# $Id: Record.pm,v 1.28 2007-12-12 08:49:58 mike Exp $
package ZOOM::IRSpy::Record;
### I don't think there's any reason for this to be separate from
# ZOOM::IRSpy::Connection, now that the correspondence is always 1:1
use 5.008;
use strict;
use warnings;
use XML::LibXML;
use XML::LibXML::XPathContext;
use ZOOM::IRSpy::Utils qw(xml_encode isodate irspy_xpath_context);
=head1 NAME
ZOOM::IRSpy::Record - record describing a target for IRSpy
=head1 SYNOPSIS
## To follow
=head1 DESCRIPTION
I<## To follow>
=cut
sub new {
my $class = shift();
my($irspy, $target, $zeerex) = @_;
if (!defined $zeerex) {
$zeerex = _empty_zeerex_record($target);
}
### Parser should be in the IRSpy object
my $parser = new XML::LibXML();
return bless {
irspy => $irspy,
target => $target,
parser => $parser,
zeerex => $parser->parse_string($zeerex)->documentElement(),
}, $class;
}
sub _empty_zeerex_record {
my($target) = @_;
my($protocol, $host, $port, $db) =
ZOOM::IRSpy::_parse_target_string($target);
my $xprotocol = xml_encode($protocol);
my $xhost = xml_encode($host);
my $xport = xml_encode($port);
my $xdb = xml_encode($db);
return <<__EOT__;
$xhost
$xport
$xdb
__EOT__
}
sub append_entry {
my $this = shift();
my($xpath, $frag) = @_;
#print STDERR "this=$this, xpath='$xpath', frag='$frag'\n";
my $xc = $this->xpath_context();
$xc->registerNs(zeerex => "http://explain.z3950.org/dtd/2.0/");
$xc->registerNs(irspy => $ZOOM::IRSpy::Utils::IRSPY_NS);
my @nodes = $xc->findnodes($xpath);
if (@nodes == 0) {
# Make the node that we're inserting into, if possible. A
# fully general version would work its way through each
# component of the XPath, but for now we just treat it as a
# single chunk to go inside the top-level node.
$this->_half_decent_appendWellBalancedChunk($xc->getContextNode(),
"<$xpath>$xpath>");
@nodes = $xc->findnodes($xpath);
die("still no matches for '$xpath' after creating: can't append")
if @nodes == 0;
}
$this->{irspy}->log("warn",
scalar(@nodes), " matches for '$xpath': using first")
if @nodes > 1;
$this->_half_decent_appendWellBalancedChunk($nodes[0], $frag);
}
sub xpath_context {
my $this = shift();
return irspy_xpath_context($this->{zeerex});
}
sub store_result {
my ($this, $type, %info) = @_;
my $xml = "\n";
$this->append_entry('irspy:status', $xml);
}
# *sigh*
#
# _Clearly_ the right way to append a well-balanced chunk of XML to
# a node's children is to call appendWellBalancedChunk() from the
# XML::LibXML::Element class. However, this fails in the common case
# where the ZeeRex record we're working with doesn't declare the
# "irspy" namespace that the inserted fragments use.
#
# To my utter astonishment it seems that XML::LibXML (as of version
# 1.58, 31st March 2004) doesn't provide ANY way to register a
# namespace for parsing, which makes the parse_balanced_chunk()
# function that appendWellBalancedChunk() uses effectively useless.
# It _is_ possible to use setNamespace() on a node, to register a new
# namespace mapping for that node -- but that only affects pre-parsed
# trees, and is no use for parsing. Hence the following pair of lines
# DOES NOT WORK:
# $node->setNamespace($ZOOM::IRSpy::Utils::IRSPY_NS, "irspy", 0);
# $node->appendWellBalancedChunk($frag);
#
# Instead I have to go the long way round, hence this method. I have
# two candidate re-implementations, of which the former is marginally
# less loathsome, but does require that the excess namespace
# declarations be factored out later -- as least, if you want neat
# output.
#
sub _half_decent_appendWellBalancedChunk {
my $this = shift();
my($node, $frag) = @_;
if (1) {
$frag =~ s,>, xmlns:irspy="$ZOOM::IRSpy::Utils::IRSPY_NS">,;
eval {
$node->appendWellBalancedChunk($frag);
}; if ($@) {
print STDERR "died while trying to appendWellBalancedChunk(), probably due to bad XML:\n$frag";
die $@;
}
return;
}
# Instead -- and to call this brain-damaged would be an insult
# to all those fine people out there with actual brain damage
# -- I have to "parse" the XML fragment myself and insert the
# resulting hand-build DOM tree. Someone shoot me now.
my($open, $content, $close) = $frag =~ /^<(.*?)>(.*)<\/(.*?)>$/;
die "can't 'parse' XML fragment '$frag'"
if !defined $open;
my($tag, $attrs) = $open =~ /(.*?)\s(.*)/;
$tag = $open if !defined $tag;
die "mismatched XML start/end <$open>...<$close>"
if $close ne $tag;
print STDERR "tag='$tag', attrs=[$attrs], content='$content'\n";
die "## no code yet to make DOM node";
}
=head1 SEE ALSO
ZOOM::IRSpy
=head1 AUTHOR
Mike Taylor, Emike@indexdata.comE
=head1 COPYRIGHT AND LICENSE
Copyright (C) 2006 by Index Data ApS.
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself, either Perl version 5.8.7 or,
at your option, any later version of Perl 5 you may have available.
=cut
1;