[Xml-compile] adding xml:lang attribute

[Petar Shangov]

Hi Mark,

I still cannot get this to work properly. The value of $lang seems to get lost and is always undef during the 'after' hook. Admittedly, I am not very good with closures and such. Here is what I have tried:

# version 1
{ 
    my $lang;

    sub before_sub
    {  
        my ($doc, $values, $path) = @_;
        my %copy = %$values;
       $lang = delete $copy{'lang'}; 
       warn $lang;
       return \%copy;
    };

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

    $schema->addHook(
        path   => qr(tuv),
        before => \&before_sub,
        after  => \&after_sub,
    );    
}



# version 2
{ 
    my $lang;

    $schema->addHook(
        path   => qr(tuv),
        before => sub {  
           my ($doc, $values, $path) = @_;
           my %copy = %$values;
           $lang = delete $copy{'lang'}; 
           return \%copy;
        },
      after  => sub {  
           my ($doc, $node, $path) = @_;
           $node->setAttribute('xml:lang' => $lang);
           return $node;
        },
    );    
}

In both cases I get the xml:lang attribute where needed but its value is empty. I ended up using the following:

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

$schema->addHook(
  path   => qr'tuv$',
  after  => \&after_sub,
);

but it is only a temporary solution - it works because the 'tuv' element allows anyAttribute. And I will need xml:lang (and on several occasions xml:space) in serveral schemas I will be using, and with several different elements within each schema.

Second question: this is probably something I have not done properly, but I can't get the 'type' selector for adding hoods to work properly. Here is some of the options I tried (instead of 'path'):

type   => 'tuv'
type   => '{tmx}tuv' # 'tmx' is defined as a prefix
type   => '{http://www.lisa.org/tmx20}tuv'
type   => '{http://www.lisa.org/tmx20}tmx/body/tu/tuv'

and none triggers the hook (using the 'path' selector as specified above works OK).

Regards,

Petar



----- Original Message ----
> From: Mark Overmeer <mark at overmeer.net>
> To: Petar Shangov <pshangov at yahoo.com>
> Cc: xml-compile at lists.scsys.co.uk
> Sent: Saturday, 28 February, 2009 1:13:15
> Subject: Re: [Xml-compile] adding xml:lang attribute
> 
> * 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