Context: In a Vaadin 23 application there is a form that is reachable directly via URL. It registers a BeforeLeaveListener with UI.getCurrent().addBeforeLeaveListener(bll);. The implementation of the BeforeLeaveListener is this:
#Override
public void beforeLeave(BeforeLeaveEvent event) {
ContinueNavigationAction action = event.postpone();
askAndProceedIfOk(() -> {action.proceed();});
}
It explicitly postpones the BeforeLeaveEvent and explicitly proceeds the event.
In the application there's a second form that is opened in a modal dialog with the option to close it.
Dialog modalDialog = new Dialog();
modalDialog.setCloseOnEsc(true);
modalDialog.setCloseOnOutsideClick(true);
modalDialog.setModal(true);
The BeforeLeaveListener doesn't work here, but a ComponentEventListener<Dialog.DialogCloseActionEvent> does:
modalDialog.addDialogCloseActionListener(new ComponentEventListener<Dialog.DialogCloseActionEvent>() {
#Override
public void onComponentEvent(Dialog.DialogCloseActionEvent event) {
myForm.askAndProceedIfOk(() -> {modalDialog.close();});
}
});
Surprise: I am surprised that BeforeLeaveEvent and DialogCloseActionEvent work different:
BeforeLeaveEvent offers postpone() and proceed()
DialogCloseActionEvent seems to be implicitly postponed just by showing another modal Dialog that asks the user whether to save unsaved changes. And I do have to close the modal dialog explicitly.
Question: Is it right that both events (with a similar task) work that different or do I miss some details here?
Related
My question stems from an issue almost identical to the one here (which did not end up getting a satisfactory answer):
https://vaadin.com/forum/thread/13932610
Like this person, I expected that upon closing the browser that my app was open in, a detach event would proc; however, this did not happen. I've tried adding a detach listener, overriding the detach method, and doing both at the same time, but none of them were successful. As for how I know the detach event was not called, my detach event is a simple print statement - that does not show up in the output.
Note that like in the aforementioned thread, I've already set the heartbeat interval (2 seconds in my case) and set closeIdelSessions to be true. So, I thought I would just have to wait six seconds, but that's certainly not been the case.
When I try this (find the essential parts of the code below), the detach() is eventually being called. I run this with Jetty, and I did not touch its default. It tooks some ~45 minutes after closing the Browser, when I saw "Detach called" logged on console. So yes, the time is lengthy. The reason is that the last UI is cleaned up only after HttpSession is expired (which depends on application container etc. settings). If you want to do forced clean up quicker, you need to use https://vaadin.com/directory/component/cleanupservlet-add-on
#Push
#SuppressWarnings("serial")
public class DemoUI extends UI {
#WebServlet(value = "/*", asyncSupported = true)
#VaadinServletConfiguration(productionMode = false, ui = DemoUI.class, heartbeatInterval=5, closeIdleSessions=true)
public static class Servlet extends VaadinServlet {
}
#Override
public void detach() {
System.out.println("Detach called");
}
#Override
protected void init(VaadinRequest vaadinRequest) {
...
}
I have the following snippet in my UI Builder code:
table.addShortcutListener(new ShortcutListener("Select all", null, KeyCode.A, ModifierKey.CTRL) {
#Override
public void handleAction(Object sender, Object target) {
AbstractSelect t = (AbstractSelect) target;
if (t.isMultiSelect()) {
t.setValue(t.getItemIds());
}
}
});
return table;
This allows to press Ctrl+A to select all items in a table. This usually works the first time I load a view until I make one of the tables invisible (setVisible(false)). After making the tables visible again, it no longer works (not even on reloading the page) and I get the following console output whenever I press Ctrl+A:
WARNING: Ignoring action for disabled connector c.b.a.web.ui.builder.table.TranslatedHeaderTable
Nov 03, 2014 11:15:00 AM com.vaadin.event.ConnectorActionManager handleAction
What is wrong with my code? How would I achieve my goal?
I'd suggest this modification, works fine for me (i suppose comp is the Vaadin Table)
comp.addShortcutListener(new ShortcutListener("Select all", null, KeyCode.A, ModifierKey.CTRL) {
private static final long serialVersionUID = 1L;
#Override
public void handleAction(Object sender, Object target) {
if (comp.isMultiSelect()) {
comp.setValue(comp.getItemIds());
}
}
});
The problem might be, while testing locally, the failure of serialization of some component, so a static reference to comp (you'll need to make it final) and a defaut UID should do the trick.
tested multiple times and the error never occured.
Cheers.
EDIT
I understood that the problem occured when making invisible and then visible the table.
It came to my mind just now that you could have tried CTRL+A on an invisible Table: if this is the case so it's correct, when a Component is made invisible every listener is put in "Standby" until you make it visible again. So for me:
setVisible(false);
setVisible(true);
"CTRL+A"
works, while
setVisible(false);
"CTRL+A"
gives me
nov 03, 2014 2:19:34 PM com.vaadin.event.ConnectorActionManager handleAction
WARNING: Ignoring action for disabled connector com.vaadin.ui.Table
It's meant to be this way, nothing wrong in your code, you have to change your functionality and do not have a "CTRL+A" on an invisible Table (which seems a bad thing to do imho). On the other hand you could overwrite the setVisible method but I discourage it.
Cheers.
It seems there are some problems with the Table implementation of the Action.Notifier interface. In this Vaadin Forum Post, the Vaadin Devs suggest to add the ShortcutListener not to the Table itself but to a Panel that the Table is enclosed within.
My new implementation:
private void addCtrlAHandler(final AbstractSelect table) {
Panel panelEnclosingTable = table.findAncestor(Panel.class);
Preconditions.checkArgument(panelEnclosingTable != null, "Table is not enclosed in a panel; cannot add shortcut handlers");
panelEnclosingTable.addShortcutListener(new ShortcutListener("Select all", null, KeyCode.A, ModifierKey.CTRL) {
#Override
public void handleAction(Object sender, Object target) {
if (table.isMultiSelect()) {
table.setValue(table.getItemIds());
}
}
});
}
With this workaround, I get the expected behavior.
I have a simple UI class
public class HelloWorldUI extends UI {
#Override
protected void init(VaadinRequest request) {
System.out.println("Initialized !");
final VerticalLayout layout = new VerticalLayout();
layout.addComponent(new Label("Hello World !"));
setContent(layout);
}
#Override
public void detach() {
System.out.println("Detach !");
super.detach();
}
#Override
public void attach() {
System.out.println("Attach !");
super.attach();
}
}
When first time my UI was loaded , I see outputs at my console as
Attach !
Initialized !
It is OK and this is what I expected. But when I refresh the browser , my console outputs were
Attach !
Initialized !
Detach !
Amazing ! I think Detach ! may be produce first because (as I think) when browser was refreshed , detach() method should be call and attach() , init() should be follow . But actually detach() method will call after attach() method. What's wrong my thinking ?
Browser Refresh = New UI Instance
When you refresh a browser window or tab, a new UI instance is created. So you see an attach message of a new UI instance. The old UI instance will be detached later.
This is default behavior in Vaadin 7. You may change that behavior with an annotation.
#PreserveOnRefresh
Adding #PreserveOnRefresh annotation to the UI changes the behavior: No new UI instance won't be created on refresh.
To quote the doc for this annotation:
Marks a UI that should be retained when the user refreshed the browser window. By default, a new UI instance is created when refreshing, causing any UI state not captured in the URL or the URI fragment to get discarded. By adding this annotation to a UI class, the framework will instead reuse the current UI instance when a reload is detected.
I have a background function listening for push messages. I need to handle though the push. I created the function to take any actions when the push arrives and it works pretty well. For example when a push arrives i increment a number etc etc.
However what would be the code to actually make the application start , when the user presses ok to the push?
I just need to make the application start normally , like the user just pressed on the icon of the app.
I am using OS < 7.X
One typical pattern is to build an application that has two entry points. That is, it can be started in two different ways. One way, would be the normal UiApplication. That's the standard BlackBerry app that can be started with a home screen icon press.
The other way would be to define a background service, that handles push notifications, and is started by the OS as soon as the device boots.
You'll define the background/push entry point by adding an Alternate Entry Point in your app's BlackBerry_App_Descriptor.xml file. Make sure to check Auto-run at Startup and Do not display the application icon .... Your app descriptor xml file should then contain something like this, in addition to the normal entry point for the UiApplication:
<AlternateEntryPoints>
<AlternateEntryPoint Title="PushService" MainMIDletName=""
ArgumentsForMain="-push" HomeScreenPosition="0"
StartupTier="7" IsSystemModule="true"
IsAutostartup="true" hasTitleResource="false"
TitleResourceBundleKey="" TitleResourceBundleName=""
TitleResourceBundleClassName="" TitleResourceBundleRelativePath="">
<Icons/>
<KeywordResources KeywordResourceBundleName="" KeywordResourceBundleRelativePath="" KeywordResourceBundleClassName="" KeywordResourceBundleKey=""/>
</AlternateEntryPoint>
</AlternateEntryPoints>
Then, you'll have a main program like this:
public class MyApp extends UiApplication
public static void main(String[] args) {
if (args.length > 0 && args[0].equals("-push")) {
// this is the push service
PushAgent pa = new PushAgent();
pa.enterEventDispatcher();
} else {
// UiApplication
MyApp app = new MyApp();
app.enterEventDispatcher();
}
}
}
Where PushAgent is a class that extends Application, not UiApplication.
Then, when your push agent receives a notification and you decide you want to show the UI, use something like this:
ApplicationDescriptor ad = ApplicationDescriptor.currentApplicationDescriptor();
// String[] used for command line args, but we don't pass any to the UI app
ApplicationDescriptor ui = new ApplicationDescriptor(ad, new String[] { });
ApplicationManager.getApplicationManager().runApplication(ui);
try this -
When you click the ok button use the following code to run your ui application.
public void dialogClosed(Dialog dialog, int choice) {
switch (choice) {
case Dialog.OK:
try {
ApplicationDescriptor[] appDescriptors =CodeModuleManager.getApplicationDescriptors(CodeModuleManager.getModuleHandle("BlackBerryCity")); //here BlackBerryCity is the COD module Name
ApplicationDescriptor appDescriptor = new ApplicationDescriptor(appDescriptors[0], new String[] {"BlackBerryCity"});
ApplicationManager.getApplicationManager().runApplication(appDescriptor);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
break;
case Dialog.CANCEL:
break;
default:
break;
}
}
class EntryPointForApplication extends UiApplication {
private static EntryPointForApplication theApp;
public EntryPointForApplication() {
GUIApplication scr = new GUIApplication();
pushScreen(scr);
}
}
Read this also How to setup alternate entry point in Blackberry application?
For sake of completeness here are all the options that you can use to launch an application:
I am assuming that you already have multiple entry points - one for the background listener and one for the UI Application. Also assuming that you are not passing any Application Arguments for the UI App. (See Nate's answer for full description of how to do this.)
Using runApplication() method:
ApplicationDescriptor ad = ApplicationDescriptor.currentApplicationDescriptor();
// String[] used for command line args, but we don't pass any to the UI app
ApplicationDescriptor ui = new ApplicationDescriptor(ad, new String[] { });
//Launch the application and ask it to come in foreground
ApplicationManager.getApplicationManager().runApplication(ui, true);
Using launch() method:
String modulename = "mymodule";
ApplicationManager.launch(modulename);
Using launchApplication() method:
String modulename = "mymodule";
ApplicationManager.launchApplication(modulename);
One thing to note is that if your UI app is already open, all these methods will simply bring it to foreground in whatever condition it it. If you require the click of button to open a new instance of your app, you will have to pass some random parameter as the application arguments and then ignore it in the main method.
We are currently facing one problem in our portlet-environment using JSF2.
The application is creating dynamic portal-pages for the actual user session...think of it as Eclipse editor-views where the user can edit entities. So for now I call the dynamic-views editors :-)
The problem we are facing now, is following. The user navigates to a editor and works on the portlet(s). The displayed views in each portlet change over time of course. Now he wants to have a look on another entity which is displayed in another editor. But when he navigates back to the first editor, the state of portlets changes back to the default views.
In the portlet-world each portlet each portlet gets the view it should display via a parameter which is stored in the PortletSession and I can easily change that parameter as well. I know that this parameter is causing the trouble because when the changes the editors, the portlets will always check this parameter to decide which view to show.
request.getPortletSession().setAttribute("com.ibm.faces.portlet.page.view", "/MyPage.xhtml");
My idea was, to somehow add a callback to each JSF-navigation which will set this parameter to the view the navigation is going to display (possibly including view-params).
Is it possible to have a standard callback? If not, would be possible to execute some kind of EL in the navigation-rule that will set this parameter?
somehow add a callback to each JSF-navigation
You could perform the job in a custom ConfigurableNavigationHandler. Here's a kickoff example:
public class MyNavigationHandler extends ConfigurableNavigationHandler {
private NavigationHandler parent;
public MyNavigationHandler(NavigationHandler parent) {
this.parent = parent;
}
#Override
public void handleNavigation(FacesContext context, String from, String outcome) {
// TODO: Do your job here.
// Keep the following line untouched. This will perform the actual navigation.
parent.handleNavigation(context, from, outcome);
}
#Override
public NavigationCase getNavigationCase(FacesContext context, String fromAction, String outcome) {
return (parent instanceof ConfigurableNavigationHandler)
? ((ConfigurableNavigationHandler) parent).getNavigationCase(context, fromAction, outcome)
: null;
}
#Override
public Map<String, Set<NavigationCase>> getNavigationCases() {
return (parent instanceof ConfigurableNavigationHandler)
? ((ConfigurableNavigationHandler) parent).getNavigationCases()
: null;
}
}
To get it to run, register it as follows in faces-config.xml:
<application>
<navigation-handler>com.example.MyNavigationHandler</navigation-handler>
</application>