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
/**
	 * Returns the value of the property in a localize format. Formats dates and
	 * numbers in the form according to the current locale. Converts choices and
	 * colors to their localized display names. Returns the localized display
	 * name for an element reference, etc.
	 * 
	 * @param module
	 *            the module
	 * @param propName
	 *            the property name
	 * @return the localized display value of the property
	 */
	public String getDisplayProperty( Module module, String propName )
	{
		PropertyDefn prop = getPropertyDefn( propName );
		if ( prop == null )
			return null;
		return getDisplayProperty( module, prop );
	}
	/**
	 * Returns the value of the property in a localize format. Formats dates and
	 * numbers in the form according to the current locale. Converts choices and
	 * colors to their localized display names. Returns the localized display
	 * name for an element reference, etc.
	 * 
	 * @param module
	 *            the module
	 * @param prop
	 *            the property definition
	 * @return the localized display value of the property