[PATCH] Re: new fan has questions/comments/suggestions

[Daisuke Maki]

There's really no huge problem.  DateTime.pm would just have to skip the
relevant tests if a given formatter wasn't installed.  Since this would be
an optional feature, it'd be okay, I think.
Anyway, patches are still welcome.  I don't really need this, so I don't
think I'll be implementing it myself any time soon ;)
Patches, you say? (a simple test is also included at the bottom)
Let me know if this is okay, and I'll submit.
--d
Index: lib/DateTime.pm
===================================================================
RCS file: /cvsroot/perl-date-time/modules/DateTime.pm/lib/DateTime.pm,v
retrieving revision 1.286
diff -u -r1.286 DateTime.pm
--- lib/DateTime.pm     24 Jul 2004 19:30:00 -0000      1.286
+++ lib/DateTime.pm     2 Sep 2004 04:31:03 -0000
@@ -58,7 +58,7 @@
 use overload ( 'fallback' => 1,
                '<=>' => '_compare_overload',
                'cmp' => '_compare_overload',
-               '""'  => 'iso8601',
+               '""'  => 'format_datetime',
                '-'   => '_subtract_overload',
                '+'   => '_add_overload',
              );
@@ -157,6 +157,7 @@
     { %$BasicValidate,
       time_zone => { type => SCALAR | OBJECT,
                      default => 'floating' },
+      formatter => { type => SCALAR | OBJECT, optional => 1 }
     };
 sub new
@@ -194,7 +195,7 @@
         $class->_time_as_seconds( @p{ qw( hour minute second ) } );
     $self->{rd_nanosecs} = $p{nanosecond};
-
+    $self->{formatter} = $p{formatter};
     bless $self, $class;
     $self->_normalize_nanoseconds( $self->{local_rd_secs}, 
$self->{rd_nanosecs} );
@@ -340,6 +341,7 @@
                         locale     => { type => SCALAR | OBJECT, 
optional => 1 },
                         language   => { type => SCALAR | OBJECT, 
optional => 1 },
                         time_zone  => { type => SCALAR | OBJECT, 
optional => 1 },
+                        formatter  => { type => SCALAR | OBJECT, 
optional => 1 },
                       }
                     );

@@ -378,6 +380,7 @@
                                   },
                         locale     => { type => SCALAR | OBJECT, 
optional => 1 },
                         language   => { type => SCALAR | OBJECT, 
optional => 1 },
+                        formatter  => { type => SCALAR | OBJECT, 
optional => 1 },
                       },
                     );

@@ -481,6 +484,8 @@
                         );
 }
+sub formatter { $_[0]->{formatter} }
+
 sub clone { bless { %{ $_[0] } }, ref $_[0] }
 sub year    { $_[0]->{local_c}{year} }
@@ -612,6 +617,26 @@
     return DateTime->_leap_seconds( $self->{utc_rd_days} );
 }
+sub parse_datetime
+{
+    my $self = shift;
+    if (!$self->{formatter} || ! UNIVERSAL::can($self->{formatter}, 
'parse_datetime')) {
+        die "No formatter available (or specified formatter can't 
perform 'parse_datetime()')";
+    }
+    $self->{formatter}->parse_datetime($_[0]);
+}
+
+sub format_datetime
+{
+    my $self = shift;
+    if (!$self->{formatter} || ! UNIVERSAL::can($self->{formatter}, 
'format_datetime')) {
+        # XXX - could warn()
+        return $self->iso8601;
+    } else {
+        return $self->{formatter}->format_datetime($self);
+    }
+}
+
 sub hms
 {
     my ( $self, $sep ) = @_;
@@ -1358,6 +1383,8 @@

 sub set_locale { $_[0]->set( locale => $_[1] ) }
+sub set_formatter { $_[0]->{formatter} = $_[1] }
+
 sub truncate
 {
     my $self = shift;
And here's the test:
t/31formatter.t
#!/usr/bin/perl -w
use strict;
BEGIN
{
    eval { require DateTime::Format::Strptime };
    if ($@) {
        require Test::More;
        Test::More->import(skip_all => "DateTime::Format::Strptime not 
installed");
    }
    require Test::More;
    Test::More->import(tests => 6);
}

use DateTime;
my $formatter = DateTime::Format::Strptime->new(
    pattern => '%Y%m%d %T',
    locale  => 'en_US',
);
my $dt = DateTime->new(
    year => 2004,
    month => 9,
    day => 2,
    hour => 13,
    minute => 23,
    second => 34,
    formatter => $formatter
);
is($dt->format_datetime(), '20040902 13:23:34', 'Format datetime');
is($dt->compare($dt->parse_datetime($dt->format_datetime())), 0, 'Parse 
formatted datetime');

# check stringification (with formatter)
is($dt->format_datetime, "$dt", "Stringification (with formatter)");
# check if the default behavior works
$dt->set_formatter(undef);
is($dt->format_datetime(), $dt->iso8601, 'Default iso8601 works');
# check stringification (default)
is($dt->format_datetime, "$dt", "Stringification (no formatter -> 
format_datetime)");
is($dt->iso8601, "$dt", "Stringification (no formatter -> iso8601)");