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How to register a listener to datachange on Form or Page [message #1842323]

Wed, 16 June 2021 13:37

Seydou Zakou

Messages: 44
Registered: May 2020

Member

Hi all,

I have a form with a table field inside And I need to know when the data in the TableField is dirty [modified from some where (another Form) in the application ] to notify the user when he come back to the form so he could reopen/reload the form.
Try to follow indication at this thread https://www.eclipse.org/forums/index.php/t/1100146/ but don't know where to start.

Does anyone has an idea ?

Thank you.

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Re: How to register a listener to datachange on Form or Page [message #1842335 is a reply to message #1842323]

Wed, 16 June 2021 16:41

Mr Robot

Messages: 72
Registered: March 2020

Member

Hello,

you could use Client Notifications.

Check this:
https://eclipsescout.github.io/10.0/technical-guide.html#client-notifications.

So when form is stored in service you create notification, on client side you have listener to reload form when notification is sent

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Re: How to register a listener to datachange on Form or Page [message #1842347 is a reply to message #1842335]

Wed, 16 June 2021 19:53

Seydou Zakou

Messages: 44
Registered: May 2020

Member

Thanks for your reply.

But if I can listen for change directly from Form or Page, since I saw that AbstractForm and AbstractPage already register for change listeners, it will be simpler than implementing the client notification system, that also lack sample use case.

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Re: How to register a listener to datachange on Form or Page [message #1842363 is a reply to message #1842347]

Thu, 17 June 2021 07:35

Claudio Guglielmo

Messages: 259
Registered: March 2010

Senior Member

Hi,

to check, whether a table is dirty, you can use the method isSaveNeeded of ITableField.
If you want to listen for changes, you can add a table listener to the table using ITable.addTableListener. You are probably interested in TableEvent.TYPE_ROWS_INSERTED, TableEvent.TYPE_ROWS_UPDATED, TableEvent.TYPE_ROWS_DELETED.

If you need to be notified when a form is closed, add a form listener to the form using IForm.addFormListener with the type FormEvent.TYPE_CLOSED. With the IForm.getCloseSystemType() you can determine whether the user pressed Ok or Cancel, or just use IForm.isFormStored().

If you want, you can then trigger a DataChangeEvent, as described in the linked post, to inform other widgets that your data changed, but I don't think this is necessary for your use case.

If you want to get informed when another user changes the data displayed on your form, then you should use client notifications.

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Re: How to register a listener to datachange on Form or Page [message #1842371 is a reply to message #1842363]

Thu, 17 June 2021 09:59

Seydou Zakou

Messages: 44
Registered: May 2020

Member

Thank you for your reponse.

If I understand, {ITable, IForm} listeners respond to event on client side, I can't fire these events from server side.
I just tried the client notification as below:
- Shared module

public class NotificationMessage implements serializable {
  private static final long serialVersionUID = -913943548821914510L; 
  private String message;
  // setters/getters/ctors
}

- Server side

NotificationMessage msg = new NotificationMessage("..");
BEANS.get(ClientNotificationRegistry.class).putForAllSessions(msg);

- Client Side

public class MessageNotificationHandler implements INotificationHandler<NotificationMessage> {
	@Override
	public void handleNotification(NotificationMessage notification) {
		ModelJobs.schedule(() -> {
			if (Desktop.CURRENT.get() != null) {
				Desktop.CURRENT.get().addNotification(new DesktopNotification("Notification Got: Message = " + notification.getMessage()));
			}
		}, ModelJobs.newInput(ClientRunContexts.copyCurrent()));
	}
}

My problem now is that I don't know how to attach this handler only on some specific Page or Form, so I can access the widget on it.

Thank you.

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Re: How to register a listener to datachange on Form or Page [message #1842383 is a reply to message #1842371]

Thu, 17 June 2021 12:40

Mr Robot

Messages: 72
Registered: March 2020

Member

On you handleNotification method, you can check for active form/page.

For example:

if(Desktop.CURRENT.get().getOutline().getActivePage() instanceof SomeActivePage.class) {
       Desktop.CURRENT.get().getOutline().getActivePage().reloadPage();
}

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