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Moxieapps file uploader for GWT adding multiple upload buttons

The GWT web app I'm building has a page where users can upload CSV files. The upload code uses the Moxieapps GWT Uploader, which mostly works great.
However, I've discovered a strange scenario, where navigating away from the page and back to it adds the upload button again. So the third time I visit the page, the upload section will look like this:
And the relevant part of the generated HTML viewed in an inspector shows that both the input and the div containing the "button" get added over and over (though there is only ever one dropzone):
I've gone over my code many times to see whether I was doing something that could be causing this, but haven't found anything. You don't actually manually add the button or the input; this is done automatically by the framework. The fileUploader gets initialised only once (this being GWT client code, I've debugged using the inspector as well as logging statements to the console to confirm this):
fileUploader.setButtonDisabled(true).setFileTypes("*.csv")
.setUploadURL(getBaseUrl() + "/fileUpload.upload")
.setButtonText("<span class=\"buttonText\">Select CSV file to upload</span>")
.setFileSizeLimit(FILE_SIZE_LIMIT)
.setButtonCursor(CustomUploader.Cursor.HAND)
.setButtonAction(CustomUploader.ButtonAction.SELECT_FILE)
.setUploadProgressHandler(new UploadProgressHandler() {...})
.setUploadSuccessHandler(...)
// etc. with other handlers
The method setButtonText() is called from a couple of other places, and the text changes as it should, but only on the last button (if there are several). Otherwise, there's nothing in my code that could possibly be adding the button as far as I can tell.
Has anyone else encountered this issue? Is there some property I need to set to prevent this? Could it be a bug in the moxieapps code?

After writing out my question, and adding "Could it be a bug in the moxieapps code?" at the end, I followed up on that suspicion, and it turns out that it is indeed a bug in the org.moxieapps.gwt.uploader.client.Uploader class.
The input and the "select file" button are added in the onLoad() method of that class without a check whether they may have been added already.
It looks like there hasn't been any active development on this framework for some time, so I thought it was time for a custom override version. I've tested this and it works:
package yourpackagename.client.override;
import java.util.Iterator;
import org.moxieapps.gwt.uploader.client.Uploader;
import com.google.gwt.user.client.ui.FileUpload;
import com.google.gwt.user.client.ui.Widget;
import com.google.gwt.user.client.ui.WidgetCollection;
/**
* The sole reason this class exists is to fix a bug in the moxieapps uploader
* (org.moxieapps.gwt.uploader-1.1.0.jar) where it adds a new upload input and
* button each time its <code>onLoad()</code> method is called, i.e. every time
* you navigate away from the page and then back to it.
*/
public class CustomUploader extends Uploader {
#Override
protected void onLoad() {
boolean hasFileUploadAlready = false;
WidgetCollection children = getChildren();
for (Iterator<Widget> iterator = children.iterator(); iterator.hasNext();) {
Widget eachWidget = iterator.next();
if (eachWidget instanceof FileUpload) {
hasFileUploadAlready = true;
}
}
// Only call the super method if there isn't already a file upload input and button
if (!hasFileUploadAlready) {
super.onLoad();
}
}
}
Instead of referencing the org.moxieapps.gwt.uploader.client.Uploader, I've changed the references to point to my custom uploader class, which will now check for an existing FileUpload child widget, and simply skip the original onLoad() code if it finds such a widget.
Might be a bit of a crowbar approach, but it works (and in my case, changing the maven-managed JAR file is not very practical). Hopefully, this will be useful to anyone else coming across this problem.

Custom message when closing a part in Eclipse RCP 4

we have the following problem:
In our Eclipse RCP 4 application there are multiple parts and the parts are closable. When the user is closing a part there should be a custom pop-up (depending on some internal part state) which is asking the user if he really wants to close the part or not.
It seems to be not that easy to implement in Eclipse RCP 4 or we have just totally overseen something.
I'll just give you a short brieifing about the things we tried:
Use dirtable with a #persist method in the part. Though the problem is, we don't want this standard eclipse save dialog. So is there a way to override this?
public int promptToSaveOnClose(): This seemed to be promising but not for Eclipse 4 or is there a way to integrate it that way? Compare: http://e-rcp.blogspot.de/2007/09/prevent-that-rcp-editor-is-closed.html
Our last try was to integrate a custom part listener, simple example shown in the following:
partService.addPartListener(new IPartListener() {
public void partVisible(MPart part) {
}
public void partHidden(MPart part) {
partService.showPart(part, PartState.ACTIVATE);
}
public void partDeactivated(MPart part) {
}
public void partBroughtToTop(MPart part) {
}
public void partActivated(MPart part) {
}
});
The problem with this was we are running into a continuous loop. Something similar is posted over here in the last comment: Detect tab close in Eclipse editor
So I could write some more about this problem, but I think that's enough for the moment. If you need some more input just give me a hint.
Thanks for helping.

The save prompt is generated by the ISaveHandler registered in the context of the MWindow containing the MPart. You can write your own ISaveHandler and set it in the window context to replace the default.
You might also want to look at the IWindowCloseHandler also in the window context.

Thanks greg, this has helped and I was able to achieve changing the pop-up when the user closes a part. Here's a short description of what I've done:
Use the MDirtyable for marking the part as dirty whenever it's needed.
Create a custom save handler which implements ISaveHandler (when a part got closed the save method is called). Add the additional logic to this handler (e.g. a custom message dialog)
Register this handler at application start-up (I just chose a method which is called at the start-up):
#Inject
private MWindow window;
...
ISaveHandler saveHandler = new CustomSaveHandler(shell);
window.getContext().set(ISaveHandler.class, saveHandler);
Note that the registration via a model processor was sadly not that easy because the model processor is called too early. (Take a look at: http://www.eclipse.org/forums/index.php/t/369989/)
The IWindowCloseHandler is just needed when the complete window is closed, though this was not an requirement for us :).

GWT CK EDITOR - Rendering issue

I am using gwt-ckeditor in my application. I am using GWT 2.5 and I have embedded CKEDITOR in GWT. I have some fields in form containing CKEditor as well. When I navigate from one form to another, it does not sustain its value. I dont want to save it. But I want to sustain it atleast for my validations to get complete. How can I acheive this functionality ? Please let me know. As Whenever it is getting detached it is losing its values.

Yeah I was also facing the same issue. CKeditor is actually extended from IFrame and that is why when it is detached from the form or widget, it will loose all the information. To sustain its value , you have to manually code it.
private String ckValue ;
CkEditor ckeditor = new CkEditor(new CkConfig());
ckeditor.addAttachHandler(new AttachHandler(){
public void onAttach(Event value){
setCkValue(value);
}
});
public void setCkValue(String ckValue){
this.ckValue = ckValue;
}
public String getCkValue(){
return ckValue;
}

How to use GWT fileupload?

I have some queries when trying to implement a fileupload widget in my application. After many tries, it just doesn't seem to work.
Hence, I tried getting working solutions to see if I can understand anything from there.
http://code.google.com/p/faculty-gwt/source/checkout
However, I tried uploading a file using this and it seems that I am getting error messages too. and what is that textbox and listbox suppose to do? It is meant for showing an example of validating an input before submitting?
Can someone guide me along to solve this? Thanks.

Never tried to use the link you provided, but this is what i did to use a a GWT FileUpload widget:
I built a File Upload widget using the uibinder:
<g:FormPanel ui:field="docForm">
<g:FlowPanel ui:field="inputPane">
/*other displayed info*/
<g:FileUpload ui:field="DocPath"/>
/*other displayed info*/
</g:FlowPanel>
</g:FormPanel>
(Per the GWT api, FileUpload widgets can only be used from a FormPanel)
Make sure you set these in the FormPanel, otherwise you'll probably have issues:
yourFormPanel.setEncoding(FormPanel.ENCODING_MULTIPART);
yourFormPanel.setMethod(FormPanel.METHOD_POST);
That widget is dropped into my container page, then added to the display panel:
private FileUploadWidget createNewUploader(){
FileUploadWidget uploader = new FileUploadWidget(/*my constructor params*/);
uploader.addChangeHandler(new ChangeHandler() {
#Override
public void onChange(ChangeEvent event) {
DocPanel.add(createNewUploader());
}
});
return uploader;
}
My OnChange event is so that I have a new, blank uploader available when i use the current one.
and when I'm ready to submit:
private void processUpload(FileUploadWidget upload, int id) {
upload.setId(id);
//Don't bother to submit an empty one.
if (upload.IsFileSelected())
upload.Submit();
}

In GWT, how to reset the URL when the user hits "Cancel" in the navigation confirmation dialog?

In my GWT application, I want to ask a user confirmation when he navigates out of the current application, i.e. by entering a URL or closing the browser. This is typically done by registering a ClosingHandler and setting the desired dialog message in the onWindowClosing method. This seems to work well.
However, if the user tries to navigate say to http://www.gmail.com (by typing it in the URL bar) and hits Cancel to indicate he doesn't want to navigate, then my app keeps running but the browser's URL bar keeps indicating http://www.gmail.com. This causes a number of problems later in my application and will give the wrong result if the user bookmarks the page.
Is there a way to automatically reset the URL when the user presses Cancel?
Or, alternatively, is there a way to detect the user pressed the Cancel button? If so, is there a way to set the URL without triggering a ValueChangeEvent? (I could add some logic to prevent this, but I'd rather use a built-in mechanism if it exists.)

Not sure if this works but did you try: History.newItem(History.getToken(), false); to reset the URL? It does set the history token without triggering a new history item.

I managed to do this. It looks like GWT DeferredCommand are executed after the confirmation window has been closed. This, combined with Hilbrand's answer above, give me exactly what I want. Here is exactly what I do:
public final void onWindowClosing(Window.ClosingEvent event) {
event.setMessage(onLeaveQuestion);
DeferredCommand.addCommand( new Command() {
public void execute() {
Window.Location.replace(currentLocation);
}
});
}
Where currentLocation is obtained by calling Window.Location.getHref() every time the history token changes.

I solved this by creating a custom PlaceController and replacing the token in the url. Not an ideal solution but it works!
if (warning == null || Window.confirm(warning)) {
where = newPlace;
eventBus.fireEvent(new PlaceChangeEvent(newPlace));
currentToken = History.getToken();
} else {
// update the url when user clicks cancel in confirm popup.
History.replaceItem(currentToken, false);
}