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
StyleElement style = module.findStyle( selector );
		if ( style != null )
		{
			return style.getLocalProperty( module, prop );
		}
		return null;
	}
	/**
	 * Returns the property value which is related to element selector. It is
	 * from the selector style.
	 * 
	 * @param module
	 *            the module
	 * @param prop
	 *            the definition of property
	 * @return the property value, or null if no value is set.
	 */
	protected Object getPropertyFromSelfSelector( Module module,
			ElementPropertyDefn prop )
	{
		String selector = ( (ElementDefn) getDefn( ) ).getSelector( );
		return getPropertyFromSelector( module, prop, selector );
	}
	/**
	 * Returns the property value which is related to slot selector. It is from
	 * the selector style which represents the slot or combination of container
	 * and slot.
	 * 
	 * @param module
	 *            the module