//IF IT'S A LEAF (FROM VIEW) BEING DROPPED ON ROOT NODE LEVEL
if (!dropNode && targetNode.getDepth() == 1 && (pt == "above" || pt == "below"))
    return false;
if (dropNode) {
    //IF IT'S A FOLDER BEING DROPPED ON A FOLDER
    if(targetNode.allowNonLeafChildren === false && dropNode.isLeaf() == false && pt == "append")
    	return false;
    //IF IT'S A FOLDER BEING DROPPED ONTO A LEAF
    if (dropNode.isLeaf() == false && targetNode.isLeaf() == true)
    	return false;
    //IF IT'S A LEAF BEING DROPPED ON ROOT NODE LEVEL
    if (dropNode.isLeaf() == true && targetNode.getDepth() == 1 && (pt == "above" || pt == "below"))
    	return false;
}