Perl::Critic::PolicyParameter::Behavior::Enumeration - Actions appropriate for an enumerated value.

Perl-Critic documentation Contained in the Perl-Critic distribution.

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NAME

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Perl::Critic::PolicyParameter::Behavior::Enumeration - Actions appropriate for an enumerated value.

DESCRIPTION

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Provides a standard set of functionality for an enumerated Perl::Critic::PolicyParameter so that the developer of a policy does not have to provide it her/himself.

NOTE: Do not instantiate this class. Use the singleton instance held onto by Perl::Critic::PolicyParameter.

INTERFACE SUPPORT

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This is considered to be a non-public class. Its interface is subject to change without notice.

METHODS

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initialize_parameter( $parameter, $specification )

Plug in the functionality this behavior provides into the parameter, based upon the configuration provided by the specification.

This behavior looks for two configuration items:

enumeration_values

Mandatory. The set of valid values for the parameter, as an array reference.

enumeration_allow_multiple_values

Optional, defaults to false. Should the parameter support a single value or accept multiple?

generate_parameter_description( $parameter )

Create a description of the parameter, based upon the description on the parameter itself, but enhancing it with information from this behavior.

In this specific case, the universe of values is added at the end.

AUTHOR

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Elliot Shank <perl@galumph.com>

COPYRIGHT

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Copyright (c) 2006-2011 Elliot Shank.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of this license can be found in the LICENSE file included with this module.

Perl-Critic documentation Contained in the Perl-Critic distribution. 
##############################################################################
#      $URL: http://perlcritic.tigris.org/svn/perlcritic/trunk/distributions/Perl-Critic/lib/Perl/Critic/PolicyParameter/Behavior/Enumeration.pm $
#     $Date: 2011-05-15 16:34:46 -0500 (Sun, 15 May 2011) $
#   $Author: clonezone $
# $Revision: 4078 $
##############################################################################

package Perl::Critic::PolicyParameter::Behavior::Enumeration;

use 5.006001;
use strict;
use warnings;

use Perl::Critic::Exception::Fatal::PolicyDefinition
    qw{ &throw_policy_definition };
use Perl::Critic::Utils qw{ :characters &words_from_string &hashify };

use base qw{ Perl::Critic::PolicyParameter::Behavior };

our $VERSION = '1.116';

#-----------------------------------------------------------------------------

sub initialize_parameter {
    my ($self, $parameter, $specification) = @_;

    my $valid_values = $specification->{enumeration_values}
        or throw_policy_definition
            'No enumeration_values given for '
                . $parameter->get_name()
                . $PERIOD;
    ref $valid_values eq 'ARRAY'
        or throw_policy_definition
            'The value given for enumeration_values for '
                . $parameter->get_name()
                . ' is not an array reference.';
    scalar @{$valid_values} > 1
        or throw_policy_definition
            'There were not at least two valid values given for'
                . ' enumeration_values for '
                . $parameter->get_name()
                . $PERIOD;

    # Unfortunately, this has to be a reference, rather than a regular hash,
    # due to a problem in Devel::Cycle
    # (http://rt.cpan.org/Ticket/Display.html?id=25360) which causes
    # t/92_memory_leaks.t to fall over.
    my $value_lookup = { hashify( @{$valid_values} ) };
    $parameter->_get_behavior_values()->{enumeration_values} = $value_lookup;

    my $allow_multiple_values =
        $specification->{enumeration_allow_multiple_values};

    if ($allow_multiple_values) {
        $parameter->_set_parser(
            sub {
                # Normally bad thing, obscuring a variable in a outer scope
                # with a variable with the same name is being done here in
                # order to remain consistent with the parser function interface.
                my ($policy, $parameter, $config_string) = @_;  ## no critic(Variables::ProhibitReusedNames)

                my @potential_values;
                my $value_string = $parameter->get_default_string();

                if (defined $config_string) {
                    $value_string = $config_string;
                }

                if ( defined $value_string ) {
                    @potential_values = words_from_string($value_string);

                    my @bad_values =
                        grep { not exists $value_lookup->{$_} } @potential_values;
                    if (@bad_values) {
                        $policy->throw_parameter_value_exception(
                            $parameter->get_name(),
                            $value_string,
                            undef,
                            q{contains invalid values: }
                                . join (q{, }, @bad_values)
                                . q{. Allowed values are: }
                                . join (q{, }, sort keys %{$value_lookup})
                                . qq{.\n},
                        );
                    }
                }

                my %actual_values = hashify(@potential_values);

                $policy->__set_parameter_value($parameter, \%actual_values);

                return;
            }
        );
    } else {
        $parameter->_set_parser(
            sub {
                # Normally bad thing, obscuring a variable in a outer scope
                # with a variable with the same name is being done here in
                # order to remain consistent with the parser function interface.
                my ($policy, $parameter, $config_string) = @_;  ## no critic(Variables::ProhibitReusedNames)

                my $value_string = $parameter->get_default_string();

                if (defined $config_string) {
                    $value_string = $config_string;
                }

                if (
                        defined $value_string
                    and $EMPTY ne $value_string
                    and not defined $value_lookup->{$value_string}
                ) {
                    $policy->throw_parameter_value_exception(
                        $parameter->get_name(),
                        $value_string,
                        undef,
                        q{is not one of the allowed values: }
                            . join (q{, }, sort keys %{$value_lookup})
                            . qq{.\n},
                    );
                }

                $policy->__set_parameter_value($parameter, $value_string);

                return;
            }
        );
    }

    return;
}

#-----------------------------------------------------------------------------

sub generate_parameter_description {
    my ($self, $parameter) = @_;

    my $description = $parameter->_get_description_with_trailing_period();
    if ( $description ) {
        $description .= qq{\n};
    }

    my %values = %{$parameter->_get_behavior_values()->{enumeration_values}};
    return
        $description
        . 'Valid values: '
        . join (', ', sort keys %values)
        . $PERIOD;
}

#-----------------------------------------------------------------------------

1;

__END__

#-----------------------------------------------------------------------------


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