Class mxClipboard

mxClipboard.copy(graph);
mxClipboard.paste(graph2);

This copies the selection cells from the graph to the clipboard and pastes them into graph2.

For fine-grained control of the clipboard data the mxGraph.canExportCell and mxGraph.canImportCell functions can be overridden.

To restore previous parents for pasted cells, the implementation for copy and paste can be changed as follows.

mxClipboard.copy = function(graph, cells)
{
  cells = cells || graph.getSelectionCells();
  var result = graph.getExportableCells(cells);

  mxClipboard.parents = new Object();

  for (var i = 0; i < result.length; i++)
  {
    mxClipboard.parents[i] = graph.model.getParent(cells[i]);
  }

  mxClipboard.insertCount = 1;
  mxClipboard.setCells(graph.cloneCells(result));

  return result;
};

mxClipboard.paste = function(graph)
{
  if (!mxClipboard.isEmpty())
  {
    var cells = graph.getImportableCells(mxClipboard.getCells());
    var delta = mxClipboard.insertCount * mxClipboard.STEPSIZE;
    var parent = graph.getDefaultParent();

    graph.model.beginUpdate();
    try
    {
      for (var i = 0; i < cells.length; i++)
      {
        var tmp = (mxClipboard.parents != null && graph.model.contains(mxClipboard.parents[i])) ?
             mxClipboard.parents[i] : parent;
        cells[i] = graph.importCells([cells[i]], delta, delta, tmp)[0];
      }
    }
    finally
    {
      graph.model.endUpdate();
    }

    // Increments the counter and selects the inserted cells
    mxClipboard.insertCount++;
    graph.setSelectionCells(cells);
  }
};