# $Id: Utils.pm,v 1.17 2006-11-29 18:15:10 mike Exp $ package ZOOM::IRSpy::Utils; use 5.008; use strict; use warnings; use Exporter 'import'; our @EXPORT_OK = qw(isodate xml_encode cql_quote cql_target irspy_xpath_context modify_xml_document); use XML::LibXML; use XML::LibXML::XPathContext; our $IRSPY_NS = 'http://indexdata.com/irspy/1.0'; # Utility functions follow, exported for use of web UI sub isodate { my($time) = @_; my($sec, $min, $hour, $mday, $mon, $year) = localtime($time); return sprintf("%04d-%02d-%02dT%02d:%02d:%02d", $year+1900, $mon+1, $mday, $hour, $min, $sec); } # I can't -- just can't, can't, can't -- believe that this function # isn't provided by one of the core XML modules. But the evidence all # says that it's not: among other things, XML::Generator and # Template::Plugin both roll their own. So I will do likewise. D'oh! # sub xml_encode { my($text, $fallback) = @_; $text = $fallback if !defined $text; use Carp; confess "xml_encode(): text and fallback both undefined" if !defined $text; $text =~ s/&/&/g; $text =~ s//>/g; $text =~ s/['']/'/g; $text =~ s/[""]/"/g; return $text; } # Quotes a term for use in a CQL query sub cql_quote { my($term) = @_; $term =~ s/([""\\])/\\$1/g; $term = qq["$term"] if $term =~ /\s/; return $term; } # Makes a CQL query that finds a specified target sub cql_target { my($host, $port, $db) = @_; return ("host=" . cql_quote($host) . " and " . "port=" . cql_quote($port) . " and " . "path=" . cql_quote($db)); } # 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) = @_; use Carp; confess "irspy_namespace(undef)" if !defined $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 @changes = (); 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)
\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); push @changes, $ref; #print "Attr $key: '", $node->getValue(), "' -> '$value' ($xpath)
\n"; } } elsif ($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); push @changes, $ref; #print "Elem $key: '$old' -> '$value' ($xpath)
\n"; } else { warn "unexpected node type $node"; } } else { next if !$value; # No need to create a new empty node my($ppath, $selector) = $xpath =~ /(.*)\/(.*)/; dom_add_node($xc, $ppath, $selector, $value, @addAfter); #print "New $key ($xpath) = '$value'
\n"; push @changes, $ref; } } return @changes; } sub dom_add_node { my($xc, $ppath, $selector, $value, @addAfter) = @_; #print "Adding $selector='$value' at '$ppath' after (", join(", ", map { "'$_'" } @addAfter), ")
\n"; my $node = find_or_make_node($xc, $ppath, 0); die "couldn't find or make node '$node'" if !defined $node; my $is_attr = ($selector =~ s/^@//); my(undef, $prefix, $simpleSel) = $selector =~ /((.*?):)?(.*)/; #warn "selector='$selector', prefix='$prefix', simpleSel='$simpleSel'"; if ($is_attr) { if (defined $prefix) { ### This seems to no-op (thank, DOM!) but I have have no # idea, and it's not needed for IRSpy, so I am not going # to debug it now. $node->setAttributeNS(irspy_namespace($prefix), $simpleSel, $value); } else { $node->setAttribute($simpleSel, $value); } return; } my $new = new XML::LibXML::Element($simpleSel); $new->setNamespace(irspy_namespace($prefix), $prefix) if defined $prefix; $new->appendText($value); foreach my $predecessor (reverse @addAfter) { my($child) = $xc->findnodes($predecessor, $node); if (defined $child) { $node->insertAfter($new, $child); #warn "Added after '$predecessor'"; 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]); #warn "Added new first child"; } else { $node->appendChild($new); #warn "Added new only child"; } if (0) { my $text = xml_encode(inheritance_tree($xc)); $text =~ s/\n/$&/sg; print "
$text
\n"; } } sub find_or_make_node { my($xc, $path, $recursion_level) = @_; die "deep recursion in find_or_make_node($path)" if $recursion_level == 10; $path = "." if $path eq ""; my @nodes = $xc->findnodes($path); if (@nodes == 0) { # Oh dear, the parent node doesn't exist. We could make it, my(undef, $ppath, $element) = $path =~ /((.*)\/)?(.*)/; $ppath = "" if !defined $ppath; #warn "path='$path', ppath='$ppath', element='$element'"; #warn "no node '$path': making it"; my $parent = find_or_make_node($xc, $ppath, $recursion_level-1); my(undef, $prefix, $nsElem) = $element =~ /((.*?):)?(.*)/; #warn "element='$element', prefix='$prefix', nsElem='$nsElem'"; my $new = new XML::LibXML::Element($nsElem); if (defined $prefix) { #warn "setNamespace($prefix)"; $new->setNamespace(irspy_namespace($prefix), $prefix); } $parent->appendChild($new); return $new; } warn scalar(@nodes), " nodes match parent '$path'" if @nodes > 1; return $nodes[0]; } sub inheritance_tree { my($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;