConfiguration = getJsoConfiguration(id);
+        appUri = jsoConfiguration.getConfigString("appUri");
+        if (appUri != null && !appUri.endsWith("/")) {
+            appUri += '/';
         }
+        themeUri = jsoConfiguration.getConfigString("themeUri");
+        rootId = jsoConfiguration.getConfigInteger("rootId").intValue();
 
-     }-*/;
+        // null -> true
+        useDebugIdInDom = jsoConfiguration.getConfigBoolean("useDebugIdInDom") != Boolean.FALSE;
 
-    /**
-     * Inits the ApplicationConfiguration by reading the DOM and instantiating
-     * ApplicationConnections accordingly. Call {@link #startNextApplication()}
-     * to actually start the applications.
-     * 
-     * @param widgetset
-     *            the widgetset that is running the apps
-     */
-    public static void initConfigurations() {
-
-        ArrayList<String> appIds = new ArrayList<String>();
-        loadAppIdListFromDOM(appIds);
-
-        for (Iterator<String> it = appIds.iterator(); it.hasNext();) {
-            String appId = it.next();
-            ApplicationConfiguration appConf = getConfigFromDOM(appId);
-            if (canStartApplication(appConf)) {
-                ApplicationConnection a = GWT
-                        .create(ApplicationConnection.class);
-                a.init(widgetSet, appConf);
-                unstartedApplications.add(a);
-                consumeApplication(appId);
-            } else {
-                VConsole.log("Application "
-                        + appId
-                        + " was not started. Provided widgetset did not match with this module.");
-            }
-        }
+        // null -> false
+        usePortletURLs = jsoConfiguration.getConfigBoolean("usePortletURLs") == Boolean.TRUE;
 
-    }
+        portletUidlURLBase = jsoConfiguration
+                .getConfigString("portletUidlURLBase");
 
-    /**
-     * Marks an applicatin with given id to be initialized. Suggesting other
-     * modules should not try to start this application anymore.
-     * 
-     * @param appId
-     */
-    private native static void consumeApplication(String appId)
-    /*-{
-         $wnd.vaadin.vaadinConfigurations[appId].initialized = true;
-    }-*/;
+        // null -> false
+        standalone = jsoConfiguration.getConfigBoolean("standalone") == Boolean.TRUE;
+
+        communicationError = jsoConfiguration.getConfigError("comErrMsg");
+        authorizationError = jsoConfiguration.getConfigError("authErrMsg");
 
-    private static boolean canStartApplication(ApplicationConfiguration appConf) {
-        return appConf.getRequiredWidgetset() == null
-                || appConf.getRequiredWidgetset().equals(GWT.getModuleName());
     }
 
     /**
@@ -246,8 +226,12 @@ public class ApplicationConfiguration implements EntryPoint {
      * @return true if an unstarted application was found
      */
     public static boolean startNextApplication() {
-        if (unstartedApplications.size() > 0) {
-            ApplicationConnection a = unstartedApplications.remove(0);
+        String applicationId = getNextUnstartedApplicationId(GWT
+                .getModuleName());
+        if (applicationId != null) {
+            ApplicationConfiguration appConf = getConfigFromDOM(applicationId);
+            ApplicationConnection a = GWT.create(ApplicationConnection.class);
+            a.init(widgetSet, appConf);
             a.start();
             runningApplications.add(a);
             return true;
@@ -261,14 +245,15 @@ public class ApplicationConfiguration implements EntryPoint {
         return runningApplications;
     }
 
-    private native static void loadAppIdListFromDOM(ArrayList<String> list)
+    private native static String getNextUnstartedApplicationId(
+            String widgetsetName)
+    /*-{
+        return $wnd.vaadin.popWidgetsetApp(widgetsetName);
+     }-*/;
+
+    private native static JsoConfiguration getJsoConfiguration(String appId)
     /*-{
-         var j;
-         for(j in $wnd.vaadin.vaadinConfigurations) {
-             if(!$wnd.vaadin.vaadinConfigurations[j].initialized) {
-                 list.@java.util.Collection::add(Ljava/lang/Object;)(j);
-             }
-         }
+        return $wnd.vaadin.getApp(appId);
      }-*/;
 
     public static ApplicationConfiguration getConfigFromDOM(String appId) {
@@ -278,15 +263,13 @@ public class ApplicationConfiguration implements EntryPoint {
         return conf;
     }
 
-    public native String getServletVersion()
-    /*-{
-        return this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::versionInfo.vaadinVersion;
-    }-*/;
+    public String getServletVersion() {
+        return getJsoConfiguration(id).getVaadinVersion();
+    }
 
-    public native String getApplicationVersion()
-    /*-{
-        return this.@com.vaadin.terminal.gwt.client.ApplicationConfiguration::versionInfo.applicationVersion;
-    }-*/;
+    public String getApplicationVersion() {
+        return getJsoConfiguration(id).getApplicationVersion();
+    }
 
     public boolean useDebugIdInDOM() {
         return useDebugIdInDom;
@@ -464,7 +447,6 @@ public class ApplicationConfiguration implements EntryPoint {
             }
         });
 
-        initConfigurations();
         startNextApplication();
     }
 
diff --git a/src/com/vaadin/terminal/gwt/client/ApplicationConnection.java b/src/com/vaadin/terminal/gwt/client/ApplicationConnection.java
index 88f562bb92..8f745bba80 100644
--- a/src/com/vaadin/terminal/gwt/client/ApplicationConnection.java
+++ b/src/com/vaadin/terminal/gwt/client/ApplicationConnection.java
@@ -33,6 +33,7 @@ import com.google.gwt.user.client.ui.FocusWidget;
 import com.google.gwt.user.client.ui.Focusable;
 import com.google.gwt.user.client.ui.HasWidgets;
 import com.google.gwt.user.client.ui.Widget;
+import com.vaadin.terminal.gwt.client.ApplicationConfiguration.ErrorMessage;
 import com.vaadin.terminal.gwt.client.RenderInformation.FloatSize;
 import com.vaadin.terminal.gwt.client.RenderInformation.Size;
 import com.vaadin.terminal.gwt.client.ui.Field;
@@ -617,9 +618,9 @@ public class ApplicationConnection {
      */
     protected void showCommunicationError(String details) {
         VConsole.error("Communication error: " + details);
-        showError(details, configuration.getCommunicationErrorCaption(),
-                configuration.getCommunicationErrorMessage(),
-                configuration.getCommunicationErrorUrl());
+        ErrorMessage communicationError = configuration.getCommunicationError();
+        showError(details, communicationError.getCaption(),
+                communicationError.getMessage(), communicationError.getUrl());
     }
 
     /**
@@ -630,9 +631,9 @@ public class ApplicationConnection {
      */
     protected void showAuthenticationError(String details) {
         VConsole.error("Authentication error: " + details);
-        showError(details, configuration.getAuthorizationErrorCaption(),
-                configuration.getAuthorizationErrorMessage(),
-                configuration.getAuthorizationErrorUrl());
+        ErrorMessage authorizationError = configuration.getAuthorizationError();
+        showError(details, authorizationError.getCaption(),
+                authorizationError.getMessage(), authorizationError.getUrl());
     }
 
     /**
diff --git a/src/com/vaadin/terminal/gwt/server/AjaxPageHandler.java b/src/com/vaadin/terminal/gwt/server/AjaxPageHandler.java
index 75ca37f6eb..3979ab4ff2 100644
--- a/src/com/vaadin/terminal/gwt/server/AjaxPageHandler.java
+++ b/src/com/vaadin/terminal/gwt/server/AjaxPageHandler.java
@@ -4,9 +4,11 @@ import java.io.BufferedWriter;
 import java.io.IOException;
 import java.io.OutputStreamWriter;
 
-import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletResponse;
 
 import com.vaadin.Application;
+import com.vaadin.external.json.JSONException;
+import com.vaadin.external.json.JSONObject;
 import com.vaadin.terminal.RequestHandler;
 import com.vaadin.terminal.WrappedRequest;
 import com.vaadin.terminal.WrappedResponse;
@@ -23,17 +25,22 @@ public abstract class AjaxPageHandler implements RequestHandler {
         Root root = application.getRoot(request);
 
         if (root == null) {
-            writeError(response, null);
+            writeError(response, new Throwable("No Root found"));
             return true;
         }
 
-        writeAjaxPage(request, response, root);
+        try {
+            writeAjaxPage(request, response, root);
+        } catch (JSONException e) {
+            writeError(response, e);
+        }
 
         return true;
     }
 
     protected final void writeAjaxPage(WrappedRequest request,
-            WrappedResponse response, Root root) throws IOException {
+            WrappedResponse response, Root root) throws IOException,
+            JSONException {
         Application application = root.getApplication();
         final BufferedWriter page = new BufferedWriter(new OutputStreamWriter(
                 response.getOutputStream(), "UTF-8"));
@@ -71,6 +78,7 @@ public abstract class AjaxPageHandler implements RequestHandler {
         }
         appId = appId + "-" + hashCode;
 
+        // TODO include initial UIDL in the scripts?
         writeAjaxPageHtmlVaadinScripts(themeName, page, appUrl, themeUri,
                 appId, request, root);
 
@@ -177,129 +185,109 @@ public abstract class AjaxPageHandler implements RequestHandler {
      * @param appId
      * @param request
      * @param rootId
-     * @throws ServletException
      * @throws IOException
+     * @throws JSONException
      */
     protected void writeAjaxPageHtmlVaadinScripts(String themeName,
             final BufferedWriter page, String appUrl, String themeUri,
-            String appId, WrappedRequest request, Root root) throws IOException {
+            String appId, WrappedRequest request, Root root)
+            throws IOException, JSONException {
 
         Application application = root.getApplication();
 
-        String widgetset = application.getWidgetsetForRoot(root);
-        if (widgetset == null) {
-            widgetset = getApplicationOrSystemProperty(request,
-                    AbstractApplicationServlet.PARAMETER_WIDGETSET,
-                    AbstractApplicationServlet.DEFAULT_WIDGETSET);
-        }
-        String widgetsetBasePath = request.getStaticFileLocation();
-
-        widgetset = AbstractApplicationServlet.stripSpecialChars(widgetset);
+        String staticFileLocation = request.getStaticFileLocation();
 
-        final String widgetsetFilePath = widgetsetBasePath + "/"
-                + AbstractApplicationServlet.WIDGETSET_DIRECTORY_PATH
-                + widgetset + "/" + widgetset + ".nocache.js?"
-                + System.currentTimeMillis();
+        String widgetsetBase = staticFileLocation + "/"
+                + AbstractApplicationServlet.WIDGETSET_DIRECTORY_PATH;
 
         // Get system messages
         Application.SystemMessages systemMessages = AbstractApplicationServlet
                 .getSystemMessages(application.getClass());
 
+        page.write("<script type=\"text/javascript\" src=\"");
+        page.write(staticFileLocation);
+        page.write("/VAADIN/vaadinBootstrap.js\"></script>\n");
+
         page.write("<script type=\"text/javascript\">\n");
         page.write("//<![CDATA[\n");
-        page.write("if(!vaadin || !vaadin.vaadinConfigurations) {\n "
-                + "if(!vaadin) { var vaadin = {}} \n"
-                + "vaadin.vaadinConfigurations = {};\n"
-                + "if (!vaadin.themesLoaded) { vaadin.themesLoaded = {}; }\n");
-        if (!application.isProductionMode()) {
-            page.write("vaadin.debug = true;\n");
+
+        JSONObject defaults = new JSONObject();
+        JSONObject appConfig = new JSONObject();
+
+        boolean isDebug = !application.isProductionMode();
+        if (isDebug) {
+            defaults.put("debug", true);
         }
+
         page.write("document.write('<iframe tabIndex=\"-1\" id=\"__gwt_historyFrame\" "
                 + "style=\"position:absolute;width:0;height:0;border:0;overflow:"
                 + "hidden;\" src=\"javascript:false\"></iframe>');\n");
-        page.write("document.write(\"<script language='javascript' src='"
-                + widgetsetFilePath + "'><\\/script>\");\n}\n");
 
-        page.write("vaadin.vaadinConfigurations[\"" + appId + "\"] = {");
-        page.write("appUri:'" + appUrl + "', ");
+        defaults.put("appUri", appUrl);
 
-        page.write(ApplicationConnection.ROOT_ID_PARAMETER + ": "
-                + root.getRootId() + ", ");
+        appConfig
+                .put(ApplicationConnection.ROOT_ID_PARAMETER, root.getRootId());
 
         if (isStandalone()) {
-            page.write("standalone: true, ");
+            defaults.put("standalone", true);
         }
-        page.write("themeUri:");
-        page.write(themeUri != null ? "\"" + themeUri + "\"" : "null");
-        page.write(", versionInfo : {vaadinVersion:\"");
-        page.write(AbstractApplicationServlet.VERSION);
-        page.write("\",applicationVersion:\"");
-        page.write(JsonPaintTarget.escapeJSON(application.getVersion()));
-        page.write("\"}");
+
+        appConfig.put("themeUri", themeUri);
+
+        JSONObject versionInfo = new JSONObject();
+        versionInfo.put("vaadinVersion", AbstractApplicationServlet.VERSION);
+        versionInfo.put("applicationVersion", application.getVersion());
+        appConfig.put("versionInfo", versionInfo);
+
         if (systemMessages != null) {
             // Write the CommunicationError -message to client
-            String caption = systemMessages.getCommunicationErrorCaption();
-            if (caption != null) {
-                caption = "\"" + JsonPaintTarget.escapeJSON(caption) + "\"";
-            }
-            String message = systemMessages.getCommunicationErrorMessage();
-            if (message != null) {
-                message = "\"" + JsonPaintTarget.escapeJSON(message) + "\"";
-            }
-            String url = systemMessages.getCommunicationErrorURL();
-            if (url != null) {
-                url = "\"" + JsonPaintTarget.escapeJSON(url) + "\"";
-            }
-
-            page.write(",\"comErrMsg\": {" + "\"caption\":" + caption + ","
-                    + "\"message\" : " + message + "," + "\"url\" : " + url
-                    + "}");
-
-            // Write the AuthenticationError -message to client
-            caption = systemMessages.getAuthenticationErrorCaption();
-            if (caption != null) {
-                caption = "\"" + JsonPaintTarget.escapeJSON(caption) + "\"";
-            }
-            message = systemMessages.getAuthenticationErrorMessage();
-            if (message != null) {
-                message = "\"" + JsonPaintTarget.escapeJSON(message) + "\"";
-            }
-            url = systemMessages.getAuthenticationErrorURL();
-            if (url != null) {
-                url = "\"" + JsonPaintTarget.escapeJSON(url) + "\"";
-            }
-
-            page.write(",\"authErrMsg\": {" + "\"caption\":" + caption + ","
-                    + "\"message\" : " + message + "," + "\"url\" : " + url
-                    + "}");
+            JSONObject comErrMsg = new JSONObject();
+            comErrMsg.put("caption",
+                    systemMessages.getCommunicationErrorCaption());
+            comErrMsg.put("message",
+                    systemMessages.getCommunicationErrorMessage());
+            comErrMsg.put("url", systemMessages.getCommunicationErrorURL());
+
+            defaults.put("comErrMsg", comErrMsg);
+
+            JSONObject authErrMsg = new JSONObject();
+            authErrMsg.put("caption",
+                    systemMessages.getAuthenticationErrorCaption());
+            authErrMsg.put("message",
+                    systemMessages.getAuthenticationErrorMessage());
+            authErrMsg.put("url", systemMessages.getAuthenticationErrorURL());
+
+            defaults.put("authErrMsg", authErrMsg);
         }
-        page.write("};\n//]]>\n</script>\n");
 
-        if (themeName != null) {
-            // Custom theme's stylesheet, load only once, in different
-            // script
-            // tag to be dominate styles injected by widget
-            // set
-            page.write("<script type=\"text/javascript\">\n");
-            page.write("//<![CDATA[\n");
-            page.write("if(!vaadin.themesLoaded['" + themeName + "']) {\n");
-            page.write("var stylesheet = document.createElement('link');\n");
-            page.write("stylesheet.setAttribute('rel', 'stylesheet');\n");
-            page.write("stylesheet.setAttribute('type', 'text/css');\n");
-            page.write("stylesheet.setAttribute('href', '" + themeUri
-                    + "/styles.css');\n");
-            page.write("document.getElementsByTagName('head')[0].appendChild(stylesheet);\n");
-            page.write("vaadin.themesLoaded['" + themeName + "'] = true;\n}\n");
-            page.write("//]]>\n</script>\n");
+        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(");
+        if (isDebug) {
+            page.write(defaults.toString(4));
+        } else {
+            page.write(defaults.toString());
         }
+        page.write(");\n");
 
-        // Warn if the widgetset has not been loaded after 15 seconds on
-        // inactivity
-        page.write("<script type=\"text/javascript\">\n");
-        page.write("//<![CDATA[\n");
-        page.write("setTimeout('if (typeof " + widgetset.replace('.', '_')
-                + " == \"undefined\") {alert(\"Failed to load the widgetset: "
-                + widgetsetFilePath + "\")};',15000);\n" + "//]]>\n</script>\n");
+        page.write("vaadin.initApplication(\"");
+        page.write(appId);
+        page.write("\",");
+        if (isDebug) {
+            page.write(appConfig.toString(4));
+        } else {
+            page.write(appConfig.toString());
+        }
+        page.write(");\n");
+        page.write("//]]>\n</script>\n");
     }
 
     protected abstract String getApplicationOrSystemProperty(
@@ -439,8 +427,8 @@ public abstract class AjaxPageHandler implements RequestHandler {
 
     protected void writeError(WrappedResponse response, Throwable e)
             throws IOException {
-        response.setStatus(500);
-        response.getWriter().println("Error");
+        response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
+                e.getLocalizedMessage());
     }
 
 }