X-Git-Url: http://git.indexdata.com/?p=irspy-moved-to-github.git;a=blobdiff_plain;f=lib%2FZOOM%2FIRSpy%2FUtils.pm;h=13ef7ae229256f808169cec45b0e89e70fcec13f;hp=c1399950d87cbfcba28c33ef71068bc3814ec11d;hb=9c00eb84ce3c8edf1ba18c60e62aa53c0f072230;hpb=01db8593a91d42a9dc554edc17d0c2c1b3858ef5

diff --git a/lib/ZOOM/IRSpy/Utils.pm b/lib/ZOOM/IRSpy/Utils.pm
index c139995..13ef7ae 100644
--- a/lib/ZOOM/IRSpy/Utils.pm
+++ b/lib/ZOOM/IRSpy/Utils.pm
@@ -1,4 +1,4 @@
-# $Id: Utils.pm,v 1.2 2006-10-30 16:13:49 mike Exp $
+# $Id: Utils.pm,v 1.9 2006-11-09 16:09:35 mike Exp $
 
 package ZOOM::IRSpy::Utils;
 
@@ -7,7 +7,15 @@ use strict;
 use warnings;
 
 use Exporter 'import';
-our @EXPORT_OK = qw(xml_encode irspy_xpath_context);
+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
@@ -28,18 +36,169 @@ sub xml_encode {
 }
 
 
+# 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 $uri;
+}
+
+
 sub irspy_xpath_context {
-    my($zoom_record) = @_;
+    my($record) = @_;
 
-    my $xml = $zoom_record->render();
+    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);
-    $xc->registerNs(e => 'http://explain.z3950.org/dtd/2.0/');
-    $xc->registerNs(i => $ZOOM::IRSpy::irspy_ns);
+    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;