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 DesignElement getExtendsElement( )
	{
		if ( extendsRef == null )
			return null;
		return extendsRef.getElement( );
	}
	/**
	 * Gets the name of the element that this element extends.
	 * 
	 * @return The name of the extended element.
	 */
	public String getExtendsName( )
	{
		if ( extendsRef == null )
			return null;
		return StringUtil.buildQualifiedReference( extendsRef
				.getLibraryNamespace( ), extendsRef.getName( ) );
	}
	/**
	 * Returns the optional element name.
	 * <p>
	 * Part of: The name system.
	 * 
	 * @return Returns the name.
	 */
	public String getName( )
	{
		return name;
	}
	/**