# $Id: Utils.pm,v 1.20 2006-12-11 13:58:17 sondberg 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, $opts) = @_;
if (!defined $opts && ref $fallback) {
# The second and third arguments are both optional
$opts = $fallback;
$fallback = undef;
}
$opts = {} if !defined $opts;
$text = $fallback if !defined $text;
use Carp;
confess "xml_encode(): text and fallback both undefined"
if !defined $text;
$text =~ s/&/&/g;
$text =~ s/</g;
$text =~ s/>/>/g;
# Internet Explorer can't display ' (!) so don't create it
#$text =~ s/['']/'/g;
$text =~ s/[""]/"/g;
$text =~ s/ / /g if $opts->{nbsp};
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 $text; } # This function is made available in xslt using the register_function call sub xslt_strcmp { my ($arg1, $arg2) = @_; return ($arg1->to_literal()) cmp ($arg2->to_literal()); } 1;