Moose::Meta::Method::Destructor - Method Meta Object for destructors


Moose documentation Contained in the Moose distribution.

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NAME

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Moose::Meta::Method::Destructor - Method Meta Object for destructors

VERSION

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version 2.0010

DESCRIPTION

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This class is a subclass of Class::MOP::Class::Generated that provides Moose-specific functionality for inlining destructors.

To understand this class, you should read the the Class::MOP::Class::Generated documentation as well.

INHERITANCE

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Moose::Meta::Method::Destructor is a subclass of Moose::Meta::Method and Class::MOP::Method::Generated.

METHODS

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Moose::Meta::Method::Destructor->new(%options)

This constructs a new object. It accepts the following options:

* package_name

The package for the class in which the destructor is being inlined. This option is required.

* name

The name of the destructor method. This option is required.

* metaclass

The metaclass for the class this destructor belongs to. This is optional, as it can be set later by calling $metamethod->attach_to_class.

Moose::Meta;:Method::Destructor->is_needed($metaclass)

Given a Moose::Meta::Class object, this method returns a boolean indicating whether the class needs a destructor. If the class or any of its parents defines a DEMOLISH method, it needs a destructor.

BUGS

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See BUGS in Moose for details on reporting bugs.

AUTHOR

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Stevan Little <stevan@iinteractive.com>

COPYRIGHT AND LICENSE

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Moose documentation Contained in the Moose distribution.

package Moose::Meta::Method::Destructor;
BEGIN {
  $Moose::Meta::Method::Destructor::AUTHORITY = 'cpan:STEVAN';
}
BEGIN {
  $Moose::Meta::Method::Destructor::VERSION = '2.0010';
}

use strict;
use warnings;

use Devel::GlobalDestruction ();
use Scalar::Util 'blessed', 'weaken';
use Try::Tiny;

use base 'Moose::Meta::Method',
         'Class::MOP::Method::Inlined';

sub new {
    my $class   = shift;
    my %options = @_;

    (ref $options{options} eq 'HASH')
        || $class->throw_error("You must pass a hash of options", data => $options{options});

    ($options{package_name} && $options{name})
        || $class->throw_error("You must supply the package_name and name parameters $Class::MOP::Method::UPGRADE_ERROR_TEXT");

    my $self = bless {
        # from our superclass
        'body'                 => undef,
        'package_name'         => $options{package_name},
        'name'                 => $options{name},
        # ...
        'options'              => $options{options},
        'definition_context'   => $options{definition_context},
        'associated_metaclass' => $options{metaclass},
    } => $class;

    # we don't want this creating
    # a cycle in the code, if not
    # needed
    weaken($self->{'associated_metaclass'});

    $self->_initialize_body;

    return $self;
}

## accessors

sub options              { (shift)->{'options'}              }

## method

sub is_needed {
    my $self      = shift;
    my $metaclass = shift;

    ( blessed $metaclass && $metaclass->isa('Class::MOP::Class') )
        || $self->throw_error(
        "The is_needed method expected a metaclass object as its arugment");

    return $metaclass->find_method_by_name("DEMOLISHALL");
}

sub initialize_body {
    Carp::cluck('The initialize_body method has been made private.'
        . " The public version is deprecated and will be removed in a future release.\n");
    shift->_initialize_body;
}

sub _initialize_body {
    my $self = shift;
    # TODO:
    # the %options should also include a both
    # a call 'initializer' and call 'SUPER::'
    # options, which should cover approx 90%
    # of the possible use cases (even if it
    # requires some adaption on the part of
    # the author, after all, nothing is free)

    my $class = $self->associated_metaclass->name;
    my @source = (
        'sub {',
            'my $self = shift;',
            'return ' . $self->_generate_fallback_destructor('$self'),
                'if Scalar::Util::blessed($self) ne \'' . $class . '\';',
            'local $?;',
            $self->_generate_DEMOLISHALL('$self'),
            'return;',
        '}',
    );
    warn join("\n", @source) if $self->options->{debug};

    my $code = try {
        $self->_compile_code(source => \@source);
    }
    catch {
        my $source = join("\n", @source);
        $self->throw_error(
            "Could not eval the destructor :\n\n$source\n\nbecause :\n\n$_",
            error => $_,
            data  => $source,
        );
    };

    $self->{'body'} = $code;
}

sub _generate_fallback_destructor {
    my $self = shift;
    my ($inv) = @_;

    return $inv . '->Moose::Object::DESTROY(@_)';
}

sub _generate_DEMOLISHALL {
    my $self = shift;
    my ($inv) = @_;

    my @methods = $self->associated_metaclass->find_all_methods_by_name('DEMOLISH');
    return unless @methods;

    return (
        'my $igd = Devel::GlobalDestruction::in_global_destruction;',
        'Try::Tiny::try {',
            (map { $inv . '->' . $_->{class} . '::DEMOLISH($igd);' } @methods),
        '}',
        'Try::Tiny::catch {',
            'die $_;',
        '};',
    );
}


1;

# ABSTRACT: Method Meta Object for destructors




__END__