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 String getDisplayProperty( Module module, PropertyDefn prop )
	{
		Object value = getProperty( module, prop );
		if ( value == null )
			return null;
		return prop.getDisplayValue( module, value );
	}
	/**
	 * Sets an unresolved extends name. The resolved relationships is not
	 * cached; it must be resolved later.
	 * 
	 * @param name
	 *            the name of the new parent element, or null if this element
	 *            does not extend any other element
	 */
	public void setExtendsName( String name )
	{
		setExtendsElement( null );
		name = StringUtil.trimString( name );
		if ( name == null )
			return;
		String namespace = StringUtil.extractNamespace( name );
		name = StringUtil.extractName( name );
		extendsRef = new ElementRefValue( namespace, name );
	}
	/**
	 * Validates this element and its contents.
	 * 
	 * @param module