deprecated/buildtools/buildsystemtools/lib/XML/XQL/Date.pm
changeset 662 60be34e1b006
parent 655 3f65fd25dfd4
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/deprecated/buildtools/buildsystemtools/lib/XML/XQL/Date.pm	Wed Oct 27 16:03:51 2010 +0800
@@ -0,0 +1,206 @@
+############################################################################
+# Copyright (c) 1998 Enno Derksen
+# All rights reserved.
+# This program is free software; you can redistribute it and/or modify it
+# under the same terms as Perl itself. 
+############################################################################
+
+package XML::XQL::Date;
+
+use vars qw(@ISA);
+@ISA = qw( XML::XQL::PrimitiveType );
+
+use strict;
+use Carp;
+
+BEGIN
+{
+    # Date::Manip relies on setting of $TZ. 
+    unless (defined $ENV{TZ})
+    {
+	$ENV{TZ} = "EST5EDT";
+	warn "XML::XQL::Date - setting timezone \$ENV{TZ} to EST5EDT (east coast USA.) Set your TZ environment variable to avoid this message.";
+    }
+}
+use Date::Manip;
+
+BEGIN {
+    # add date() implementation to XQL engine.
+    XML::XQL::defineFunction ("date", \&XML::XQL::Date::date, 1, 1, 1);
+};
+
+use overload 
+    'fallback' => 1,		# use default operators, if not specified
+    '<=>' => \&compare,		# also takes care of <, <=, ==, != etc.
+    'cmp' => \&compare,		# also takes care of le, lt, eq, ne, etc.
+    '""'  => \&yyyymmddhhmmss;	# conversion to string uses yyyymmddhhmmss
+
+sub new
+{
+    my $class = shift;
+
+    my (%args);
+    if (@_ < 2)
+    {
+	my $str = @_ ? $_[0] : "";
+	%args = (String => $str);
+    }
+    else
+    {
+	%args = @_;
+    }
+
+    my $self = bless \%args, $class;
+
+    if (@_ < 2)
+    {
+	my $date = $self->createInternal (@_ ? $_[0] : "now");
+	$date = "" unless isValidDate ($date);
+	$self->{Internal} = $date;
+    }
+    $self;
+}
+
+sub createInternal
+{
+    my ($self, $str) = @_;
+    Date::Manip::ParseDate ($str);
+
+# From Date::Manip:
+#
+# 2 digit years fall into the 100 year period given by [ CURR-N,
+# CURR+(99-N) ] where N is 0-99.  Default behavior is 89, but other useful
+# numbers might be 0 (forced to be this year or later) and 99 (forced to be
+# this year or earlier).  It can also be set to "c" (current century) or
+# "cNN" (i.e.  c18 forces the year to bet 1800-1899).  Also accepts the
+# form cNNNN to give the 100 year period NNNN to NNNN+99.
+#$Date::Manip::YYtoYYYY=89;
+
+# Use this to force the current date to be set to this:
+#$Date::Manip::ForceDate="";
+}
+
+sub isValidDate		# static method
+{
+    my ($date) = @_;
+    return 0 unless defined $date;
+
+    my $year = substr ($date, 0, 4) || 0;
+
+    $year > 1500;
+#?? arbitrary limit - years < 100 cause problems in Date::Manip
+}
+
+sub ymdhms
+{
+    my $self = shift;
+    if (@_)
+    {
+	my ($y, $mon, $d, $h, $m, $s) = @;
+#?? implement
+    }
+    else
+    {
+#?? test: x skips a character. Format: "YYYYMMDDhh:mm::ss"
+	return () unless length $self->{Internal};
+#	print "ymhds " . $self->{Internal} . "\n";
+	unpack ("A4A2A2A2xA2xA2", $self->{Internal});
+    }
+}
+
+sub yyyymmddhhmmss
+{
+    my ($self) = @_;
+    my ($y, $mon, $d, $h, $m, $s) = $self->ymdhms;
+    
+    $y ? "$y-$mon-${d}T$h:$m:$s" : "";
+    # using Date::Manip::UnixDate is a bit too slow for my liking
+#?? could add support for other formats
+}
+
+sub xql_toString
+{
+#?? use $_[0]->{String} or 
+    $_[0]->yyyymmddhhmmss;
+}
+
+sub xql_compare
+{
+    my ($self, $other) = @_;
+    my $type = ref ($self);
+    if (ref ($other) ne $type)
+    {
+	my $str = $other->xql_toString;
+	# Allow users to plug in their own Date class
+	$other = eval "new $type (\$str)";
+#?? check result?
+    }
+#print "date::compare self=" . $self->{Internal} . " other=" . $other->{Internal}. "\n";
+    $self->{Internal} cmp $other->{Internal};
+}
+
+sub xql_setSourceNode
+{
+    $_[0]->{SourceNode} = $_[1];
+}
+
+sub xql_sourceNode
+{
+    $_[0]->{SourceNode};
+}
+
+sub xql_setValue
+{
+    my ($self, $val) = @_;
+    $self->{Internal} = $self->createInternal ($val);
+    $self->{String} = $val;
+}
+
+# The XQL date() function
+sub date	# static method
+{
+    my ($context, $listref, $text) = @_;
+
+    $text = XML::XQL::toList ($text->solve ($context, $listref));
+    my @result = ();
+    for my $val (@$text)
+    {
+	# Using xql_new allows users to plug-in their own Date class
+	my $date = XML::XQL::xql_new ("date", $val->xql_toString);
+#	print "date $val " . XML::XQL::d($val) . " " . $date->xql_toString . "\n";
+	push @result, $date;
+    }
+    \@result;
+}
+
+1; # module return code
+
+__END__
+
+=head1 NAME
+
+XML::XQL::Date - Adds an XQL::Node type for representing and comparing dates and times
+
+=head1 SYNOPSIS
+
+ use XML::XQL;
+ use XML::XQL::Date;
+
+ my $query = new XML::XQL::Query (Expr => "doc//timestamp[. < date('12/31/1999')]");
+ my @results = $query->solve ($doc);
+
+=head1 DESCRIPTION
+
+This package uses the L<Date::Manip> package to add an XQL node type 
+(called XML::XQL::Date) that can be used to represent dates and times. 
+The Date::Manip package can parse almost any date or time format imaginable.
+(I tested it with Date::Manip 5.33 and I know for sure that it doesn't work 
+with 5.20 or lower.)
+
+It also adds the XQL B<date> function which creates an XML::XQL::Date 
+object from a string. See L<XML::XQL::Tutorial> for a description of the date()
+function.
+
+You can plug in your own Date type, if you don't want to use Date::Manip 
+ for some reason. See L<XML::XQL> and the XML::XQL::Date source file for
+more details.