[xsd-users] Keep a xsd library small

[Boris Kolpackov]

Hi Angelo,

Angelo Difino <angelo at cedeo.net> writes:

> Hi Boris and all,
> I still keep working hard on the xsd-types of the schemes i've sent you 
> on the 12nd of February.
> 
> I've some troubles since in the first release i forgot (me damn it! ;) ) 
> to include the specifier "--generate-wildcard"
> since i've several tags include the any-type. for example the DIDL.xsd 
> include an any tag for the structured data
> type:
> 
> didl.xsd -> StatementType ->  <element ref="didl-msx:Metadata"/>
> didl-msx -> MetadataType -> StructuredDataType ->
>        <sequence>
>            <any namespace="##any" processContents="lax" minOccurs="0"/>
>        </sequence>
> 
> when i need to simply assign (clone) an ItemType (that include the above 
> structured data type)
> i've a run-time xerces error on the wildcard-source.txx:
> 
>          // Get an implementation of the Load-Store (LS) interface.
>          //
>          xercesc::DOMImplementation* impl (
>            xercesc::DOMImplementationRegistry::getDOMImplementation (ls));
> 
>          return xml::dom::auto_ptr<xercesc::DOMDocument> (
>            impl->createDocument ());
> 
> Am I missing somethins ? I'm checking your documentation but i really 
> wondering if now (that i've added the
> "--generate-wildcard"), i need to implement / wrote some code some where 
> to "help" xerces when it founds an any type...

You need to initialize the Xerces-C++ runtime. From Section 2.12, "Mapping
for any and anyAttribute" in the C++/Tree Mapping User Manual:

"For the XML Schema any and anyAttribute wildcards an optional mapping 
 can be requested with the --generate-wildcard option. The mapping 
 represents the content matched by wildcards as DOM fragments. Because
 the DOM API is used to access such content, the Xerces-C++ runtime
 should be initialized by the application prior to parsing and should
 remain initialized for the lifetime of objects with the wildcard
 content. For more information on the Xerces-C++ runtime initialization
 see Section 3.1, "Initializing the Xerces-C++ Runtime"."


> The code that throw the error is:
> 
> std::auto_ptr< DIDLType > tmp = DIDL(filename.c_str() , (validate ? 0 : 
> xml_schema::flags::dont_validate) );
> mxm_dataobject::schema::didl::ItemType& topelement = 
> dynamic_cast<mxm_dataobject::schema::didl::ItemType&>(_didl->Item());
> mxm_dataobject::schema::didl::ItemType secondelement=topelement;    (in 
> a inner class)

The above code should be something along these lines:

#include <xercesc/util/PlatformUtils.hpp>

int
main ()
{
  xercesc::XMLPlatformUtils::Initialize ();

  {
    std::auto_ptr< DIDLType > tmp = DIDL(filename.c_str(), (validate ? 0 : 
      xml_schema::flags::dont_validate | xml_schema::flags::dont_initialize) );

    mxm_dataobject::schema::didl::ItemType& topelement = 
      dynamic_cast<mxm_dataobject::schema::didl::ItemType&>(_didl->Item());

    mxm_dataobject::schema::didl::ItemType secondelement=topelement;
  }

  xercesc::XMLPlatformUtils::Terminate ();
}

Notice that I've added the dont_initialize flag to the parsing function
call.

Boris