Drag N Drop

Classic Servoy
1

Hi

I am having an issue making drag n drop work which is now getting critical for a client demo next week. Having not used this in the past I downloaded the example from the Servoy SVN and tested solution items 1-4 work perfectly, however the key element I need is to be able to drag files from the users file system onto Servoy, record the file name and trigger a streaming upload to the server. I have tried the DNDFileBean from I think Servoy Forge, however it would appear certainly in later versions of Servoy this is not necessary.

On the basis the SVN demo file failed I decided to build a super basic form with a single Label called Test

  1. I have enabled the drag and drop with the following on the form
  2. I have a label named Test (incidentally i also tried it with a field and variables called Test)
  3. I have a Drag Over script enabled as follows
function onDragOver(event) {
	application.output(event)
	if (event.getElementName() == 'Test' && event.data) 
	{
		application.output('dragged over')
		return true;
	}	
	return false;
}
  1. and I have a drop script
function onDrop(event) {
	// TODO Auto-generated method stub
	application.output('dropped')
	return false
}

The questions are:

a) Should this at least trigger the fact that item was dragged over i.e. output something from the event
b) Am I barking up the wrong tree all together
c) Does anyone have a working example because the Servoy version does not seem to work in example 5

I have tried this in both Servoy 6 final and 5.2.9

Many thanks in anticipation !

Gordon

2

It is a bit tricky.

In Servoy 6 dropping files is supported, in Servoy 5 you need the bean.

The problem is the event.data that you receive. It is a native type: java.util.List<java.io.File>, meaning basically it is a list of files.

Look at these two methods:

function onDragOver(event) {
	if (event.getSource() && event.data) {
		if (event.data instanceof java.util.List && event.data.size() > 0 && event.data.get(0) instanceof java.io.File) {
			//event.data contains a List of files
			return true;
		}
	}
        // only files allowed in this example
	return false;
}

and

function onDrop(event) {
	if (event.getSource() && event.data) {
		if (event.data instanceof java.util.List && event.data.size() > 0 && event.data.get(0) instanceof java.io.File) {
			// we have a List of items
			for (var i = 0; i < event.data.size(); i++) {
				var vJsFile = plugins.file.convertToJSFile(event.data.get(i).getAbsolutePath());
				application.output(vJsFile.getAbsolutePath());				
			}
			return true;
		}
	}
	return false;
}

Note that a List is not an array. To see what you can do with a List, check this http://download.oracle.com/javase/6/doc … /List.html. Basically, I think you will need only List.size() and List.get(index) where Lists are zero based.

Hope this helps.

3

Thanks Patrick - that makes sense and would explain why the demo failed as I think its about 12-14 months old.

I think Servoy need to consider setting up a group of developers who could update the various demos for each iteration, or at least test that the features contained are using the current technology rather than depreciated older version.

Cheers
Gordon