XML::Filter::SAXT - Replicates SAX events to several SAX event handlers
$saxt = new XML::Filter::SAXT ( { Handler => $out1 },
{ DocumentHandler => $out2 },
{ DTDHandler => $out3,
Handler => $out4
}
);
$perlsax = new XML::Parser::PerlSAX ( Handler => $saxt ); $perlsax->parse ( [OPTIONS] );
SAXT is like the Unix 'tee' command in that it multiplexes the input stream to several output streams. In this case, the input stream is a PerlSAX event producer (like XML::Parser::PerlSAX) and the output streams are PerlSAX handlers or filters.
The SAXT constructor takes a list of hash references. Each hash specifies an output handler. The hash keys can be: DocumentHandler, DTDHandler, EntityResolver or Handler, where Handler is a combination of the previous three and acts as the default handler. E.g. if DocumentHandler is not specified, it will try to use Handler.
In this example we use XML::Parser::PerlSAX to parse an XML file and to invoke the PerlSAX callbacks of our SAXT object. The SAXT object then forwards the callbacks to XML::Checker, which will 'die' if it encounters an error, and to XML::Hqandler::BuildDOM, which will store the XML in an XML::DOM::Document.
use XML::Parser::PerlSAX; use XML::Filter::SAXT; use XML::Handler::BuildDOM; use XML::Checker;
my $checker = new XML::Checker;
my $builder = new XML::Handler::BuildDOM (KeepCDATA => 1);
my $tee = new XML::Filter::SAXT ( { Handler => $checker },
{ Handler => $builder } );
my $parser = new XML::Parser::PerlSAX (Handler => $tee);
eval
{
# This is how you set the error handler for XML::Checker
local $XML::Checker::FAIL = \&my_fail;
my $dom_document = $parser->parsefile ("file.xml");
... your code here ...
};
if ($@)
{
# Either XML::Parser::PerlSAX threw an exception (bad XML)
# or XML::Checker found an error and my_fail died.
... your error handling code here ...
}
# XML::Checker error handler
sub my_fail
{
my $code = shift;
die XML::Checker::error_string ($code, @_)
if $code < 200; # warnings and info messages are >= 200
}
This is still alpha software. Package names and interfaces are subject to change.
Send bug reports, hints, tips, suggestions to Enno Derksen at <enno@att.com>.