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
public IObjectDefn getObjectDefn( )
	{
		return getDefn( );
	}
	/**
	 * Returns the value of an element reference property as an element. Returns
	 * null if either the property is unset, or the reference is unresolved.
	 * 
	 * @param module
	 *            the module
	 * @param propName
	 *            the name of the element reference property to get
	 * @return the element referenced by the property
	 */
	public DesignElement getReferenceProperty( Module module, String propName )
	{
		ElementRefValue ref = (ElementRefValue) getProperty( module, propName );
		if ( ref == null )
			return null;
		return ref.getElement( );
	}
	/**
	 * Returns whether this element has references. That is, whether any other
	 * elements reference this one using an element reference property. This
	 * query does not check for "extends" references.
	 * 
	 * @return whether other elements refer to this one
	 */
	public boolean hasReferences( )
	{