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
if ( ref.isResolved( ) )
			ref.getTargetElement( ).addClient( this, prop.getName( ) );
		return ref;
	}
	/**
	 * Resolves a property structure reference. The reference is the value of a
	 * property of type property structure reference.
	 * 
	 * @param module
	 *            the module information needed for the check, and records any
	 *            errors
	 * @param prop
	 *            the property whose type is structure reference
	 * @return the resolved value if the resolve operation is successful,
	 *         otherwise the unresolved value
	 */
	public StructRefValue resolveStructReference( Module module,
			ElementPropertyDefn prop )
	{
		Object value = propValues.get( prop.getName( ) );
		assert value == null || value instanceof StructRefValue;
		if ( value == null || module == null )
			return (StructRefValue) value;
		StructRefValue ref = (StructRefValue) value;
		if ( ref.isResolved( ) )
			return ref;