"teddysnips@hotmail.com" wrote:

> <NEWBIE ALERT>
>
> Owing to staff lossage, I've been forced to take over maintenance and
> upgrade of a completely undocumented web service (VS 2003, VB.NET).
>
> I've been asked to amend a Public Function and, being a lazy sort,
> thought about using Optional parameters.
>
> However, I noticed something weird about the Function that was built in
> the Proxy class:
>
> VB
> ==
>
> <WebMethod(), SoapHeader("Credentials"), SoapHeader("ResultHeader",
> Direction:=SoapHeaderDirection.Out)> _
> Public Function CreateGroupBooking(ByVal key As IndividualKey, ByVal
> groupName As String, _
> ByVal email As String, ByVal address As Address, ByVal
> contactFirstName As String, _
> ByVal contactLastName As String) As BookingList
>
> PROXY
> ======
>
> Public Function CreateGroupBooking(ByVal key As IndividualKey, ByVal
> groupName As String, ByVal email As String,
> <System.Xml.Serialization.XmlElementAttribute(IsNullable:=true)> ByVal
> Address As Address, ByVal contactFirstName As String, ByVal
> contactLastName As String) As
> <System.Xml.Serialization.XmlElementAttribute("BookingList",
> IsNullable:=true)> BookingList
>
>
> I can't quite figure out what's with the
>
> <System.Xml.Serialization.XmlElementAttribute(IsNullable:=true)>
>
> that prefixes the Address parameter and the BookingList return.
>
> I note that the class declaration for the BookingList, for example is:
>
> <XmlRoot(ElementName:="BookingList")> _
> Public Class BookingList
>
> If I remove the line
>
> <XmlRoot(ElementName:="BookingList")> _
>
> the tag is not there! The same goes for the Address class.
>
> Is this some kind of kludge to allow nullable parameters? Remember, I
> am a newbie!
>
> Thanks
>
> Edward
>