HH::Unispool::Config::DateFormat - UNISPOOL date format

 use strict;

 use HH::Unispool::Config;
 use HH::Unispool::Config::OS;
 use HH::Unispool::Config::Scope;
 use HH::Unispool::Config::DateFormat;
 use HH::Unispool::Config::Entry::System;

 # Create a config from scratch with a _Local_ scope
 my $conf = HH::Unispool::Config->new( {
     scope => HH::Unispool::Config::Scope->new ( {
         scope => [ qw( _Local_) ],
     } ),
 } );

 # Create the _Local_ system and add it to the configuration
 my $sysn = HH::Unispool::Config::Entry::System->new( {
     name => '_Local_',
     local_system_name => 'foo',
     network_name => 'foo.bar.org',
     os => HH::Unispool::Config::OS->new( {
         os => 'Solaris',
     } ),
     date_format => HH::Unispool::Config::DateFormat->new( {
         date_format => 'YY/MM/DD',
     } ),
 } );
 $conf->add_system($sysn);

 # Write the configuration
 $conf->write('t/config.sample.d0.out');

package HH::Unispool::Config::DateFormat;

use 5.006;
use strict;
use warnings;
use AutoLoader qw(AUTOLOAD);
use Error qw(:try);

# Used by _value_is_allowed
our %ALLOW_ISA = (
);

# Used by _value_is_allowed
our %ALLOW_REF = (
);

# Used by _value_is_allowed
our %ALLOW_RX = (
);

# Used by _value_is_allowed
our %ALLOW_VALUE = (
    'date_format' => {
        'DD/MM/YY' => 1,
        'DD/MMM/YY' => 1,
        'MM/DD/YY' => 1,
        'YY/MM/DD' => 1,
    },
);

# Used by _initialize
our %DEFAULT_VALUE = (
    'date_format' => 'DD/MM/YY',
);

# Package version
our ($VERSION) = '$Revision: 0.3 $' =~ /\$Revision:\s+([^\s]+)/;

1;

__END__

sub new {
    my $class = shift;

    my $self = {};
    bless( $self, ( ref($class) || $class ) );
    return( $self->_initialize(@_) );
}

sub _initialize {
    my $self = shift;
    my $opt = defined($_[0]) ? shift : {};

    # Check $opt
    ref($opt) eq 'HASH' || throw Error::Simple("ERROR: HH::Unispool::Config::DateFormat::_initialize, first argument must be 'HASH' reference.");

    # date_format, SINGLE, mandatory, with default value
    exists( $opt->{date_format} ) || throw Error::Simple("ERROR: HH::Unispool::Config::DateFormat::_initialize, option 'date_format' is mandatory.");
    $self->set_date_format( $opt->{date_format} );

    # Return $self
    return($self);
}

sub _value_is_allowed {
    my $name = shift;

    # Value is allowed if no ALLOW clauses exist for the named attribute
    if ( ! exists( $ALLOW_ISA{$name} ) && ! exists( $ALLOW_REF{$name} ) && ! exists( $ALLOW_RX{$name} ) && ! exists( $ALLOW_VALUE{$name} ) ) {
        return(1);
    }

    # At this point, all values in @_ must to be allowed
    CHECK_VALUES:
    foreach my $val (@_) {
        # Check ALLOW_ISA
        if ( ref($val) && exists( $ALLOW_ISA{$name} ) ) {
            foreach my $class ( @{ $ALLOW_ISA{$name} } ) {
                &UNIVERSAL::isa( $val, $class ) && next CHECK_VALUES;
            }
        }

        # Check ALLOW_REF
        if ( ref($val) && exists( $ALLOW_REF{$name} ) ) {
            exists( $ALLOW_REF{$name}{ ref($val) } ) && next CHECK_VALUES;
        }

        # Check ALLOW_RX
        if ( defined($val) && ! ref($val) && exists( $ALLOW_RX{$name} ) ) {
            foreach my $rx ( @{ $ALLOW_RX{$name} } ) {
                $val =~ /$rx/ && next CHECK_VALUES;
            }
        }

        # Check ALLOW_VALUE
        if ( ! ref($val) && exists( $ALLOW_VALUE{$name} ) ) {
            exists( $ALLOW_VALUE{$name}{$val} ) && next CHECK_VALUES;
        }

        # We caught a not allowed value
        return(0);
    }

    # OK, all values are allowed
    return(1);
}

sub diff {
    my $from = shift;
    my $to = shift;

    # Reference types must be identical
    if ( ref($from) ne ref($to) ) {
        my $rf = ref($from);
        my $rt = ref($to);

        throw Error::Simple("ERROR: HH::Unispool::Config::DateFormat::diff, FROM ($rf) and TO ($rt) reference types differ.");
    }

    # Diff message
    my $diff = '';

    # Diff the date formats
    if ( $from->get_date_format() ne $to->get_date_format() ) {
        my $vf = $from->get_date_format();
        my $vt = $to->get_date_format();
        $diff .= "Date formats differ: $vf <-> $vt\n";
    }

    # Return diff
    return($diff);
}

sub get_date_format {
    my $self = shift;

    return( $self->{HH_Unispool_Config_DateFormat}{date_format} );
}

sub set_date_format {
    my $self = shift;
    my $val = shift;

    # Check if isa/ref/rx/value is allowed
    &_value_is_allowed( 'date_format', $val ) || throw Error::Simple("ERROR: HH::Unispool::Config::DateFormat::set_date_format, the specified value '$val' is not allowed.");

    # Assignment
    $self->{HH_Unispool_Config_DateFormat}{date_format} = $val;
}