how to use callback in GWT ListGrid.exportdata - java

btnDownloadExcel.addClickHandler(new ClickHandler()
{
public void onClick(ClickEvent event)
{
ApplicationController.isLogout = false;
final ProgressBarWindow progressBarWindow = newProgressBarWindow();
DSRequest dsRequestProperties = new DSRequest();
dsRequestProperties.setExportAs((ExportFormat)
ExportFormat.OOXML);
dsRequestProperties.setExportDatesAsFormattedString(true);
dsRequestProperties.setExportResults(true);
dsRequestProperties.setExportToClient(true);
dsRequestProperties.setExportFilename("DownloadLogs.xlsx");
String title = "Export log";
String message = "Exporting data...";
progressBarWindow.setShowMinimizeButton(false);
progressBarWindow.setIsModal(true);
progressBarWindow.setShowModalMask(true);
progressBarWindow.initiate(title, message);
mainGrid.exportData(dsRequestProperties);
progressBarWindow.show();
Timer timer = new Timer() {
#Override
public void run(){
progressBarWindow.hide();
}
};
timer.schedule(50000);
}
});
hstack.addMember(btnDownloadExcel);
return hstack;
Instead of Timer, I want to use callback to hide the progress bar
once export document is done. Timer is not hiding progress bar on time.

I don't think you can do it like that.
The docs for the callback parameter of exportData says:
Note that this parameter only applies where DSRequest.exportToClient is explicitly set to false, because file downloads do not provide ordinary SmartClient callbacks
I think that the only way to do it is using a 'server push' mechanism, for example the RealtimeMessaging module of SmartGWT

Related

Vaadin: Cannot get progress dialog to receive/react when the task completes

I've written a small Spring Boot/Vaadin application that displays a simple UI to take user input and make a call to another service that takes some time to run. When the task is submitted, I'm displaying a progress dialog that shows a progress bar, a message informing the user what is going on and a close button to allow them to close the dialog when the job completes. I'm using a ListenableFuture to be notified when the task is done.
I can get the dialog to appear with status of "executing" and the progress bar doing its thing, but when the task is done (I have debug statements going to the console to let me know), it's not triggering the logic to update the status message and enable the close button. I can't figure out what I'm doing wrong.
Here's the code:
MainView1.java
#Route("rescheduleWorkOrders1")
#CssImport("./styles/shared-styles.css")
public class MainView1 extends VerticalLayout {
...
private final BackendService service;
public MainView1(BackendService service) {
this.service = service;
configureView();
addSubmitButton();
bindFields();
}
private void addSubmitButton() {
Button submit = new Button("Submit", this::submit);
add(submit);
}
private void submit(ClickEvent<?> event) {
UserData data = binder.getBean();
ListenableFuture<ResponseEntity<String>> future = service.executeTask(data);
ProgressDialog dialog = new ProgressDialog(future);
dialog.open();
}
private void configureView() {
...
}
private void bindFields() {
...
}
}
ProgressDialog.java
public class ProgressDialog extends Dialog {
private final ListenableFuture<ResponseEntity<String>> future;
private ProgressBar bar;
private Paragraph message;
private Button close;
public ProgressDialog(ListenableFuture<ResponseEntity<String>> future) {
super();
this.future = future;
configureView();
this.future.addCallback(new ListenableFutureCallback<>() {
#Override
public void onSuccess(ResponseEntity<String> result) {
message.setText("Task complete. Status: " + result.getStatusCode());
bar.setVisible(false);
close.setEnabled(true);
}
#Override
public void onFailure(Throwable ex) {
message.setText(ex.getMessage());
bar.setVisible(false);
close.setEnabled(true);
}
});
}
private void configureView() {
bar = new ProgressBar();
bar.setIndeterminate(true);
bar.setVisible(true);
message = new Paragraph("Executing task ...");
close = new Button("Close", this::close);
close.setEnabled(false);
add(bar, message, close);
}
private void close(ClickEvent<?> event) {
this.close();
}
}
BackendService.java
#Service
public class BackendService {
#Async
public ListenableFuture<ResponseEntity<String>> executeTask(UserData data) {
...
RestTemplate template = new RestTemplate();
ResponseEntity<String> response = template.postForEntity(uri, entity, String.class);
System.out.println(response);
return AsyncResult.forValue(response);
}
}
Note: I do have #EnableAsync specified in a #Configuration annotated class.
When dealing with asynchronous code in Vaadin you need to:
Use UI#access when updating the UI outside an active request. This acquires a lock on the UI, to prevent it being updated by two threads simultaneously.
Enable server push by adding the #Push annotation to your main layout or view. This allows the server to push updates to the client even if no request is active.
Without the former, you can get ConcurrentModificationExceptions in the best case, and very subtle bugs in the worst.
Without the latter, the changes will be applied (i.e. dialog closed), but the changes will only be sent to the client the next time the client sends a request. I believe this is your main issue.
More information can be found in the documentation.

Progress indicator remains indeterminate and there is no download

I have written a piece of code for downloading a file from internet (in background service) and showing the progress of download in a popup stage. The code compiles successfully and there is no runtime error. However no download takes place and progress indicator remains indeterminate.
The code is tailored for illustrating my point. Please have a look at it and let me understand where I have gone wrong.
Thanks!
public class ExampleService extends Application {
URL url;
Stage stage;
public void start(Stage stage)
{
this.stage = stage;
stage.setTitle("Hello World!");
stage.setScene(new Scene(new StackPane(addButton()), 400, 200));
stage.show();
}
private Button addButton()
{
Button downloadButton = new Button("Download");
downloadButton.setOnAction(new EventHandler<ActionEvent>()
{
public void handle(ActionEvent e)
{
FileChooser fileSaver = new FileChooser();
fileSaver.getExtensionFilters().add(new FileChooser.ExtensionFilter("PDF", "pdf"));
File file = fileSaver.showSaveDialog(stage);
getDownloadService(file).start();
}
});
return downloadButton;
}
private Service getDownloadService(File file)
{
Service downloadService = new Service()
{
protected Task createTask()
{
return doDownload(file);
}
};
return downloadService;
}
private Task doDownload(File file)
{
Task downloadTask = new Task<Void>()
{
protected Void call() throws Exception
{
url = new URL("http://www.daoudisamir.com/references/vs_ebooks/html5_css3.pdf");
// I have used this url for this context only
org.apache.commons.io.FileUtils.copyURLToFile(url, file);
return null;
}
};
showPopup(downloadTask);
return downloadTask;
}
Popup showPopup(Task downloadTask)
{
ProgressIndicator progressIndicator = new ProgressIndicator();
progressIndicator.progressProperty().bind(downloadTask.progressProperty());
Popup progressPop = new Popup();
progressPop.getContent().add(progressIndicator);
progressPop.show(stage);
return progressPop;
// I have left out function to remove popup for simplicity
}
public static void main(String[] args)
{
launch(args);
}}
The line:
org.apache.commons.io.FileUtils.copyURLToFile(url, file);
...doesn't provide you any information about the progress of your download (there is no callback or any other indication of its progress). It just downloads something without giving you feedback.
You will have to use something else that gives you feedback on the progress.
Take a look at this questions answers for solutions with feedback (it is for Swing, but you should be able to adapt them for JavaFX): Java getting download progress
You bind the ProgressIndicator's progress property to the Task's progress property, so that changes in the latter will be reflected in the former. However you never actually update your Task's progress.
If you want the progress indicator to show something, you're going to have to call updateProgress(workDone, max) within your task's body (or elsewhere). And that might be tricky if the download logic you're using doesn't give you any progress callbacks. (You could, perhaps, spawn a thread to repeatedly check the size of the file on the filesystem and use that as your current workDone; but you'd need to know what the eventual/complete size of the file would be in order to turn this into a percentage, which may or may not be easy.)

Matlab & Java: Execute matlab asynchronously

so, here is my today problem:
First of all, please note that I do NOT have the Matlab parallel toolbox available.
I am running java code witch interact with Matlab. Sometime Matlab directly call some java functions, sometimes it is the opposite. In this case, we use a notification system which comes from here:
http://undocumentedmatlab.com/blog/matlab-callbacks-for-java-events
We then address the notification in proper callbacks.
Here is a simple use case:
My user select a configuration file using the java interface, loaded into Matlab.
Using an interface listener, we notify Matlab that the configuration file has been selected, it then run a certain number of functions that will analyzes the file
Once the analysis is done, it is pushed into the java runtime, which will populate interface tables with the result. This step involve that matlab will call a java function.
Finally, java request the interface to be switched to an arbitrary decided tab.
This is the order of which things would happen in an ideal world, however, here is the code of the listener actionPerformed method:
#Override
public void actionPerformed(ActionEvent arg0) {
Model wModel = controller.getModel();
Window wWindow = controller.getWindow();
MatlabStructure wStructure = new MatlabStructure();
if(null != wModel) {
wModel.readMatlabData(wStructure);
wModel.notifyMatlab(wStructure, MatlabAction.UpdateCircuit);
}
if(null != wWindow) {
wWindow.getTabContainer().setSelectedComponent(wWindow.getInfosPannel());
}
}
What happen here, is that, when the notifyMatlab method is called, the code does not wait for it to be completed before it continues. So what happen is that the method complete and switch to an empty interface page (setSelectedComponent), and then the component is filled with values.
What I would like to, is for java to wait that my notifyMatlab returns a "I have completed !!" signal, and then pursue. Which involves asynchrounous code since Matlab will code java methods during its execution too ...
So far here is what I tried:
In the MatlabEventObject class, I added an isAcknowledge member, so now the class (which I originaly found in the above link), look like this (I removed all unchanged code from the original class):
public class MatlabEventObject extends java.util.EventObject {
private static final long serialVersionUID = 1L;
private boolean isAcknowledged = false;
public void onNotificationReceived() {
if (source instanceof MatlabEvent) {
System.out.println("Catched a MatlabEvent Pokemon !");
MatlabEvent wSource = (MatlabEvent) source;
wSource.onNotificationReceived();
}
}
public boolean isAcknowledged() {
return isAcknowledged;
}
public void acknowledge() {
isAcknowledged = true;
}
}
In the MatlabEvent class, I have added a future task which goal is to wait for acknowledgement, the methods now look like this:
public class MatlabEvent {
private Vector<IMatlabListener> data = new Vector<IMatlabListener>();
private Vector<MatlabEventObject> matlabEvents = new Vector<MatlabEventObject>();
public void notifyMatlab(final Object obj, final MatlabAction action) {
final Vector<IMatlabListener> dataCopy;
matlabEvents.clear();
synchronized (this) {
dataCopy = new Vector<IMatlabListener>(data);
}
for (int i = 0; i < dataCopy.size(); i++) {
matlabEvents.add(new MatlabEventObject(this, obj, action));
((IMatlabListener) dataCopy.elementAt(i)).testEvent(matlabEvents.get(i));
}
}
public void onNotificationReceived() {
ExecutorService service = Executors.newSingleThreadExecutor();
long timeout = 15;
System.out.println("Executing runnable.");
Runnable r = new Runnable() {
#Override
public void run() {
waitForAcknowledgement(matlabEvents);
}
};
try {
Future<?> task = service.submit(r);
task.get(timeout, TimeUnit.SECONDS);
System.out.println("Notification acknowledged.");
} catch (Exception e) {
e.printStackTrace();
}
}
private void waitForAcknowledgement(final Vector<MatlabEventObject> matlabEvents) {
boolean allEventsAcknowledged = false;
while(!allEventsAcknowledged) {
allEventsAcknowledged = true;
for(MatlabEventObject eventObject : matlabEvents) {
if(!eventObject.isAcknowledged()) {
allEventsAcknowledged = false;
}
break;
}
}
}
}
What happen is that I discover that Matlab actually WAIT for the java code to be completed. So my waitForAcknowledgement method always wait until it timeouts.
In addition, I must say that I have very little knowledge in parallel computing, but I think our java is single thread, so having java waiting for matlab code to complete while matlab is issuing calls to java functions may be an issue. But I can't be sure : ]
If you have any idea on how to solve this issue in a robust way, it will be much much appreciated.

GWT - Methods in onModuleLoad() called multiple times

I'm trying to write a simple application to display chart data. I want to display some data as soon as the user loads the page, so I'm getting data & drawing tables inside of the Runnable as described in the gwt-visualization Getting Started.
Things seem to work alright, except charts tend to get loaded more than once. Below is my onModuleLoad().
private final StatisticsServiceAsync statisticsService = GWT.create(StatisticsService.class);
GWTBeanFactory factory = GWT.create(GWTBeanFactory.class);
DataTable locationData;
AnnotatedTimeLine atl;
GeoMap usMap;
TextBox storeField;
Button log10Button;
DateRange durationChartRange;
String eusrJson = null;
Button b;
HTML last1000Html;
public void onModuleLoad() {
storeField = new TextBox();
storeField.setText("Enter a store");
storeField.addKeyDownHandler(new MyKeyHandler());
b = new Button("Get Stats!");
log10Button = new Button("Show Log10 Scale");
log10Button.addClickHandler(new Log10ClickHandler());
b.addClickHandler(new MyClickHandler());
last1000Html = new HTML();
getLast1000Avg();
Runnable onLoadCallback = new Runnable() {
public void run() {
storeDurationData = DataTable.create();
storeDurationDataLog10 = DataTable.create();
RootPanel.get("storeDurationDiv").add(storeField);
RootPanel.get("storeDurationDiv").add(b);
RootPanel.get("storeDurationDiv").add(log10Button);
RootPanel.get("storeDurationDiv").add(last1000Html);
log10Button.setVisible(false);
// Get initial Data
getAvgByRegion();
getLast1000Avg();
Scheduler.get().scheduleFixedDelay(new RepeatingCommand() {
#Override
public boolean execute() {
getLast1000Avg();
return true;
}
}, 5000);
}
};
// Load the visualization api, passing the onLoadCallback to be called
// when loading is done.
VisualizationUtils.loadVisualizationApi(onLoadCallback, AnnotatedTimeLine.PACKAGE);
VisualizationUtils.loadVisualizationApi(onLoadCallback, GeoMap.PACKAGE);
}
All of the "simple" elements seem to get populated correctly, as the Button, HTML, and TextBox all get placed appropriately (which used to be inside of run, they're where they are now as a result of debugging previous errors). However, the GeoMap gets placed twice, and looking at the logging you can tell that the Runnable's run is being executed at least twice, which seems reasonable, but I don't know how to keep it from adding twice.
I'm probably screwing up something with the Async stuff, but I'm new and confused. Below is my getAvgByRegion() method:
private void getAvgByRegion() {
statisticsService.getEusrForRegion(new AsyncCallback<String>() {
#Override
public void onFailure(Throwable caught) {
System.out.println(":(");
}
#Override
public void onSuccess(String result) {
createLocTable();
DataTable dt = parseEusrLocations(result);
usMap = new GeoMap(dt, createGeoMapOptions());
usMap.setSize("800px", "600px");
RootPanel.get("storeDurationDiv").add(usMap);
}
});
}
Any advice on how best to work with GWT is welcome.
So, you call VisualizationUtils.loadVisualizationApi twice, so the onLoadCallback will be run twice (I don't know GWT Google Apis, this is a supposition).
onLoadCallback calls getAvgByRegion, so that one will get called twice too; and it gets data and in the callback creates a new GeoMap and adds it to the RootPanel.get("storeDurationDiv"), so you get two GeoMaps on the screen.
The other widgets(storeField, etc.) are created only once, so adding them repeatedly is not a problem (except performance-wise), as they'll first be removed from their current parent before being added to the new one (which in this case is the same)

Disable back button in GWT

Is there a way to disable the Back button in a browser (basically clearing the History token stack) in GWT? Once I browse to a certain page in my application I want to make sure that the user can't use the back button to go back, but only be able to use links on the page to navigate the site.
You cannot disable a button just intercept it and change its return to something the browser does not understand.
This removes the history:
Window.addWindowClosingHandler(new ClosingHandler() {
#Override
public void onWindowClosing(ClosingEvent event) {
event.setMessage("My program");
}
});
To understand it see: http://groups.google.com/group/google-web-toolkit/browse_thread/thread/8b2a7ddad5a47af8/154ec7934eb6be42?lnk=gst&q=disable+back+button#154ec7934eb6be42
However, I would recommend not doing this because your it goes against good UI practices. Instead you should figure out a way that the back button does not cause a problem with your code.
Call the method below in the onModuleLoad().
private void setupHistory() {
final String initToken = History.getToken();
if (initToken.length() == 0) {
History.newItem("main");
}
// Add history listener
HandlerRegistration historyHandlerRegistration = History.addValueChangeHandler(new ValueChangeHandler() {
#Override
public void onValueChange(ValueChangeEvent event) {
String token = event.getValue();
if (initToken.equals(token)) {
History.newItem(initToken);
}
}
});
// Now that we've setup our listener, fire the initial history state.
History.fireCurrentHistoryState();
Window.addWindowClosingHandler(new ClosingHandler() {
boolean reloading = false;
#Override
public void onWindowClosing(ClosingEvent event) {
if (!reloading) {
String userAgent = Window.Navigator.getUserAgent();
if (userAgent.contains("MSIE")) {
if (!Window.confirm("Do you really want to exit?")) {
reloading = true;
Window.Location.reload(); // For IE
}
}
else {
event.setMessage("My App"); // For other browser
}
}
}
});
}
I found a way to make GWT ignore the back-button: Just add historyitem x if no historyitem was set and do nothing on x.
set a historyitem on startup
History.newItem("x")
in the ValueChangeHandler of History add the following:
String historyToken = event.getValue();
if (!historyToken.equals("x"))
History.newItem("x");
Window.addWindowClosingHandler(new ClosingHandler() {
#Override
public void onWindowClosing(ClosingEvent event) {
event.setMessage("My program");
}
});
That is not a fool proof solution. In fire fox I can press the back button and the onWindowClosing method is never invoked. The reason is that I have used History.newItem() and since history exists the back button or backspace buttons simply navigate through the browser history.
So....fix that :)
Put this in your index.html file:
window.open('html page(For example trial.html)', 'Name of the desired site', width='whatever you want',height='whatever you want', centerscreen=yes, menubar=no,toolbar=no,location=no,
personalbar=no, directories=no,status=no, resizable=yes, dependent=no, titlebar=no,dialog=no');

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