SQL User Defined Types may define methods. In context of Virtuoso SOAP server they can be exposed as SOAP methods. To do that the UDT must be published at an endpoint. So publishing could be done in two ways: using SQL INSERT statement or using Admin UI: Publishing UI via Virtual directories section.

The published UDTs will then expose all methods to the given virtual directory assigned for SOAP execution. In this case the default constructor will be called for method invocation if the UDT method is non-static.

Note: The method definitions may also contains special SOAP syntax for XML Schema datatypes, using the same options as for PL procedures. (see "PL Procedures and UDT Methods Syntax Affecting WSDL & SOAP Processing" section for details)

The following table specifies which UDTs are published at which end points.

create table SYS_SOAP_UDT_PUB
            (SUP_CLASS varchar, -- name of the published UDT, referencing SYS_USER_TYPES.UT_NAME
             SUP_LHOST varchar, -- listen host, referencing HTTP_PATH.HP_LISTEN_HOST
             SUP_HOST varchar,  -- virtual host, referencing HTTP_PATH.HP_HOST
             SUP_END_POINT varchar, -- logical path, referencing HTTP_PATH.HP_LPATH
             primary key (SUP_LHOST, SUP_HOST, SUP_END_POINT, SUP_CLASS))
;
            

create user SOAP_U2;

VHOST_DEFINE (lpath=>'/soap-udt', ppath=>'/SOAP/', soap_user=>'SOAP_U2',
    soap_opts=>
    vector ('ServiceName', 'UDT',
            'Namespace', 'http://temp.uri',
            'SchemaNS', 'http://temp.uri',
            'MethodInSoapAction', 'yes',
            'elementFormDefault', 'unqualified',
            'Use', 'encoded')
);

create type MyWebSvc
static method echoStatInt (in a int) returns int,
method echoInt (in a int) returns int;

create static method echoStatInt (in a int)
returns int for MyWebSvc
{
  return a;
}
;

create method echoInt (in a int)
returns int for MyWebSvc
{
  return a;
}
;

-- Important: without grant publishing is not final as
-- user for SOAP invocation will not have permissions to instantiate the UDT nor
-- to call its methods
grant execute on MyWebSvc to SOAP_U2;

-- exposing the UDT methods to the /soap-udt endpoint
insert soft SYS_SOAP_UDT_PUB values ('MyWebSvc', '*ini*', '*ini*', '/soap-udt');

Exposing the methods of a UDT could be done using Admin UI/Virtual Directories: Create a new or edit an existing SOAP enabled virtual directory and navigate to the SOAP options section, click on the 'Publish' button and from presented list of Database qualifiers select the qualifier containing target UDT, then select it from the User Defined Types list and follow the wizard.