X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=gitmo%2FMouse.git;a=blobdiff_plain;f=lib%2FMouse%2FMeta%2FAttribute.pm;h=eb3613f539207b07e053f1a2822c579167a7e1a1;hp=dec1a54e89b8d426a5f69000316ea480762d4f66;hb=d503a4f3aa9eda772309f6c99ccd4dfcdfed059d;hpb=2efc0af104c1926c066f50e1785236254bda12a2 diff --git a/lib/Mouse/Meta/Attribute.pm b/lib/Mouse/Meta/Attribute.pm index dec1a54..eb3613f 100644 --- a/lib/Mouse/Meta/Attribute.pm +++ b/lib/Mouse/Meta/Attribute.pm @@ -1,305 +1,228 @@ package Mouse::Meta::Attribute; -use strict; -use warnings; +use Mouse::Util qw(:meta); # enables strict and warnings use Carp (); -use Scalar::Util qw(weaken); - -use Mouse::Util; use Mouse::Meta::TypeConstraint; -use Mouse::Meta::Method::Accessor; - -#my %valid_attrs = map{ $_ => undef } qw( -# name -# reader writer accessor clearer predicate -# builder init_arg default initializer definition_context -# -# is -# isa does -# required -# lazy -# lazy_build -# coerce -# weak_ref -# auto_deref -# type_constraint -# trigger -# handles -# documentation -# traits -#); -sub new { - my ($class, $name, %options) = @_; +my %valid_options = map { $_ => undef } ( + 'accessor', + 'auto_deref', + 'builder', + 'clearer', + 'coerce', + 'default', + 'documentation', + 'does', + 'handles', + 'init_arg', + 'is', + 'isa', + 'lazy', + 'lazy_build', + 'name', + 'predicate', + 'reader', + 'required', + 'traits', + 'trigger', + 'type_constraint', + 'weak_ref', + 'writer', + + # internally used + 'associated_class', + 'associated_methods', + + # Moose defines, but Mouse doesn't + #'definition_context', + #'initializer', + #'insertion_order', + + # special case for AttributeHelpers + 'provides', + 'curries', +); - # taken from Class::MOP::Attribute::new +sub new { + my $class = shift; + my $name = shift; - defined($name) - or $class->throw_error('You must provide a name for the attribute'); - $options{name} = $name; + my $args = $class->Mouse::Object::BUILDARGS(@_); - if(!exists $options{init_arg}){ - $options{init_arg} = $name; + # XXX: for backward compatibility (with method modifiers) + if($class->can('canonicalize_args') != \&canonicalize_args){ + %{$args} = $class->canonicalize_args($name, %{$args}); } - # 'required' requires eigher 'init_arg', 'builder', or 'default' - my $can_be_required = defined( $options{init_arg} ); + $class->_process_options($name, $args); - if(exists $options{builder}){ - $class->throw_error('builder must be a defined scalar value which is a method name') - if ref $options{builder} || !(defined $options{builder}); + $args->{name} = $name; - $can_be_required++; - } - elsif(exists $options{default}){ - if(ref $options{default} && ref($options{default}) ne 'CODE'){ - $class->throw_error("References are not allowed as default values, you must " - . "wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])"); - } - $can_be_required++; - } + # check options + # (1) known by core + my @bad = grep{ !exists $valid_options{$_} } keys %{$args}; - if( $options{required} && !$can_be_required ) { - $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg"); + # (2) known by subclasses + if(@bad && $class ne __PACKAGE__){ + my %valid_attrs = ( + map { $_ => undef } + grep { defined } + map { $_->init_arg() } + $class->meta->get_all_attributes() + ); + @bad = grep{ !exists $valid_attrs{$_} } @bad; } - # taken from Mouse::Meta::Attribute->new and _process_options - - if(exists $options{is}){ - my $is = $options{is}; - - if($is eq 'ro'){ - $options{reader} ||= $name; - } - elsif($is eq 'rw'){ - if(exists $options{writer}){ - $options{reader} ||= $name; - } - else{ - $options{accessor} ||= $name; - } - } - elsif($is eq 'bare'){ - # do nothing, but don't complain (later) about missing methods - } - else{ - $is = 'undef' if !defined $is; - $class->throw_error("I do not understand this option (is => $is) on attribute ($name)"); - } + # (3) bad options found + if(@bad){ + @bad = sort @bad; + Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad"); } - my $tc; - if(exists $options{isa}){ - $options{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa}); - } - elsif(exists $options{does}){ - $options{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_does_type_constraint($options{does}); + my $self = bless $args, $class; + + # extra attributes + if($class ne __PACKAGE__){ + $class->meta->_initialize_object($self, $args); } - $tc = $options{type_constraint}; - if($options{coerce}){ - defined($tc) - || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)"); + return $self; +} - $options{weak_ref} - && $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)"); - } +sub has_read_method { $_[0]->has_reader || $_[0]->has_accessor } +sub has_write_method { $_[0]->has_writer || $_[0]->has_accessor } - if ($options{lazy_build}) { - exists($options{default}) - && $class->throw_error("You can not use lazy_build and default for the same attribute ($name)"); - - $options{lazy} = 1; - $options{builder} ||= "_build_${name}"; - if ($name =~ /^_/) { - $options{clearer} ||= "_clear${name}"; - $options{predicate} ||= "_has${name}"; - } - else { - $options{clearer} ||= "clear_${name}"; - $options{predicate} ||= "has_${name}"; - } - } +sub _create_args { # DEPRECATED + $_[0]->{_create_args} = $_[1] if @_ > 1; + $_[0]->{_create_args} +} - if ($options{auto_deref}) { - defined($tc) - || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)"); +sub interpolate_class{ + my($class, $args) = @_; - ( $tc->is_a_type_of('ArrayRef') || $tc->is_a_type_of('HashRef') ) - || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"); + if(my $metaclass = delete $args->{metaclass}){ + $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass ); } - if (exists $options{trigger}) { - ('CODE' eq ref $options{trigger}) - || $class->throw_error("Trigger must be a CODE ref on attribute ($name)"); - } + my @traits; + if(my $traits_ref = delete $args->{traits}){ - if ($options{lazy}) { - (exists $options{default} || defined $options{builder}) - || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it"); - } + for (my $i = 0; $i < @{$traits_ref}; $i++) { + my $trait = Mouse::Util::resolve_metaclass_alias(Attribute => $traits_ref->[$i], trait => 1); - if(my $metaclass = delete $options{metaclass}){ - $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass ); - } + next if $class->does($trait); + + push @traits, $trait; - if(my $traits_ref = delete $options{traits}){ - my @traits; - for (my $i = 9; $i < @{$traits_ref}; $i++) { - my $trait = Mouse::Util::resolve_metaclass_alias(Attribute => $traits_ref->[$i], trait => 1); - - next if $class->does($trait); - - push @traits, $trait; - - # are there options? - push @traits, $traits_ref->[++$i] - if ref($traits_ref->[$i+1]); + # are there options? + push @traits, $traits_ref->[++$i] + if ref($traits_ref->[$i+1]); } - if (@traits) { - $class = Mouse::Meta::Class->create_anon_class( - superclasses => [ $class ], - roles => [ @traits ], - cache => 1, - )->name; + if (@traits) { + $class = Mouse::Meta::Class->create_anon_class( + superclasses => [ $class ], + roles => \@traits, + cache => 1, + )->name; } } -# XXX: there is no fast way to check attribute validity -# my @bad = grep{ !exists $valid_attrs{$_} } keys %options; -# if(@bad){ -# @bad = sort @bad; -# Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad"); -# } - - return bless \%options, $class; + return( $class, @traits ); } -# readers - -sub name { $_[0]->{name} } -sub associated_class { $_[0]->{associated_class} } - -sub accessor { $_[0]->{accessor} } -sub reader { $_[0]->{reader} } -sub writer { $_[0]->{writer} } -sub predicate { $_[0]->{predicate} } -sub clearer { $_[0]->{clearer} } -sub handles { $_[0]->{handles} } - -sub _is_metadata { $_[0]->{is} } -sub is_required { $_[0]->{required} } -sub default { $_[0]->{default} } -sub is_lazy { $_[0]->{lazy} } -sub is_lazy_build { $_[0]->{lazy_build} } -sub is_weak_ref { $_[0]->{weak_ref} } -sub init_arg { $_[0]->{init_arg} } -sub type_constraint { $_[0]->{type_constraint} } - -sub trigger { $_[0]->{trigger} } -sub builder { $_[0]->{builder} } -sub should_auto_deref { $_[0]->{auto_deref} } -sub should_coerce { $_[0]->{coerce} } - -# predicates - -sub has_accessor { exists $_[0]->{accessor} } -sub has_reader { exists $_[0]->{reader} } -sub has_writer { exists $_[0]->{writer} } -sub has_predicate { exists $_[0]->{predicate} } -sub has_clearer { exists $_[0]->{clearer} } -sub has_handles { exists $_[0]->{handles} } - -sub has_default { exists $_[0]->{default} } -sub has_type_constraint { exists $_[0]->{type_constraint} } -sub has_trigger { exists $_[0]->{trigger} } -sub has_builder { exists $_[0]->{builder} } - -sub _create_args { - $_[0]->{_create_args} = $_[1] if @_ > 1; - $_[0]->{_create_args} -} +sub canonicalize_args{ # DEPRECATED + my ($self, $name, %args) = @_; -sub accessor_metaclass { 'Mouse::Meta::Method::Accessor' } + Carp::cluck("$self->canonicalize_args has been deprecated." + . "Use \$self->_process_options instead."); + + return %args; +} -sub create { +sub create { # DEPRECATED my ($self, $class, $name, %args) = @_; - my $attribute = $self->new($name, %args); + Carp::cluck("$self->create has been deprecated." + . "Use \$meta->add_attribute and \$attr->install_accessors instead."); - $attribute->_create_args(\%args); + # noop + return $self; +} - $class->add_attribute($attribute); - weaken($attribute->{associated_class} = $class); +sub _coerce_and_verify { + my($self, $value, $instance) = @_; - my $associated_methods = 0; + my $type_constraint = $self->{type_constraint}; + return $value if !defined $type_constraint; - my $generator_class = $self->accessor_metaclass; - foreach my $type(qw(accessor reader writer predicate clearer handles)){ - if(exists $attribute->{$type}){ - my $installer = '_install_' . $type; - $generator_class->$installer($attribute, $attribute->{$type}, $class); - $associated_methods++; - } + if ($self->should_coerce && $type_constraint->has_coercion) { + $value = $type_constraint->coerce($value); } - if($associated_methods == 0 && ($attribute->_is_metadata || '') ne 'bare'){ - Carp::cluck(qq{Attribute ($name) of class }.$class->name.qq{ has no associated methods (did you mean to provide an "is" argument?)}); - - } + $self->verify_against_type_constraint($value); - return $attribute; + return $value; } sub verify_against_type_constraint { my ($self, $value) = @_; - my $tc = $self->type_constraint; - return 1 unless $tc; - local $_ = $value; - return 1 if $tc->check($value); + my $type_constraint = $self->{type_constraint}; + return 1 if !$type_constraint; + return 1 if $type_constraint->check($value); - $self->verify_type_constraint_error($self->name, $value, $tc); + $self->_throw_type_constraint_error($value, $type_constraint); } -sub verify_type_constraint_error { - my($self, $name, $value, $type) = @_; - $self->throw_error("Attribute ($name) does not pass the type constraint because: " . $type->get_message($value)); -} +sub _throw_type_constraint_error { + my($self, $value, $type) = @_; -sub coerce_constraint { ## my($self, $value) = @_; - my $type = $_[0]->{type_constraint} - or return $_[1]; - return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $_[0]->type_constraint, $_[1]); + $self->throw_error( + sprintf q{Attribute (%s) does not pass the type constraint because: %s}, + $self->name, + $type->get_message($value), + ); } -sub _canonicalize_handles { - my $self = shift; - my $handles = shift; +sub clone_and_inherit_options{ + my $self = shift; + my $args = $self->Mouse::Object::BUILDARGS(@_); - if (ref($handles) eq 'HASH') { - return %$handles; - } - elsif (ref($handles) eq 'ARRAY') { - return map { $_ => $_ } @$handles; + my($attribute_class, @traits) = ref($self)->interpolate_class($args); + + $args->{traits} = \@traits if @traits; + # do not inherit the 'handles' attribute + foreach my $name(keys %{$self}){ + if(!exists $args->{$name} && $name ne 'handles'){ + $args->{$name} = $self->{$name}; + } } - else { - $self->throw_error("Unable to canonicalize the 'handles' option with $handles"); + + # remove temporary caches + foreach my $attr(keys %{$args}){ + if($attr =~ /\A _/xms){ + delete $args->{$attr}; + } } + + return $attribute_class->new($self->name, $args); } -sub clone_parent { +sub clone_parent { # DEPRECATED my $self = shift; my $class = shift; my $name = shift; my %args = ($self->get_parent_args($class, $name), @_); - $self->create($class, $name, %args); + Carp::cluck("$self->clone_parent has been deprecated." + . "Use \$meta->add_attribute and \$attr->install_accessors instead."); + + $self->clone_and_inherited_args($class, $name, %args); } -sub get_parent_args { +sub get_parent_args { # DEPRECATED my $self = shift; my $class = shift; my $name = shift; @@ -313,6 +236,154 @@ sub get_parent_args { $self->throw_error("Could not find an attribute by the name of '$name' to inherit from"); } + +sub get_read_method { + return $_[0]->reader || $_[0]->accessor +} +sub get_write_method { + return $_[0]->writer || $_[0]->accessor +} + +sub _get_accessor_method_ref { + my($self, $type, $generator) = @_; + + my $metaclass = $self->associated_class + || $self->throw_error('No asocciated class for ' . $self->name); + + my $accessor = $self->$type(); + if($accessor){ + return $metaclass->get_method_body($accessor); + } + else{ + return $self->accessor_metaclass->$generator($self, $metaclass); + } +} + +sub get_read_method_ref{ + my($self) = @_; + return $self->{_read_method_ref} ||= $self->_get_accessor_method_ref('get_read_method', '_generate_reader'); +} + +sub get_write_method_ref{ + my($self) = @_; + return $self->{_write_method_ref} ||= $self->_get_accessor_method_ref('get_write_method', '_generate_writer'); +} + +sub set_value { + my($self, $object, $value) = @_; + return $self->get_write_method_ref()->($object, $value); +} + +sub get_value { + my($self, $object) = @_; + return $self->get_read_method_ref()->($object); +} + +sub has_value { + my($self, $object) = @_; + my $accessor_ref = $self->{_predicate_ref} + ||= $self->_get_accessor_method_ref('predicate', '_generate_predicate'); + + return $accessor_ref->($object); +} + +sub clear_value { + my($self, $object) = @_; + my $accessor_ref = $self->{_crealer_ref} + ||= $self->_get_accessor_method_ref('clearer', '_generate_clearer'); + + return $accessor_ref->($object); +} + + +sub associate_method{ + my ($attribute, $method_name) = @_; + $attribute->{associated_methods}++; + return; +} + +sub install_accessors{ + my($attribute) = @_; + + my $metaclass = $attribute->associated_class; + my $accessor_class = $attribute->accessor_metaclass; + + foreach my $type(qw(accessor reader writer predicate clearer)){ + if(exists $attribute->{$type}){ + my $generator = '_generate_' . $type; + my $code = $accessor_class->$generator($attribute, $metaclass); + $metaclass->add_method($attribute->{$type} => $code); + $attribute->associate_method($attribute->{$type}); + } + } + + # install delegation + if(exists $attribute->{handles}){ + my %handles = $attribute->_canonicalize_handles($attribute->{handles}); + + while(my($handle, $method_to_call) = each %handles){ + $metaclass->add_method($handle => + $attribute->_make_delegation_method( + $handle, $method_to_call)); + + $attribute->associate_method($handle); + } + } + + if($attribute->can('create') != \&create){ + # backword compatibility + $attribute->create($metaclass, $attribute->name, %{$attribute}); + } + + if(!$attribute->{associated_methods} && ($attribute->{is} || '') ne 'bare'){ + Carp::cluck( + 'Attribute (' . $attribute->name . ') of class ' . $metaclass->name + . ' has no associated methods (did you mean to provide an "is" argument?)'); + } + + return; +} + +sub delegation_metaclass() { 'Mouse::Meta::Method::Delegation' } + +sub _canonicalize_handles { + my($self, $handles) = @_; + + if (ref($handles) eq 'HASH') { + return %$handles; + } + elsif (ref($handles) eq 'ARRAY') { + return map { $_ => $_ } @$handles; + } + elsif ( ref($handles) eq 'CODE' ) { + my $class_or_role = ( $self->{isa} || $self->{does} ) + || $self->throw_error( "Cannot find delegate metaclass for attribute " . $self->name ); + return $handles->( $self, Mouse::Meta::Class->initialize("$class_or_role")); + } + elsif (ref($handles) eq 'Regexp') { + my $class_or_role = ($self->{isa} || $self->{does}) + || $self->throw_error("Cannot delegate methods based on a Regexp without a type constraint (isa)"); + + my $meta = Mouse::Meta::Class->initialize("$class_or_role"); # "" for stringify + return map { $_ => $_ } + grep { !Mouse::Object->can($_) && $_ =~ $handles } + Mouse::Util::is_a_metarole($meta) + ? $meta->get_method_list + : $meta->get_all_method_names; + } + else { + $self->throw_error("Unable to canonicalize the 'handles' option with $handles"); + } +} + +sub _make_delegation_method { + my($self, $handle, $method_to_call) = @_; + my $delegator = $self->delegation_metaclass; + Mouse::Util::load_class($delegator); + + return $delegator->_generate_delegation($self, $handle, $method_to_call); +} + sub throw_error{ my $self = shift; @@ -321,95 +392,153 @@ sub throw_error{ } 1; - __END__ =head1 NAME -Mouse::Meta::Attribute - attribute metaclass +Mouse::Meta::Attribute - The Mouse attribute metaclass + +=head1 VERSION + +This document describes Mouse version 0.50_02 =head1 METHODS -=head2 new %args -> Mouse::Meta::Attribute +=head2 C<< new(%options) -> Mouse::Meta::Attribute >> Instantiates a new Mouse::Meta::Attribute. Does nothing else. -=head2 create OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute +It adds the following options to the constructor: -Creates a new attribute in OwnerClass. Accessors and helper methods are -installed. Some error checking is done. +=over 4 -=head2 name -> AttributeName +=item C<< is => 'ro', 'rw', 'bare' >> -=head2 associated_class -> OwnerClass +This provides a shorthand for specifying the C, C, or +C names. If the attribute is read-only ('ro') then it will +have a C method with the same attribute as the name. -=head2 is_required -> Bool +If it is read-write ('rw') then it will have an C method +with the same name. If you provide an explicit C for a +read-write attribute, then you will have a C with the same +name as the attribute, and a C with the name you provided. -=head2 default -> Item +Use 'bare' when you are deliberately not installing any methods +(accessor, reader, etc.) associated with this attribute; otherwise, +Moose will issue a deprecation warning when this attribute is added to a +metaclass. -=head2 has_default -> Bool +=item C<< isa => Type >> -=head2 is_lazy -> Bool +This option accepts a type. The type can be a string, which should be +a type name. If the type name is unknown, it is assumed to be a class +name. -=head2 predicate -> MethodName | Undef +This option can also accept a L object. -=head2 has_predicate -> Bool +If you I provide a C option, then your C option must +be a class name, and that class must do the role specified with +C. -=head2 clearer -> MethodName | Undef +=item C<< does => Role >> -=head2 has_clearer -> Bool +This is short-hand for saying that the attribute's type must be an +object which does the named role. -=head2 handles -> { LocalName => RemoteName } +B -=head2 has_handles -> Bool +=item C<< coerce => Bool >> -=head2 is_weak_ref -> Bool +This option is only valid for objects with a type constraint +(C). If this is true, then coercions will be applied whenever +this attribute is set. -=head2 init_arg -> Str +You can make both this and the C option true. -=head2 type_constraint -> Str +=item C<< trigger => CodeRef >> -=head2 has_type_constraint -> Bool +This option accepts a subroutine reference, which will be called after +the attribute is set. -=head2 trigger => CODE | Undef +=item C<< required => Bool >> -=head2 has_trigger -> Bool +An attribute which is required must be provided to the constructor. An +attribute which is required can also have a C or C, +which will satisfy its required-ness. -=head2 builder => MethodName | Undef +A required attribute must have a C, C or a +non-C C -=head2 has_builder -> Bool +=item C<< lazy => Bool >> -=head2 is_lazy_build => Bool +A lazy attribute must have a C or C. When an +attribute is lazy, the default value will not be calculated until the +attribute is read. -=head2 should_auto_deref -> Bool +=item C<< weak_ref => Bool >> -Informational methods. +If this is true, the attribute's value will be stored as a weak +reference. -=head2 verify_against_type_constraint Item -> 1 | ERROR +=item C<< auto_deref => Bool >> -Checks that the given value passes this attribute's type constraint. Returns 1 -on success, otherwise Ces. +If this is true, then the reader will dereference the value when it is +called. The attribute must have a type constraint which defines the +attribute as an array or hash reference. + +=item C<< lazy_build => Bool >> + +Setting this to true makes the attribute lazy and provides a number of +default methods. + + has 'size' => ( + is => 'ro', + lazy_build => 1, + ); + +is equivalent to this: -=head2 canonicalize_args Name, %args -> %args + has 'size' => ( + is => 'ro', + lazy => 1, + builder => '_build_size', + clearer => 'clear_size', + predicate => 'has_size', + ); -Canonicalizes some arguments to create. In particular, C is -canonicalized into C, C, etc. +=back -=head2 validate_args Name, \%args -> 1 | ERROR +=head2 C<< associate_method(MethodName) >> -Checks that the arguments to create the attribute (ie those specified by -C) are valid. +Associates a method with the attribute. Typically, this is called internally +when an attribute generates its accessors. -=head2 clone_parent OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute +Currently the argument I is ignored in Mouse. -Creates a new attribute in OwnerClass, inheriting options from parent classes. +=head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >> + +Checks that the given value passes this attribute's type constraint. Returns C +on success, otherwise Ces. + +=head2 C<< clone_and_inherit_options(options) -> Mouse::Meta::Attribute >> + +Creates a new attribute in the owner class, inheriting options from parent classes. Accessors and helper methods are installed. Some error checking is done. -=head2 get_parent_args OwnerClass, AttributeName -> Hash +=head2 C<< get_read_method_ref >> + +=head2 C<< get_write_method_ref >> + +Returns the subroutine reference of a method suitable for reading or +writing the attribute's value in the associated class. These methods +always return a subroutine reference, regardless of whether or not the +attribute is read- or write-only. + +=head1 SEE ALSO + +L -Returns the options that the parent class of C used for attribute -C. +L =cut - \ No newline at end of file