New function modify_xml_document()

[irspy-moved-to-github.git] / lib / ZOOM / IRSpy / Utils.pm

diff --git a/lib/ZOOM/IRSpy/Utils.pm b/lib/ZOOM/IRSpy/Utils.pm
index 61636c4..ca111ce 100644 (file)
--- a/lib/ZOOM/IRSpy/Utils.pm
+++ b/lib/ZOOM/IRSpy/Utils.pm
@@ -1,4 +1,4 @@
-# $Id: Utils.pm,v 1.1 2006-10-30 15:02:06 mike Exp $
+# $Id: Utils.pm,v 1.4 2006-11-01 10:13:26 mike Exp $
 
 package ZOOM::IRSpy::Utils;
 
@@ -6,6 +6,139 @@ use 5.008;
 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/</&lt;/g;
+    $text =~ s/>/&gt;/g;
+    $text =~ s/['']/&apos;/g;
+    $text =~ s/[""]/&quot;/g;
+    return $text;
+}
+
+
+sub irspy_xpath_context {
+    my($zoom_record) = @_;
+
+    my $xml = $zoom_record->render();
+    my $parser = new XML::LibXML();
+    my $doc = $parser->parse_string($xml);
+    my $root = $doc->getDocumentElement();
+    my $xc = XML::LibXML::XPathContext->new($root);
+    $xc->registerNs(e => 'http://explain.z3950.org/dtd/2.0/');
+    $xc->registerNs(i => $IRSPY_NS);
+    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")) {
+               my $child = $node->firstChild();
+               ### Next line fails if data contains a comment ... *sigh*
+               die "element child $child is not text"
+                   if !ref $child || !$child->isa("XML::LibXML::Text");
+               if ($value ne $child->getData()) {
+                   $child->setData($value);
+                   $nchanges++;
+                   print "Elem $key: '", $child->getData(), "' -> '$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 "Add $key ($xpath) = '$value'<br/>\n";
+           $nchanges++;
+       }
+    }
+
+    return $nchanges;
+}
+
+
+sub dom_add_element {
+    my($xc, $ppath, $element, $value, @addAfter) = @_;
+
+    print "Adding '$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];
+
+    if (1) {
+       my $text = xml_encode(inheritance_tree($xc));
+       $text =~ s/\n/<br\/>$1/sg;
+       print "<pre>$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;