gistfile1.txt

var clipboardKey = '.drawio-clipboard';

mxClipboard.isEmpty = function()
{
	return localStorage.getItem(clipboardKey) == null;
};

mxClipboard.setCells = function(cells)
{
	var codec = new mxCodec();
	var model = new mxGraphModel();
	var parent = model.getChildAt(model.getRoot(), 0);
	
	for (var i = 0; i < cells.length; i++)
	{
		model.add(parent, cells[i]);
	}

	localStorage.setItem(clipboardKey, mxUtils.getXml(codec.encode(model)));
};

mxClipboard.getCells = function()
{
	var xml = localStorage.getItem(clipboardKey);
	var doc = mxUtils.parseXml(xml);
	var codec = new mxCodec(doc);
	var model = codec.decode(doc.documentElement);
	var parent = model.getChildAt(model.getRoot(), 0);
	var childCount = model.getChildCount(parent);
	var cells = [];
	
	for (var i = 0; i < childCount; i++)
	{
		cells.push(model.getChildAt(parent, i));
	}
	
	return cells;
};