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
extendsRef = new ElementRefValue( namespace, base );
			base.addDerived( this );
		}
	}
	/**
	 * Returns the data set element, if any, for this element.
	 * 
	 * @param module
	 *            the module of this element
	 * 
	 * @return the data set element defined on this specific element
	 */
	public TemplateParameterDefinition getTemplateParameterElement(
			Module module )
	{
		ElementRefValue templateParam = (ElementRefValue) getProperty( module,
				REF_TEMPLATE_PARAMETER_PROP );
		if ( templateParam == null )
			return null;
		return (TemplateParameterDefinition) templateParam.getElement( );
	}
	/**
	 * Returns a list of the descendents of this element. The descendents
	 * include elements that directly extend from this one, along with elements
	 * that extend from those, and so on recursively.
	 * <p>
	 * Part of: Inheritance system.
	 * 
	 * @return The list of descendents.
	 */