Bug 121352 The data set binding property cannot be retrieved in report preview layout
In report preview page, the datasource/dataset property binding lists cannot be retrieved. The dataset binding can not work correctly in layout preview because it's value cannot get from the binding list. But in the data set edit page, the binding value can be got. You can refer to the attachment.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
* Gets the value of a property as a list.
	 * 
	 * @param module
	 *            the module
	 * @param propName
	 *            the name of the property to get
	 * @return the value as an <code>ArrayList</code>, or null if the
	 *         property is not set or the value is not a list
	 */
	public List getListProperty( Module module, String propName )
	{
		Object value = getProperty( module, propName );
		if ( value == null )
			return null;
		if ( value instanceof ArrayList )
			return (ArrayList) value;
		return null;
	}
	/**
	 * Gets the set of property definitions available to this element. Includes
	 * all properties defined for this element, all user-defined properties
	 * defined on this element or its ancestors, and any style properties that
	 * this element supports.
	 * 
	 * @return a list of property definitions
	 */
	public List getPropertyDefns( )
	{
		List list = getDefn( ).getProperties( );
		DesignElement e = this;