-# $Id: Record.pm,v 1.6 2006-07-21 16:50:20 mike Exp $
+# $Id: Record.pm,v 1.10 2006-07-25 16:53:28 mike Exp $
package ZOOM::IRSpy::Record;
my $parser = new XML::LibXML();
return bless {
target => $target,
+ parser => $parser,
zeerex => $parser->parse_string($zeerex)->documentElement(),
}, $class;
}
my $this = shift();
my($xpath, $frag) = @_;
- print STDERR "this=$this, xpath='$xpath', frag='$frag'\n";
+ #print STDERR "this=$this, xpath='$xpath', frag='$frag'\n";
my $root = $this->{zeerex}; # XML::LibXML::Element ISA XML::LibXML::Node
- print "Record='", $root->toString(), "'\n";
my $xc = XML::LibXML::XPathContext->new($root);
$xc->registerNs(zeerex => "http://explain.z3950.org/dtd/2.0/");
$xc->registerNs(irspy => "http://indexdata.com/irspy/1.0");
my @nodes = $xc->findnodes($xpath);
if (@nodes == 0) {
- ZOOM::Log::log("irspy", "no matches for '$xpath': can't append");
+ # 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.
+ $this->_half_decent_appendWellBalancedChunk($root,
+ "<$xpath></$xpath>");
+ @nodes = $xc->findnodes($xpath);
+ die("still no matches for '$xpath' after creating: can't append")
+ if @nodes == 0;
+ }
+
+ ZOOM::Log::log("irspy",
+ scalar(@nodes), " matches for '$xpath': using first")
+ if @nodes > 1;
+
+ $this->_half_decent_appendWellBalancedChunk($nodes[0], $frag);
+}
+
+
+# *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("http://indexdata.com/irspy/1.0", "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="http://indexdata.com/irspy/1.0">,;
+ $node->appendWellBalancedChunk($frag);
return;
- } elsif (@nodes > 1) {
- ZOOM::Log::log("irspy", scalar(@nodes),
- " matches for '$xpath': using first");
}
- print STDERR "zeerex='$root'\n";
+ # 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";
}