Bug 122869 Drag a parameter from data explorer view into a table in library, a new parameter is created automatically.
Description:Drag a parameter from data explorer view into a table in library, a new parameter is created automatically. Steps to reproduce: 1. Add a cascading parameter and a table in a library file. 2. Drag a parameter from data explorer view into a table cell in layout editor. 3. Find that a new parameter was added in data explorer view automatically.
UI/org.eclipse.birt.report.designer.core/src/org/eclipse/birt/report/designer/util/DEUtil.java
* @param basePath
	 *            the base path
	 * @param path
	 *            the path to convert
	 * @return The relative path based on the base path if it is possible, or
	 *         the original path
	 * 
	 */
	public static String getRelativedPath( String basePath, String path )
	{
		return URIUtil.getRelativePath( new File( basePath ).getParent( ), path );
	}
	/**
	 * Returns the handle of the action of the given element.
	 * 
	 * @param element
	 *            the element handle
	 * @return the handle of the action, or null if the element is not a proper
	 *         type
	 */
	public static ActionHandle getActionHandle( ReportItemHandle element )
	{
		ActionHandle actionHandle = null;
		if ( element instanceof LabelHandle )
		{
			actionHandle = ( (LabelHandle) element ).getActionHandle( );
		}
		else if ( element instanceof DataItemHandle )
		{
			actionHandle = ( (DataItemHandle) element ).getActionHandle( );