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
* @param prop
	 *            the definition of property
	 * @return the property value, or null if no value is set.
	 */
	protected Object getPropertyFromSlotSelector( Module module,
			ElementPropertyDefn prop )
	{
		if ( getContainer( ) == null )
			return null;
		String selector = getContainer( ).getSelector( getContainerSlot( ) );
		return getPropertyFromSelector( module, prop, selector );
	}
	/**
	 * Returns the property value which is related to container.
	 * 
	 * @param module
	 *            the module
	 * @param prop
	 *            the definition of property
	 * @return the property value, or null if no value is set.
	 */
	protected Object getPropertyRelatedToContainer( Module module,
			ElementPropertyDefn prop )
	{
		return null;
	}
	/**
	 * Returns the property value.
	 * 
	 * @param module