use strict;
use warnings;
-our $VERSION = '0.27';
+our $VERSION = '0.56';
our $AUTHORITY = 'cpan:STEVAN';
-use Scalar::Util 'blessed', 'reftype';
-use Carp 'confess';
-use Sub::Name 'subname';
-use B 'svref_2object';
+use Scalar::Util 'blessed';
+use Carp 'confess', 'croak', 'cluck';
-use Sub::Exporter;
+use Moose::Exporter;
-use Class::MOP 0.39;
+use Class::MOP 0.64;
use Moose::Meta::Class;
use Moose::Meta::TypeConstraint;
use Moose::Object;
use Moose::Util::TypeConstraints;
+use Moose::Util ();
-{
- my $CALLER;
+sub extends {
+ my $class = shift;
- sub init_meta {
- my ( $class, $base_class, $metaclass ) = @_;
- $base_class = $class unless defined $base_class;
- $metaclass = 'Moose::Meta::Class' unless defined $metaclass;
+ croak "Must derive at least one class" unless @_;
- confess
- "The Metaclass $metaclass must be a subclass of Moose::Meta::Class."
- unless $metaclass->isa('Moose::Meta::Class');
+ my @supers = @_;
+ foreach my $super (@supers) {
+ Class::MOP::load_class($super);
+ croak "You cannot inherit from a Moose Role ($super)"
+ if $super->can('meta') &&
+ blessed $super->meta &&
+ $super->meta->isa('Moose::Meta::Role')
+ }
- # make a subtype for each Moose class
- subtype $class => as 'Object' => where { $_->isa($class) } =>
- optimize_as { blessed( $_[0] ) && $_[0]->isa($class) }
- unless find_type_constraint($class);
- my $meta;
- if ( $class->can('meta') ) {
- # NOTE:
- # this is the case where the metaclass pragma
- # was used before the 'use Moose' statement to
- # override a specific class
- $meta = $class->meta();
- ( blessed($meta) && $meta->isa('Moose::Meta::Class') )
- || confess
-"You already have a &meta function, but it does not return a Moose::Meta::Class";
- }
- else {
- # NOTE:
- # this is broken currently, we actually need
- # to allow the possiblity of an inherited
- # meta, which will not be visible until the
- # user 'extends' first. This needs to have
- # more intelligence to it
- $meta = $metaclass->initialize($class);
- $meta->add_method(
- 'meta' => sub {
-
- # re-initialize so it inherits properly
- $metaclass->initialize( blessed( $_[0] ) || $_[0] );
- }
- );
- }
-
- # make sure they inherit from Moose::Object
- $meta->superclasses($base_class)
- unless $meta->superclasses();
- }
- my %exports = (
- extends => sub {
- my $class = $CALLER;
- return subname 'Moose::extends' => sub (@) {
- confess "Must derive at least one class" unless @_;
- Class::MOP::load_class($_) for @_;
-
- # this checks the metaclass to make sure
- # it is correct, sometimes it can get out
- # of sync when the classes are being built
- my $meta = $class->meta->_fix_metaclass_incompatability(@_);
- $meta->superclasses(@_);
- };
- },
- with => sub {
- my $class = $CALLER;
- return subname 'Moose::with' => sub (@) {
- my (@roles) = @_;
- confess "Must specify at least one role" unless @roles;
- Class::MOP::load_class($_) for @roles;
- $class->meta->_apply_all_roles(@roles);
- };
- },
- has => sub {
- my $class = $CALLER;
- return subname 'Moose::has' => sub ($;%) {
- my ( $name, %options ) = @_;
- my $attrs = ( ref($name) eq 'ARRAY' ) ? $name : [ ($name) ];
- $class->meta->_process_attribute( $_, %options ) for @$attrs;
- };
- },
- before => sub {
- my $class = $CALLER;
- return subname 'Moose::before' => sub (@&) {
- my $code = pop @_;
- my $meta = $class->meta;
- $meta->add_before_method_modifier( $_, $code ) for @_;
- };
- },
- after => sub {
- my $class = $CALLER;
- return subname 'Moose::after' => sub (@&) {
- my $code = pop @_;
- my $meta = $class->meta;
- $meta->add_after_method_modifier( $_, $code ) for @_;
- };
- },
- around => sub {
- my $class = $CALLER;
- return subname 'Moose::around' => sub (@&) {
- my $code = pop @_;
- my $meta = $class->meta;
- $meta->add_around_method_modifier( $_, $code ) for @_;
- };
- },
- super => sub {
- {
- our %SUPER_SLOT;
- no strict 'refs';
- $SUPER_SLOT{$CALLER} = \*{"${CALLER}::super"};
- }
- return subname 'Moose::super' => sub { };
- },
- override => sub {
- my $class = $CALLER;
- return subname 'Moose::override' => sub ($&) {
- my ( $name, $method ) = @_;
- $class->meta->add_override_method_modifier( $name => $method );
- };
- },
- inner => sub {
- {
- our %INNER_SLOT;
- no strict 'refs';
- $INNER_SLOT{$CALLER} = \*{"${CALLER}::inner"};
- }
- return subname 'Moose::inner' => sub { };
- },
- augment => sub {
- my $class = $CALLER;
- return subname 'Moose::augment' => sub (@&) {
- my ( $name, $method ) = @_;
- $class->meta->add_augment_method_modifier( $name => $method );
- };
- },
+ # this checks the metaclass to make sure
+ # it is correct, sometimes it can get out
+ # of sync when the classes are being built
+ my $meta = $class->meta->_fix_metaclass_incompatability(@supers);
+ $meta->superclasses(@supers);
+}
- # NOTE:
- # this is experimental, but I am not
- # happy with it. If you want to try
- # it, you will have to uncomment it
- # yourself.
- # There is a really good chance that
- # this will be deprecated, dont get
- # too attached
- # self => sub {
- # return subname 'Moose::self' => sub {};
- # },
- # method => sub {
- # my $class = $CALLER;
- # return subname 'Moose::method' => sub {
- # my ($name, $method) = @_;
- # $class->meta->add_method($name, sub {
- # my $self = shift;
- # no strict 'refs';
- # no warnings 'redefine';
- # local *{$class->meta->name . '::self'} = sub { $self };
- # $method->(@_);
- # });
- # };
- # },
-
- confess => sub {
- return \&Carp::confess;
- },
- blessed => sub {
- return \&Scalar::Util::blessed;
- },
- );
-
- my $exporter = Sub::Exporter::build_exporter(
- {
- exports => \%exports,
- groups => { default => [':all'] }
- }
- );
-
- # 1 extra level because it's called by import so there's a layer of indirection
- sub _get_caller{
- my $offset = 1;
- return
- ref $_[1] && defined $_[1]->{into}
- ? $_[1]->{into}
- : ref $_[1] && defined $_[1]->{into_level}
- ? caller($offset + $_[1]->{into_level})
- : caller($offset);
- }
+sub with {
+ my $class = shift;
+ Moose::Util::apply_all_roles($class->meta, @_);
+}
- sub import {
- $CALLER = _get_caller(@_);
-
- strict->import;
- warnings->import;
+sub has {
+ my $class = shift;
+ my $name = shift;
+ croak 'Usage: has \'name\' => ( key => value, ... )' if @_ == 1;
+ my %options = @_;
+ my $attrs = ( ref($name) eq 'ARRAY' ) ? $name : [ ($name) ];
+ $class->meta->add_attribute( $_, %options ) for @$attrs;
+}
- # we should never export to main
- return if $CALLER eq 'main';
+sub before {
+ my $class = shift;
+ Moose::Util::add_method_modifier($class, 'before', \@_);
+}
+
+sub after {
+ my $class = shift;
+ Moose::Util::add_method_modifier($class, 'after', \@_);
+}
- init_meta( $CALLER, 'Moose::Object' );
+sub around {
+ my $class = shift;
+ Moose::Util::add_method_modifier($class, 'around', \@_);
+}
+
+sub super {
+ return unless our $SUPER_BODY; $SUPER_BODY->(our @SUPER_ARGS);
+}
+
+sub override {
+ my $class = shift;
+ my ( $name, $method ) = @_;
+ $class->meta->add_override_method_modifier( $name => $method );
+}
- goto $exporter;
+sub inner {
+ my $pkg = caller();
+ our ( %INNER_BODY, %INNER_ARGS );
+
+ if ( my $body = $INNER_BODY{$pkg} ) {
+ my @args = @{ $INNER_ARGS{$pkg} };
+ local $INNER_ARGS{$pkg};
+ local $INNER_BODY{$pkg};
+ return $body->(@args);
+ } else {
+ return;
}
+}
+
+sub augment {
+ my $class = shift;
+ my ( $name, $method ) = @_;
+ $class->meta->add_augment_method_modifier( $name => $method );
+}
- sub unimport {
- no strict 'refs';
- my $class = _get_caller(@_);
+sub make_immutable {
+ my $class = shift;
+ cluck "The make_immutable keyword has been deprecated, " .
+ "please go back to __PACKAGE__->meta->make_immutable\n";
+ $class->meta->make_immutable(@_);
+}
+
+my $exporter = Moose::Exporter->build_import_methods(
+ with_caller => [
+ qw( extends with has before after around override augment make_immutable )
+ ],
+ as_is => [
+ qw( super inner ),
+ \&Carp::confess,
+ \&Scalar::Util::blessed,
+ ],
+);
+
+# This exists for backwards compat
+sub init_meta {
+ my ( $class, $base_class, $metaclass ) = @_;
+
+ __PACKAGE__->_init_meta( for_class => $class,
+ object_base_class => $base_class,
+ metaclass_class => $metaclass,
+ );
+}
- # loop through the exports ...
- foreach my $name ( keys %exports ) {
+sub _init_meta {
+ shift;
+ my %args = @_;
- # if we find one ...
- if ( defined &{ $class . '::' . $name } ) {
- my $keyword = \&{ $class . '::' . $name };
+ my $class = $args{for_class}
+ or confess "Cannot call _init_meta without specifying a for_class";
+ my $base_class = $args{object_base_class} || 'Moose::Object';
+ my $metaclass = $args{metaclass_class} || 'Moose::Meta::Class';
- # make sure it is from Moose
- my $pkg_name =
- eval { svref_2object($keyword)->GV->STASH->NAME };
- next if $@;
- next if $pkg_name ne 'Moose';
+ confess
+ "The Metaclass $metaclass must be a subclass of Moose::Meta::Class."
+ unless $metaclass->isa('Moose::Meta::Class');
- # and if it is from Moose then undef the slot
- delete ${ $class . '::' }{$name};
+ # make a subtype for each Moose class
+ class_type($class)
+ unless find_type_constraint($class);
+
+ my $meta;
+ if ( $class->can('meta') ) {
+ # NOTE:
+ # this is the case where the metaclass pragma
+ # was used before the 'use Moose' statement to
+ # override a specific class
+ $meta = $class->meta();
+ ( blessed($meta) && $meta->isa('Moose::Meta::Class') )
+ || confess "You already have a &meta function, but it does not return a Moose::Meta::Class";
+ }
+ else {
+ # NOTE:
+ # this is broken currently, we actually need
+ # to allow the possiblity of an inherited
+ # meta, which will not be visible until the
+ # user 'extends' first. This needs to have
+ # more intelligence to it
+ $meta = $metaclass->initialize($class);
+ $meta->add_method(
+ 'meta' => sub {
+ # re-initialize so it inherits properly
+ $metaclass->initialize( blessed( $_[0] ) || $_[0] );
}
- }
+ );
}
+ # make sure they inherit from Moose::Object
+ $meta->superclasses($base_class)
+ unless $meta->superclasses();
+
+ return $meta;
}
## make 'em all immutable
=head1 NAME
-Moose - A complete modern object system for Perl 5
+Moose - A postmodern object system for Perl 5
=head1 SYNOPSIS
package Point;
use Moose; # automatically turns on strict and warnings
-
+
has 'x' => (is => 'rw', isa => 'Int');
has 'y' => (is => 'rw', isa => 'Int');
-
+
sub clear {
my $self = shift;
$self->x(0);
- $self->y(0);
+ $self->y(0);
}
-
+
package Point3D;
use Moose;
-
+
extends 'Point';
-
+
has 'z' => (is => 'rw', isa => 'Int');
-
+
after 'clear' => sub {
my $self = shift;
$self->z(0);
- };
+ };
=head1 DESCRIPTION
-Moose is an extension of the Perl 5 object system.
+Moose is an extension of the Perl 5 object system.
-=head2 Another object system!?!?
+The main goal of Moose is to make Perl 5 Object Oriented programming
+easier, more consistent and less tedious. With Moose you can to think
+more about what you want to do and less about the mechanics of OOP.
-Yes, I know there has been an explosion recently of new ways to
-build object's in Perl 5, most of them based on inside-out objects
-and other such things. Moose is different because it is not a new
-object system for Perl 5, but instead an extension of the existing
-object system.
+Additionally, Moose is built on top of L<Class::MOP>, which is a
+metaclass system for Perl 5. This means that Moose not only makes
+building normal Perl 5 objects better, but it provides the power of
+metaclass programming as well.
-Moose is built on top of L<Class::MOP>, which is a metaclass system
-for Perl 5. This means that Moose not only makes building normal
-Perl 5 objects better, but it also provides the power of metaclass
-programming.
+=head2 Moose Extensions
-=head2 Is this for real? Or is this just an experiment?
-
-Moose is I<based> on the prototypes and experiments I did for the Perl 6
-meta-model. However, Moose is B<NOT> an experiment/prototype; it is for B<real>.
-
-=head2 Is this ready for use in production?
-
-Yes, I believe that it is.
-
-Moose has been used successfully in production environemnts by several people
-and companies (including the one I work for). There are Moose applications
-which have been in production with little or no issue now for over a year.
-I consider it highly stable and we are commited to keeping it stable.
-
-Of course, in the end, you need to make this call yourself. If you have
-any questions or concerns, please feel free to email me, or even the list
-or just stop by #moose and ask away.
-
-=head2 Is Moose just Perl 6 in Perl 5?
-
-No. While Moose is very much inspired by Perl 6, it is not itself Perl 6.
-Instead, it is an OO system for Perl 5. I built Moose because I was tired of
-writing the same old boring Perl 5 OO code, and drooling over Perl 6 OO. So
-instead of switching to Ruby, I wrote Moose :)
+The C<MooseX::> namespace is the official place to find Moose extensions.
+These extensions can be found on the CPAN. The easiest way to find them
+is to search for them (L<http://search.cpan.org/search?query=MooseX::>),
+or to examine L<Task::Moose> which aims to keep an up-to-date, easily
+installable list of Moose extensions.
=head1 BUILDING CLASSES WITH MOOSE
class construction/definition, but still stay out of your way if you want it
to. Here are a few items to note when building classes with Moose.
-Unless specified with C<extends>, any class which uses Moose will
+Unless specified with C<extends>, any class which uses Moose will
inherit from L<Moose::Object>.
Moose will also manage all attributes (including inherited ones) that are
setting defaults where appropriate, and performing any type constraint checking
or coercion.
-=head1 EXPORTED FUNCTIONS
+=head1 PROVIDED METHODS
-Moose will export a number of functions into the class's namespace which
-may then be used to set up the class. These functions all work directly
-on the current class.
+Moose provides a number of methods to all your classes, mostly through the
+inheritance of L<Moose::Object>. There is however, one exception.
=over 4
This is a method which provides access to the current class's metaclass.
+=back
+
+=head1 EXPORTED FUNCTIONS
+
+Moose will export a number of functions into the class's namespace which
+may then be used to set up the class. These functions all work directly
+on the current class.
+
+=over 4
+
=item B<extends (@superclasses)>
This function will set the superclass(es) for the current class.
-This approach is recommended instead of C<use base>, because C<use base>
-actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
-replace it. This is important to ensure that classes which do not have
+This approach is recommended instead of C<use base>, because C<use base>
+actually C<push>es onto the class's C<@ISA>, whereas C<extends> will
+replace it. This is important to ensure that classes which do not have
superclasses still properly inherit from L<Moose::Object>.
=item B<with (@roles)>
-This will apply a given set of C<@roles> to the local class. Role support
-is currently under heavy development; see L<Moose::Role> for more details.
+This will apply a given set of C<@roles> to the local class.
=item B<has $name =E<gt> %options>
-This will install an attribute of a given C<$name> into the current class.
-The C<%options> are the same as those provided by
-L<Class::MOP::Attribute>, in addition to the list below which are provided
+This will install an attribute of a given C<$name> into the current class.
+The C<%options> are the same as those provided by
+L<Class::MOP::Attribute>, in addition to the list below which are provided
by Moose (L<Moose::Meta::Attribute> to be more specific):
=over 4
=item I<is =E<gt> 'rw'|'ro'>
-The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
-only). These will create either a read/write accessor or a read-only
+The I<is> option accepts either I<rw> (for read/write) or I<ro> (for read
+only). These will create either a read/write accessor or a read-only
accessor respectively, using the same name as the C<$name> of the attribute.
If you need more control over how your accessors are named, you can use the
I<reader>, I<writer> and I<accessor> options inherited from
-L<Class::MOP::Attribute>.
+L<Class::MOP::Attribute>, however if you use those, you won't need the I<is>
+option.
=item I<isa =E<gt> $type_name>
-The I<isa> option uses Moose's type constraint facilities to set up runtime
-type checking for this attribute. Moose will perform the checks during class
-construction, and within any accessors. The C<$type_name> argument must be a
-string. The string may be either a class name or a type defined using
+The I<isa> option uses Moose's type constraint facilities to set up runtime
+type checking for this attribute. Moose will perform the checks during class
+construction, and within any accessors. The C<$type_name> argument must be a
+string. The string may be either a class name or a type defined using
Moose's type definition features. (Refer to L<Moose::Util::TypeConstraints>
for information on how to define a new type, and how to retrieve type meta-data).
=item I<coerce =E<gt> (1|0)>
-This will attempt to use coercion with the supplied type constraint to change
-the value passed into any accessors or constructors. You B<must> have supplied
-a type constraint in order for this to work. See L<Moose::Cookbook::Recipe5>
+This will attempt to use coercion with the supplied type constraint to change
+the value passed into any accessors or constructors. You B<must> have supplied
+a type constraint in order for this to work. See L<Moose::Cookbook::Basics::Recipe5>
for an example.
=item I<does =E<gt> $role_name>
-This will accept the name of a role which the value stored in this attribute
+This will accept the name of a role which the value stored in this attribute
is expected to have consumed.
=item I<required =E<gt> (1|0)>
-This marks the attribute as being required. This means a I<defined> value must be
-supplied during class construction, and the attribute may never be set to
-C<undef> with an accessor.
+This marks the attribute as being required. This means a I<defined> value must be
+supplied during class construction, and the attribute may never be set to
+C<undef> with an accessor.
=item I<weak_ref =E<gt> (1|0)>
=item I<lazy =E<gt> (1|0)>
-This will tell the class to not create this slot until absolutely necessary.
+This will tell the class to not create this slot until absolutely necessary.
If an attribute is marked as lazy it B<must> have a default supplied.
=item I<auto_deref =E<gt> (1|0)>
-This tells the accessor whether to automatically dereference the value returned.
+This tells the accessor whether to automatically dereference the value returned.
This is only legal if your C<isa> option is either C<ArrayRef> or C<HashRef>.
-=item I<metaclass =E<gt> $metaclass_name>
-
-This tells the class to use a custom attribute metaclass for this particular
-attribute. Custom attribute metaclasses are useful for extending the
-capabilities of the I<has> keyword: they are the simplest way to extend the MOP,
-but they are still a fairly advanced topic and too much to cover here. I will
-try and write a recipe on them soon.
-
-The default behavior here is to just load C<$metaclass_name>; however, we also
-have a way to alias to a shorter name. This will first look to see if
-B<Moose::Meta::Attribute::Custom::$metaclass_name> exists. If it does, Moose
-will then check to see if that has the method C<register_implemenetation>, which
-should return the actual name of the custom attribute metaclass. If there is no
-C<register_implemenetation> method, it will fall back to using
-B<Moose::Meta::Attribute::Custom::$metaclass_name> as the metaclass name.
-
=item I<trigger =E<gt> $code>
The I<trigger> option is a CODE reference which will be called after the value of
=item I<handles =E<gt> ARRAY | HASH | REGEXP | ROLE | CODE>
-The I<handles> option provides Moose classes with automated delegation features.
-This is a pretty complex and powerful option. It accepts many different option
-formats, each with its own benefits and drawbacks.
-
-B<NOTE:> This feature is no longer experimental, but it may still have subtle
-bugs lurking in the deeper corners. If you think you have found a bug, you
-probably have, so please report it to me right away.
+The I<handles> option provides Moose classes with automated delegation features.
+This is a pretty complex and powerful option. It accepts many different option
+formats, each with its own benefits and drawbacks.
B<NOTE:> The class being delegated to does not need to be a Moose based class,
which is why this feature is especially useful when wrapping non-Moose classes.
overriding locally defined methods, if you do want to do this, you should do it
manually, not with Moose.
+You do not I<need> to have a reader (or accessor) for the attribute in order
+to delegate to it. Moose will create a means of accessing the value for you,
+however this will be several times B<less> efficient then if you had given
+the attribute a reader (or accessor) to use.
+
Below is the documentation for each option format:
=over 4
=item C<ARRAY>
-This is the most common usage for I<handles>. You basically pass a list of
-method names to be delegated, and Moose will install a delegation method
+This is the most common usage for I<handles>. You basically pass a list of
+method names to be delegated, and Moose will install a delegation method
for each one.
=item C<HASH>
-This is the second most common usage for I<handles>. Instead of a list of
-method names, you pass a HASH ref where each key is the method name you
-want installed locally, and its value is the name of the original method
-in the class being delegated to.
+This is the second most common usage for I<handles>. Instead of a list of
+method names, you pass a HASH ref where each key is the method name you
+want installed locally, and its value is the name of the original method
+in the class being delegated to.
-This can be very useful for recursive classes like trees. Here is a
-quick example (soon to be expanded into a Moose::Cookbook::Recipe):
+This can be very useful for recursive classes like trees. Here is a
+quick example (soon to be expanded into a Moose::Cookbook recipe):
package Tree;
use Moose;
-
+
has 'node' => (is => 'rw', isa => 'Any');
-
+
has 'children' => (
is => 'ro',
isa => 'ArrayRef',
default => sub { [] }
);
-
+
has 'parent' => (
is => 'rw',
isa => 'Tree',
- is_weak_ref => 1,
+ weak_ref => 1,
handles => {
parent_node => 'node',
- siblings => 'children',
+ siblings => 'children',
}
);
In this example, the Tree package gets C<parent_node> and C<siblings> methods,
which delegate to the C<node> and C<children> methods (respectively) of the Tree
-instance stored in the C<parent> slot.
+instance stored in the C<parent> slot.
=item C<REGEXP>
-The regexp option works very similar to the ARRAY option, except that it builds
-the list of methods for you. It starts by collecting all possible methods of the
-class being delegated to, then filters that list using the regexp supplied here.
+The regexp option works very similar to the ARRAY option, except that it builds
+the list of methods for you. It starts by collecting all possible methods of the
+class being delegated to, then filters that list using the regexp supplied here.
-B<NOTE:> An I<isa> option is required when using the regexp option format. This
-is so that we can determine (at compile time) the method list from the class.
+B<NOTE:> An I<isa> option is required when using the regexp option format. This
+is so that we can determine (at compile time) the method list from the class.
Without an I<isa> this is just not possible.
=item C<ROLE>
-With the role option, you specify the name of a role whose "interface" then
-becomes the list of methods to handle. The "interface" can be defined as; the
-methods of the role and any required methods of the role. It should be noted
-that this does B<not> include any method modifiers or generated attribute
+With the role option, you specify the name of a role whose "interface" then
+becomes the list of methods to handle. The "interface" can be defined as; the
+methods of the role and any required methods of the role. It should be noted
+that this does B<not> include any method modifiers or generated attribute
methods (which is consistent with role composition).
=item C<CODE>
This takes a code reference, which should expect two arguments. The first is the
attribute meta-object this I<handles> is attached to. The second is the
metaclass of the class being delegated to. It expects you to return a hash (not
-a HASH ref) of the methods you want mapped.
+a HASH ref) of the methods you want mapped.
=back
+=item I<metaclass =E<gt> $metaclass_name>
+
+This tells the class to use a custom attribute metaclass for this particular
+attribute. Custom attribute metaclasses are useful for extending the
+capabilities of the I<has> keyword: they are the simplest way to extend the MOP,
+but they are still a fairly advanced topic and too much to cover here, see
+L<Moose::Cookbook::Meta::Recipe1> for more information.
+
+The default behavior here is to just load C<$metaclass_name>; however, we also
+have a way to alias to a shorter name. This will first look to see if
+B<Moose::Meta::Attribute::Custom::$metaclass_name> exists. If it does, Moose
+will then check to see if that has the method C<register_implementation>, which
+should return the actual name of the custom attribute metaclass. If there is no
+C<register_implementation> method, it will fall back to using
+B<Moose::Meta::Attribute::Custom::$metaclass_name> as the metaclass name.
+
+=item I<traits =E<gt> [ @role_names ]>
+
+This tells Moose to take the list of C<@role_names> and apply them to the
+attribute meta-object. This is very similar to the I<metaclass> option, but
+allows you to use more than one extension at a time. This too is an advanced
+topic, we don't yet have a cookbook for it though.
+
+As with I<metaclass>, the default behavior is to just load C<$role_name>; however,
+we also have a way to alias to a shorter name. This will first look to see if
+B<Moose::Meta::Attribute::Custom::Trait::$role_name> exists. If it does, Moose
+will then check to see if that has the method C<register_implementation>, which
+should return the actual name of the custom attribute trait. If there is no
+C<register_implementation> method, it will fall back to using
+B<Moose::Meta::Attribute::Custom::Trait::$metaclass_name> as the trait name.
+
=back
=item B<has +$name =E<gt> %options>
-This is variation on the normal attibute creator C<has> which allows you to
-clone and extend an attribute from a superclass. Here is a quick example:
+This is variation on the normal attibute creator C<has> which allows you to
+clone and extend an attribute from a superclass or from a role. Here is an
+example of the superclass usage:
package Foo;
use Moose;
-
+
has 'message' => (
- is => 'rw',
+ is => 'rw',
isa => 'Str',
default => 'Hello, I am a Foo'
);
-
+
package My::Foo;
use Moose;
-
+
extends 'Foo';
-
+
has '+message' => (default => 'Hello I am My::Foo');
What is happening here is that B<My::Foo> is cloning the C<message> attribute
from its parent class B<Foo>, retaining the C<is =E<gt> 'rw'> and C<isa =E<gt>
'Str'> characteristics, but changing the value in C<default>.
-This feature is restricted somewhat, so as to try and force at least I<some>
-sanity into it. You are only allowed to change the following attributes:
+Here is another example, but within the context of a role:
+
+ package Foo::Role;
+ use Moose::Role;
+
+ has 'message' => (
+ is => 'rw',
+ isa => 'Str',
+ default => 'Hello, I am a Foo'
+ );
+
+ package My::Foo;
+ use Moose;
+
+ with 'Foo::Role';
+
+ has '+message' => (default => 'Hello I am My::Foo');
+
+In this case, we are basically taking the attribute which the role supplied
+and altering it within the bounds of this feature.
+
+Aside from where the attributes come from (one from superclass, the other
+from a role), this feature works exactly the same. This feature is restricted
+somewhat, so as to try and force at least I<some> sanity into it. You are only
+allowed to change the following attributes:
=over 4
-=item I<default>
+=item I<default>
Change the default value of an attribute.
-=item I<coerce>
+=item I<coerce>
Change whether the attribute attempts to coerce a value passed to it.
-=item I<required>
+=item I<required>
Change if the attribute is required to have a value.
=item I<isa>
-You I<are> allowed to change the type, B<if and only if> the new type is a
-subtype of the old type.
+You I<are> allowed to change the type without restriction.
+
+It is recommended that you use this freedom with caution. We used to
+only allow for extension only if the type was a subtype of the parent's
+type, but we felt that was too restrictive and is better left as a
+policy descision.
=item I<handles>
-You are allowed to B<add> a new C<handles> definition, but you are B<not>
-allowed to I<change> one.
+You are allowed to B<add> a new C<handles> definition, but you are B<not>
+allowed to I<change> one.
+
+=item I<builder>
+
+You are allowed to B<add> a new C<builder> definition, but you are B<not>
+allowed to I<change> one.
+
+=item I<metaclass>
+
+You are allowed to B<add> a new C<metaclass> definition, but you are
+B<not> allowed to I<change> one.
+
+=item I<traits>
+
+You are allowed to B<add> additional traits to the C<traits> definition.
+These traits will be composed into the attribute, but pre-existing traits
+B<are not> overridden, or removed.
=back
=item B<super>
-The keyword C<super> is a no-op when called outside of an C<override> method. In
-the context of an C<override> method, it will call the next most appropriate
+The keyword C<super> is a no-op when called outside of an C<override> method. In
+the context of an C<override> method, it will call the next most appropriate
superclass method with the same arguments as the original method.
=item B<override ($name, &sub)>
-An C<override> method is a way of explicitly saying "I am overriding this
-method from my superclass". You can call C<super> within this method, and
-it will work as expected. The same thing I<can> be accomplished with a normal
-method call and the C<SUPER::> pseudo-package; it is really your choice.
+An C<override> method is a way of explicitly saying "I am overriding this
+method from my superclass". You can call C<super> within this method, and
+it will work as expected. The same thing I<can> be accomplished with a normal
+method call and the C<SUPER::> pseudo-package; it is really your choice.
=item B<inner>
-The keyword C<inner>, much like C<super>, is a no-op outside of the context of
-an C<augment> method. You can think of C<inner> as being the inverse of
+The keyword C<inner>, much like C<super>, is a no-op outside of the context of
+an C<augment> method. You can think of C<inner> as being the inverse of
C<super>; the details of how C<inner> and C<augment> work is best described in
-the L<Moose::Cookbook>.
+the L<Moose::Cookbook::Basics::Recipe6>.
=item B<augment ($name, &sub)>
-An C<augment> method, is a way of explicitly saying "I am augmenting this
-method from my superclass". Once again, the details of how C<inner> and
-C<augment> work is best described in the L<Moose::Cookbook>.
+An C<augment> method, is a way of explicitly saying "I am augmenting this
+method from my superclass". Once again, the details of how C<inner> and
+C<augment> work is best described in the L<Moose::Cookbook::Basics::Recipe6>.
=item B<confess>
This is the C<Carp::confess> function, and exported here because I use it
-all the time. This feature may change in the future, so you have been warned.
+all the time.
=item B<blessed>
This is the C<Scalar::Util::blessed> function, it is exported here because I
-use it all the time. It is highly recommended that this is used instead of
+use it all the time. It is highly recommended that this is used instead of
C<ref> anywhere you need to test for an object's class name.
=back
has 'first_name' => (is => 'rw', isa => 'Str');
has 'last_name' => (is => 'rw', isa => 'Str');
-
- sub full_name {
+
+ sub full_name {
my $self = shift;
- $self->first_name . ' ' . $self->last_name
+ $self->first_name . ' ' . $self->last_name
}
-
- no Moose; # keywords are removed from the Person package
+
+ no Moose; # keywords are removed from the Person package
=head1 EXTENDING AND EMBEDDING MOOSE
-Moose also offers some options for extending or embedding it into your own
+Moose also offers some options for extending or embedding it into your own
framework. The basic premise is to have something that sets up your class'
-metaclass and export the moose declarators (C<has>, C<with>, C<extends>,...).
+metaclass and export the moose declarators (C<has>, C<with>, C<extends>,...).
Here is an example:
package MyFramework;
use Moose;
-
+
sub import {
my $CALLER = caller();
Moose->import({into => $CALLER});
# Do my custom framework stuff
-
+
return 1;
}
-
+
=head2 B<import>
Moose's C<import> method supports the L<Sub::Exporter> form of C<{into =E<gt> $pkg}>
=head2 B<init_meta ($class, $baseclass, $metaclass)>
-Moose does some boot strapping: it creates a metaclass object for your class,
-and then injects a C<meta> accessor into your class to retrieve it. Then it
-sets your baseclass to Moose::Object or the value you pass in unless you already
-have one. This is all done via C<init_meta> which takes the name of your class
+Moose does some boot strapping: it creates a metaclass object for your class,
+and then injects a C<meta> accessor into your class to retrieve it. Then it
+sets your baseclass to Moose::Object or the value you pass in unless you already
+have one. This is all done via C<init_meta> which takes the name of your class
and optionally a baseclass and a metaclass as arguments.
-
+
+For more detail on this topic, see L<Moose::Cookbook::Extending::Recipe2>.
+
=head1 CAVEATS
=over 4
method. However, they may be combined within the same class hierarchy; see
F<t/014_override_augment_inner_super.t> for an example.
-The reason for this is that C<super> is only valid within a method
-with the C<override> modifier, and C<inner> will never be valid within an
-C<override> method. In fact, C<augment> will skip over any C<override> methods
+The reason for this is that C<super> is only valid within a method
+with the C<override> modifier, and C<inner> will never be valid within an
+C<override> method. In fact, C<augment> will skip over any C<override> methods
when searching for its appropriate C<inner>.
This might seem like a restriction, but I am of the opinion that keeping these
their behavior is then easier to predict. Time will tell whether I am right or
not (UPDATE: so far so good).
+=item *
+
+It is important to note that we currently have no simple way of combining
+multiple extended versions of Moose (see L<EXTENDING AND EMBEDDING MOOSE> above),
+and that in many cases they will conflict with one another. We are working on
+developing a way around this issue, but in the meantime, you have been warned.
+
+=back
+
+=head1 JUSTIFICATION
+
+In case you are still asking yourself "Why do I need this?", then this
+section is for you. This used to be part of the main DESCRIPTION, but
+I think Moose no longer actually needs justification, so it is included
+(read: buried) here for those who are still not convinced.
+
+=over 4
+
+=item Another object system!?!?
+
+Yes, I know there has been an explosion recently of new ways to
+build objects in Perl 5, most of them based on inside-out objects
+and other such things. Moose is different because it is not a new
+object system for Perl 5, but instead an extension of the existing
+object system.
+
+Moose is built on top of L<Class::MOP>, which is a metaclass system
+for Perl 5. This means that Moose not only makes building normal
+Perl 5 objects better, but it also provides the power of metaclass
+programming.
+
+=item Is this for real? Or is this just an experiment?
+
+Moose is I<based> on the prototypes and experiments I did for the Perl 6
+meta-model. However, Moose is B<NOT> an experiment/prototype; it is for B<real>.
+
+=item Is this ready for use in production?
+
+Yes, I believe that it is.
+
+Moose has been used successfully in production environemnts by several people
+and companies (including the one I work for). There are Moose applications
+which have been in production with little or no issue now for well over two years.
+I consider it highly stable and we are commited to keeping it stable.
+
+Of course, in the end, you need to make this call yourself. If you have
+any questions or concerns, please feel free to email me, or even the list
+or just stop by #moose and ask away.
+
+=item Is Moose just Perl 6 in Perl 5?
+
+No. While Moose is very much inspired by Perl 6, it is not itself Perl 6.
+Instead, it is an OO system for Perl 5. I built Moose because I was tired of
+writing the same old boring Perl 5 OO code, and drooling over Perl 6 OO. So
+instead of switching to Ruby, I wrote Moose :)
+
+=item Wait, I<post> modern, I thought it was just I<modern>?
+
+So I was reading Larry Wall's talk from the 1999 Linux World entitled
+"Perl, the first postmodern computer language" in which he talks about how
+he picked the features for Perl because he thought they were cool and he
+threw out the ones that he thought sucked. This got me thinking about how
+we have done the same thing in Moose. For Moose, we have "borrowed" features
+from Perl 6, CLOS (LISP), Smalltalk, Java, BETA, OCaml, Ruby and more, and
+the bits we didn't like (cause they sucked) we tossed aside. So for this
+reason (and a few others) I have re-dubbed Moose a I<postmodern> object system.
+
+Nuff Said.
+
=back
=head1 ACKNOWLEDGEMENTS
=item I blame Audrey Tang for then encouraging my meta-model habit in #perl6.
-=item Without Yuval "nothingmuch" Kogman this module would not be possible,
+=item Without Yuval "nothingmuch" Kogman this module would not be possible,
and it certainly wouldn't have this name ;P
-=item The basis of the TypeContraints module was Rob Kinyon's idea
+=item The basis of the TypeContraints module was Rob Kinyon's idea
originally, I just ran with it.
-=item Thanks to mst & chansen and the whole #moose poose for all the
+=item Thanks to mst & chansen and the whole #moose posse for all the
early ideas/feature-requests/encouragement/bug-finding.
=item Thanks to David "Theory" Wheeler for meta-discussions and spelling fixes.
=item L<http://www.iinteractive.com/moose>
This is the official web home of Moose, it contains links to our public SVN repo
-as well as links to a number of talks and articles on Moose and Moose related
-technologies.
+as well as links to a number of talks and articles on Moose and Moose related
+technologies.
+
+=item L<Moose::Cookbook> - How to cook a Moose
+
+=item The Moose is flying, a tutorial by Randal Schwartz
+
+Part 1 - L<http://www.stonehenge.com/merlyn/LinuxMag/col94.html>
+
+Part 2 - L<http://www.stonehenge.com/merlyn/LinuxMag/col95.html>
=item L<Class::MOP> documentation
=item The Moose mailing list - moose@perl.org
-=item Moose stats on ohloh.net - L<http://www.ohloh.net/projects/5788>
+=item Moose stats on ohloh.net - L<http://www.ohloh.net/projects/moose>
+
+=item Several Moose extension modules in the C<MooseX::> namespace.
+
+See L<http://search.cpan.org/search?query=MooseX::> for extensions.
=back
-=head2 Papers
+=head2 Books
+
+=over 4
+
+=item The Art of the MetaObject Protocol
+
+I mention this in the L<Class::MOP> docs too, this book was critical in
+the development of both modules and is highly recommended.
+
+=back
+
+=head2 Papers
=over 4
=item L<http://www.cs.utah.edu/plt/publications/oopsla04-gff.pdf>
-This paper (suggested by lbr on #moose) was what lead to the implementation
-of the C<super>/C<override> and C<inner>/C<augment> features. If you really
+This paper (suggested by lbr on #moose) was what lead to the implementation
+of the C<super>/C<override> and C<inner>/C<augment> features. If you really
want to understand them, I suggest you read this.
=back
=head1 BUGS
-All complex software has bugs lurking in it, and this module is no
+All complex software has bugs lurking in it, and this module is no
exception. If you find a bug please either email me, or add the bug
to cpan-RT.
+=head1 FEATURE REQUESTS
+
+We are very strict about what features we add to the Moose core, especially
+the user-visible features. Instead we have made sure that the underlying
+meta-system of Moose is as extensible as possible so that you can add your
+own features easily. That said, occasionally there is a feature needed in the
+meta-system to support your planned extension, in which case you should
+either email the mailing list or join us on irc at #moose to discuss.
+
=head1 AUTHOR
Stevan Little E<lt>stevan@iinteractive.comE<gt>
Chris (perigrin) Prather
+Wallace (wreis) Reis
+
Jonathan (jrockway) Rockway
Piotr (dexter) Roszatycki
-Sam (mugwump) Vilain
+Sam (mugwump) Vilain
+
+Shawn (sartak) Moore
... and many other #moose folks
=head1 COPYRIGHT AND LICENSE
-Copyright 2006, 2007 by Infinity Interactive, Inc.
+Copyright 2006-2008 by Infinity Interactive, Inc.
L<http://www.iinteractive.com>
This library is free software; you can redistribute it and/or modify
-it under the same terms as Perl itself.
+it under the same terms as Perl itself.
=cut
projects / gitmo/Moose.git / blobdiff