-# $Id: Utils.pm,v 1.1 2006-10-30 15:02:06 mike Exp $
+# $Id: Utils.pm,v 1.9 2006-11-09 16:09:35 mike Exp $
package ZOOM::IRSpy::Utils;
use strict;
use warnings;
-sub x { return 1 }
+use Exporter 'import';
+our @EXPORT_OK = qw(xml_encode
+ irspy_xpath_context
+ modify_xml_document
+ inheritance_tree);
+
+use XML::LibXML;
+use XML::LibXML::XPathContext;
+
+our $IRSPY_NS = 'http://indexdata.com/irspy/1.0';
+
+
+# Utility functions follow, exported for use of web UI
+
+# I can't -- just can't, can't, can't -- believe that this function
+# isn't provided by one of the core XML modules. But the evidence all
+# says that it's not: among other things, XML::Generator and
+# Template::Plugin both roll their own. So I will do likewise. D'oh!
+#
+sub xml_encode {
+ my ($text) = @_;
+ $text =~ s/&/&/g;
+ $text =~ s/</</g;
+ $text =~ s/>/>/g;
+ $text =~ s/['']/'/g;
+ $text =~ s/[""]/"/g;
+ return $text;
+}
+
+
+# PRIVATE to irspy_namespace() and irspy_xpath_context()
+my %_namespaces = (
+ e => 'http://explain.z3950.org/dtd/2.0/',
+ i => $IRSPY_NS,
+ );
+
+
+sub irspy_namespace {
+ my($prefix) = @_;
+
+ my $uri = $_namespaces{$prefix};
+ die "irspy_namespace(): no URI for namespace prefix '$prefix'"
+ if !defined $uri;
+
+ return $uri;
+}
+
+
+sub irspy_xpath_context {
+ my($record) = @_;
+
+ my $xml = ref $record ? $record->render() : $record;
+ my $parser = new XML::LibXML();
+ my $doc = $parser->parse_string($xml);
+ my $root = $doc->getDocumentElement();
+ my $xc = XML::LibXML::XPathContext->new($root);
+ foreach my $prefix (keys %_namespaces) {
+ $xc->registerNs($prefix, $_namespaces{$prefix});
+ }
+ return $xc;
+}
+
+
+sub modify_xml_document {
+ my($xc, $fieldsByKey, $data) = @_;
+
+ my $nchanges = 0;
+ foreach my $key (keys %$data) {
+ my $value = $data->{$key};
+ my $ref = $fieldsByKey->{$key} or die "no field '$key'";
+ my($name, $nlines, $caption, $xpath, @addAfter) = @$ref;
+ #print "Considering $key='$value' ($xpath)<br/>\n";
+ my @nodes = $xc->findnodes($xpath);
+ if (@nodes) {
+ warn scalar(@nodes), " nodes match '$xpath'" if @nodes > 1;
+ my $node = $nodes[0];
+
+ if ($node->isa("XML::LibXML::Attr")) {
+ if ($value ne $node->getValue()) {
+ $node->setValue($value);
+ $nchanges++;
+ #print "Attr $key: '", $node->getValue(), "' -> '$value' ($xpath)<br/>\n";
+ }
+ } elsif ($node->isa("XML::LibXML::Element")) {
+ # The contents could be any mixture of text and
+ # comments and maybe even other crud such as processing
+ # instructions. The simplest thing is just to throw it all
+ # away and start again, making a single Text node the
+ # canonical representation. But before we do that,
+ # we'll check whether the element is already
+ # canonical, to determine whether our change is a
+ # no-op.
+ my $old = "???";
+ my @children = $node->childNodes();
+ if (@children == 1) {
+ my $child = $node->firstChild();
+ if (ref $child && ref $child eq "XML::LibXML::Text") {
+ $old = $child->getData();
+ next if $value eq $old;
+ }
+ }
+
+ $node->removeChildNodes();
+ my $child = new XML::LibXML::Text($value);
+ $node->appendChild($child);
+ $nchanges++;
+ #print "Elem $key: '$old' -> '$value' ($xpath)<br/>\n";
+ } else {
+ warn "unexpected node type $node";
+ }
+
+ } else {
+ next if !$value; # No need to create a new empty node
+ my($ppath, $element) = $xpath =~ /(.*)\/(.*)/;
+ dom_add_element($xc, $ppath, $element, $value, @addAfter);
+ #print "New $key ($xpath) = '$value'<br/>\n";
+ $nchanges++;
+ }
+ }
+
+ return $nchanges;
+}
+
+
+sub dom_add_element {
+ my($xc, $ppath, $element, $value, @addAfter) = @_;
+
+ #print "Adding $element='$value' at '$ppath' after (", join(", ", map { "'$_'" } @addAfter), ")<br/>\n";
+ my @nodes = $xc->findnodes($ppath);
+ if (@nodes == 0) {
+ # Oh dear, the parent node doesn't exist. We could make it,
+ # but for now let's not and say we did.
+ warn "no parent node '$ppath': not adding '$element'='$value'";
+ return;
+ }
+ warn scalar(@nodes), " nodes match parent '$ppath'" if @nodes > 1;
+ my $node = $nodes[0];
+
+ my(undef, $prefix, $nsElem) = $element =~ /((.*?):)?(.*)/;
+ my $new = new XML::LibXML::Element($nsElem);
+ $new->setNamespace(irspy_namespace($prefix), $prefix)
+ if $prefix ne "";
+
+ $new->appendText($value);
+ foreach my $predecessor (reverse @addAfter) {
+ my($child) = $xc->findnodes($predecessor, $node);
+ if (defined $child) {
+ $node->insertAfter($new, $child);
+ #print "Added after '$predecessor'<br/>\n";
+ return;
+ }
+ }
+
+ # Didn't find any of the nodes that are supposed to precede the
+ # new one, so we need to insert the new node as the first of the
+ # parent's children. However *sigh* there is no prependChild()
+ # analogous to appendChild(), so we have to go the long way round.
+ my @children = $node->childNodes();
+ if (@children) {
+ $node->insertBefore($new, $children[0]);
+ #print "Added new first child<br/>\n";
+ } else {
+ $node->appendChild($new);
+ #print "Added new only child<br/>\n";
+ }
+
+ if (0) {
+ my $text = xml_encode(inheritance_tree($xc));
+ $text =~ s/\n/<br\/>$&/sg;
+ print "<pre>$text</pre>\n";
+ }
+}
+
+
+sub inheritance_tree {
+ my($type, $level) = @_;
+ $level = 0 if !defined $level;
+ return "Woah! Too deep, man!\n" if $level > 20;
+
+ $type = ref $type if ref $type;
+ my $text = "";
+ $text = "--> " if $level == 0;
+ $text .= ("\t" x $level) . "$type\n";
+ my @ISA = eval "\@${type}::ISA";
+ foreach my $superclass (@ISA) {
+ $text .= inheritance_tree($superclass, $level+1);
+ }
+
+ return $text;
+}
+
+
+#print "Loaded ZOOM::IRSpy::Utils.pm";
+
1;
projects / irspy-moved-to-github.git / blobdiff