Oh esteemed monks,

I have a problem where I need to pass a code reference to a custom SAX parser I wrote. The idea is to be able to swap out what is done by changing the callback function. I'm able to pass a callback to a package method, but not an object instance method. In this trivial example, it doesn't matter, but one of the functions I want to put in another callback involves databasing the information. I could put the database handler in a global, but that violates the concept of encapsulation.

MIS_SAX_Parser.pm

package MIS_SAX_Parser;
use Data::Dumper;
use XML::SAX::Base;
@ISA = ('XML::SAX::Base');
use strict;
use constant TYPE0 => 0;
use constant TYPE1 => 1;
use constant TYPE2 => 2;

sub new {
 my ($class, $callback) = @_;
 my $self  = { COUNTER => 0, HASHTYPE => TYPE0 };
 bless $self, $class;
 if ($callback) {
  $self->{CALLBACK} = \&$callback;
 } else {
  $self->{CALLBACK} = \&nocall;
 }
 return $self;
}

sub start_element {
 my ($self, $data) = @_;
 if ($data->{Name} eq "Column") {
  $self->{COLUMN_DATA}->{$data->{Attributes}->{"{}name"}->{Value}} = $
+data->{Attributes}->{"{}value"}->{Value};
 } elsif ($data->{Name} eq "Table") {
  $self->{TABLE_NAME} = $data->{Attributes}->{"{}name"}->{Value};
 }
}

sub end_element {
 my ($self, $data) = @_;
 my $name = $data->{Name};
 if ($name eq "Table") {
  $self->{CALLBACK}->($self->{TABLE_NAME}, $self->{COLUMN_DATA});
  # Reset the TABLE_NAME and COLUMN_DATA
  $self->{TABLE_NAME} = undef;
  $self->{COLUMN_DATA} = {};
 }
}

# Debug callback function
sub nocall {
 my ($table, $data) = @_;
 print "Table name is $table\n";
 print Dumper($data)."\n\n";
}

1;
[download]

MIS_PrintStatus.pm

package MIS_PrintStatus;
use Data::Dumper;
use strict;
use warnings;

sub new {
 my ($class) = @_;
 my $self = {};
 bless $self, $class;
 return $self;
}

sub printit {
 my ($table, $data) = @_;
 print "The table name is $table\n";
}

1;
[download]

MISParse.pl

#!/usr/bin/perl
use XML::LibXML;
use XML::LibXML::SAX::Parser;
use MIS_SAX_Parser;
use MIS_PrintStatus;
use strict;

my $filename = shift @ARGV;
my $cb = MIS_PrintStatus->new();

my $parser = XML::LibXML->new;
my $doc = $parser->parse_file($filename);
my $handler = MIS_SAX_Parser->new(\&MIS_PrintStatus::printit);
my $generator = XML::LibXML::SAX::Parser->new(Handler => $handler);
$generator->generate($doc);
[download]

Now what I'd like to do is be able to pass a reference to $cb->printit to the MIS_SAX_Parser object. Anyone know the syntax for this? I tried what I thought were all the usual suspects and only got errors. Thanks.

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