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/Module.java
*            the element to find
	 * @param propName
	 *            the property name to find
	 * @return the matched property binding defined in the module, otherwise
	 *         null
	 */
	public PropertyBinding findPropertyBinding( DesignElement element,
			String propName )
	{
		
		if ( element == null || propName == null )
			return null;
		
		
		if ( element.getPropertyDefn( propName ) == null )
			return null;
		
		
		List propertyBindings = getListProperty( this, PROPERTY_BINDINGS_PROP );
		if ( propertyBindings == null )
			return null;
		for ( int i = 0; i < propertyBindings.size( ); i++ )
		{
			PropertyBinding propBinding = (PropertyBinding) propertyBindings
					.get( i );
			BigDecimal id = propBinding.getID( );
			if ( id != null
					&& propName.equalsIgnoreCase( propBinding.getName( ) )
					&& getElementByID( id.longValue( ) ) == element )
				return propBinding;