[Xml-compile] adding xml:lang attribute

[Mark Overmeer]

* Petar Shangov (pshangov at yahoo.com) [090227 16:18]:
> I need to add the xml:lang attribute to an element, but I can't
> seem to figure out how to do it.

There are a few spots where schema's are horrible, many to be
backwards compatible.  One is, for instance, the use of xsi:type.
Other spots are the attributes which start with xml, and the
"namespace" namespace.

And did you known that schema defines a clean "language" type (which
maps onto an xml:lang)?

The warnings you get are to be expected.  And probably, there should
be a clean way to hide a dirty "hook" trick.  This could be something
like:   (untested)

     use XML::Compile::Util qw/XMLNS/;
     $schema->new(...  , prefixes => [ xml => XMLNS ] );

     { my $lang;

       # avoid complaint about unused value for lang
       sub before($$$)
       {   my ($doc, $values, $path) = @_;
           my %copy = %$values;
           $lang = delete $copy{lang};  # or xml_lang?
           \%copy;
       }

       sub after($$$)
       {   my ($doc, $node, $path) = @_;
           $node->setAttribute('xml:lang' => $lang);
           $node;
       }

       $schema->addHook
         ( type   => \@types_with_xmllang
         , before => \&before
         , after  => \&after
         );
     }
       
See... it would be nice to have a predefined hook for this.
The other route would be to accept and xml:lang attribute everywhere, but
that would be extremely expensive.

This trick is described in XML::Compile::Translate::Writer, as a
general trick to work around bugs in schema's.
-- 
Regards,

               MarkOv

------------------------------------------------------------------------
       Mark Overmeer MSc                                MARKOV Solutions
       Mark at Overmeer.net                          solutions at overmeer.net
http://Mark.Overmeer.net                   http://solutions.overmeer.net