How to change the main view of a Vaadin 7 application? - vaadin

Question

I want to write a Vaadin 7 application (see MyVaadinUI below), which asks the user to enter user name and password.
If they are correct, another view (see MainUI below) should appear and take the entire area (replace the login view).
I tried to implement this transition in the method MyVaadinUI.goToMainWindow, but I get the error
java.lang.RuntimeException: Component must be attached to a session when getConnectorId() is called for the first time
at com.vaadin.server.AbstractClientConnector.getConnectorId(AbstractClientConnector.java:417)
at com.vaadin.server.communication.ConnectorHierarchyWriter.write(ConnectorHierarchyWriter.java:67)
at com.vaadin.server.communication.UidlWriter.write(UidlWriter.java:143)
at com.vaadin.server.communication.UidlRequestHandler.writeUidl(UidlRequestHandler.java:149)
at com.vaadin.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:97)
at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:37)
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1371)
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:238)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:848)
when I run the application and press the button.
How can I fix it?
#Theme("mytheme")
#SuppressWarnings("serial")
public class MyVaadinUI extends UI
{
private TextField userNameTextField;
private PasswordField passwordTextField;
#WebServlet(value = "/*", asyncSupported = true)
#VaadinServletConfiguration(productionMode = false, ui = MyVaadinUI.class, widgetset = "ru.mycompany.vaadin.demo.AppWidgetSet")
public static class Servlet extends VaadinServlet {
}
#Override
protected void init(VaadinRequest request) {
final VerticalLayout layout = new VerticalLayout();
layout.setMargin(true);
setContent(layout);
addUserNameTextField(layout);
addPasswordTextField(layout);
addButton(layout, request);
}
private void addPasswordTextField(Layout aLayout) {
passwordTextField = new PasswordField("Пароль:");
aLayout.addComponent(passwordTextField);
}
private void addUserNameTextField(final Layout aLayout) {
userNameTextField = new TextField("Пользователь:");
aLayout.addComponent(userNameTextField);
}
private void addButton(final Layout aParent, final VaadinRequest request) {
final Button button = new Button("Войти");
button.addClickListener(new Button.ClickListener() {
public void buttonClick(Button.ClickEvent event) {
final boolean credentialsCorrect = checkCredentials();
if (credentialsCorrect) {
goToMainWindow(request);
} else {
[...]
}
}
});
aParent.addComponent(button);
}
private void goToMainWindow(final VaadinRequest aRequest) {
final MainUI mainUI = new MainUI();
mainUI.init(aRequest);
setContent(mainUI);
}
}
#Theme("mytheme")
#SuppressWarnings("serial")
public class MainUI extends UI {
#Override
protected void init(final VaadinRequest vaadinRequest) {
final HorizontalSplitPanel splitPanel = new HorizontalSplitPanel();
setContent(splitPanel);
splitPanel.setSizeFull();
splitPanel.setSplitPosition(200, Unit.PIXELS);
final String[] tabLabels = new String[] {
"Tree item 1",
"Tree item 2"};
final Tree tree = new Tree();
for (int i=0; i < tabLabels.length; i++)
{
addTreeItem(tree, tabLabels[i]);
}
splitPanel.setFirstComponent(tree);
splitPanel.setSecondComponent(new Label("Test"));
}
private void addTreeItem(final Tree aTree, final String aLabel) {
aTree.addItem(aLabel);
}
}

Answer 1

On the Vaadin forum someone suggested to use the navigator, which solved my problem.

Answer 2

I'd rather think that MainUI should extend HorizontalSplitPanel, not UI. It is strange concept to me to insert one UI into another.

Answer 3

You can use #SpringUI for the main class which extends UI:
#SpringUI
#Theme("mytheme")
#Widgetset("com.MyAppWidgetset")
#PreserveOnRefresh
public class MainUI extends UI {
private static final long serialVersionUID = -8247521108438815011L;
private static Locale locale = VaadinSession.getCurrent().getLocale();
#Autowired
private ToolBoxMessageSource messageSource;
#Autowired
private SpringViewProvider springViewProvider;
public MainUI() {
}
//Initializes navigator with SpringViewProvider and add all existing
//and ui specific assigned views to navigator.
#Override
protected void init(VaadinRequest vaadinRequest) {
Navigator navigator = new Navigator(this, this);
// Adding springViewProvider for spring autowiring
navigator.addProvider(springViewProvider);
// Adding all views for navigation
navigator.addView(LoginView.NAME, LoginView.class);
navigator.addView(MainView.NAME, MainView.class);
navigator.addView(MailToolView.NAME, MailToolView.class);
navigator.addView(AdminView.NAME, AdminView.class);
navigator.addView(EditRecipientView.NAME, EditRecipientView.class);
navigator.addView(EditRecipientsView.NAME, EditRecipientsView.class);
navigator.addView(ServerView.NAME, ServerView.class);
navigator.addView(TestJobView.NAME, TestJobView.class);
navigator.addView("", new LoginView());
navigator.navigateTo(LoginView.NAME);
navigator.setErrorView(LoginView.class);
// security: if user changes view check if the user has the required rights
navigator.addViewChangeListener(new ViewChangeListener() {
private static final long serialVersionUID = 7330051193056583546L;
#Override
public boolean beforeViewChange(ViewChangeEvent event) {
Toolbox toolbox = getSession().getAttribute(Toolbox.class);
if (TbRightManagement.checkAccess(event.getNewView().getClass(), toolbox)) {
return true;
} else {
if (toolbox != null) {
TBNotification.show(messageSource.getMessage("access.denied.title", locale),
messageSource.getMessage("access.denied.no_permissions.msg", locale),
Type.ERROR_MESSAGE);
navigator.navigateTo(MainView.NAME);
return false;
} else {
TBNotification.show(messageSource.getMessage("access.denied.title", locale),
messageSource.getMessage("access.denied.not_loggedin.msg", locale),
Type.ERROR_MESSAGE);
navigator.navigateTo(LoginView.NAME);
return false;
}
}
}
#Override
public void afterViewChange(ViewChangeEvent event) {}
});
}
}
And for the other views, as an example EditRecipientsView should be a #SpringView which extends a Vaadin Designer and implements a Vaadin View.
#SpringView(name = EditRecipientsView.NAME)
#Theme("mytheme")
#TbRight(loggedIn = true, mailTool = true)
public class EditRecipientsView extends RecipientsDesign implements View {
private static final long serialVersionUID = 1L;
public static final String NAME = "editRecipients";
private static Locale locale = VaadinSession.getCurrent().getLocale();
private BeanItemContainer<Recipient> recipientContainer;
private Uploader uploader;
#Autowired
private ToolBoxMessageSource messageSource;
public EditRecipientsView() {
super();
}
//Initializes the ui components of the recipient view.
#PostConstruct
public void init() {
btn_addRecipient.addClickListener(e -> { MainUI.getCurrent().getNavigator().navigateTo(EditRecipientView.NAME);});
}
//Handling data when entering this view.
#Override
public void enter(ViewChangeEvent event) {
if (getSession().getAttribute(UIMailing.class) != null) {
List<Recipient> recipientList = getSession().getAttribute(UIMailing.class).getRecipients();
if (recipientList != null) {
recipientContainer.removeAllItems();
} else {
recipientList = new ArrayList<Recipient>();
}
recipientContainer.addAll(recipientList);
recipient_table.sort(new Object[] {"foreName", "lastName"}, new boolean[] {true, true});
}
}
}