X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMoose%2FMeta%2FAttribute.pm;h=59ec38580f83c68ae94d5cfb8a0773faea996844;hb=9e4ed568f2e5c1041e6fea8d0cbde420562ab5df;hp=9be1657cd6cd3c513458cc52a90456ebed5f151b;hpb=1ed0b94f2778689bab78111b84efb26ae65c8eb2;p=gitmo%2FMoose.git diff --git a/lib/Moose/Meta/Attribute.pm b/lib/Moose/Meta/Attribute.pm index 9be1657..59ec385 100644 --- a/lib/Moose/Meta/Attribute.pm +++ b/lib/Moose/Meta/Attribute.pm @@ -4,14 +4,15 @@ package Moose::Meta::Attribute; use strict; use warnings; -use Scalar::Util 'blessed', 'weaken', 'reftype'; -use Carp 'confess'; +use Scalar::Util 'blessed', 'weaken'; use overload (); -our $VERSION = '0.13'; +our $VERSION = '0.84'; our $AUTHORITY = 'cpan:STEVAN'; use Moose::Meta::Method::Accessor; +use Moose::Meta::Method::Delegation; +use Moose::Util (); use Moose::Util::TypeConstraints (); use base 'Class::MOP::Attribute'; @@ -45,154 +46,347 @@ __PACKAGE__->meta->add_attribute('documentation' => ( reader => 'documentation', predicate => 'has_documentation', )); +__PACKAGE__->meta->add_attribute('traits' => ( + reader => 'applied_traits', + predicate => 'has_applied_traits', +)); + +# we need to have a ->does method in here to +# more easily support traits, and the introspection +# of those traits. We extend the does check to look +# for metatrait aliases. +sub does { + my ($self, $role_name) = @_; + my $name = eval { + Moose::Util::resolve_metatrait_alias(Attribute => $role_name) + }; + return 0 if !defined($name); # failed to load class + return $self->Moose::Object::does($name); +} + +sub throw_error { + my $self = shift; + my $class = ( ref $self && $self->associated_class ) || "Moose::Meta::Class"; + unshift @_, "message" if @_ % 2 == 1; + unshift @_, attr => $self if ref $self; + unshift @_, $class; + my $handler = $class->can("throw_error"); # to avoid incrementing depth by 1 + goto $handler; +} sub new { - my ($class, $name, %options) = @_; - $class->_process_options($name, \%options); - return $class->SUPER::new($name, %options); + my ($class, $name, %options) = @_; + $class->_process_options($name, \%options) unless $options{__hack_no_process_options}; # used from clone()... YECHKKK FIXME ICKY YUCK GROSS + + delete $options{__hack_no_process_options}; + + my %attrs = + ( map { $_ => 1 } + grep { defined } + map { $_->init_arg() } + $class->meta()->get_all_attributes() + ); + + my @bad = sort grep { ! $attrs{$_} } keys %options; + + if (@bad) + { + Carp::cluck "Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad"; + } + + return $class->SUPER::new($name, %options); +} + +sub interpolate_class_and_new { + my ($class, $name, %args) = @_; + + my ( $new_class, @traits ) = $class->interpolate_class(\%args); + + $new_class->new($name, %args, ( scalar(@traits) ? ( traits => \@traits ) : () ) ); +} + +sub interpolate_class { + my ($class, $options) = @_; + + $class = ref($class) || $class; + + if ( my $metaclass_name = delete $options->{metaclass} ) { + my $new_class = Moose::Util::resolve_metaclass_alias( Attribute => $metaclass_name ); + + if ( $class ne $new_class ) { + if ( $new_class->can("interpolate_class") ) { + return $new_class->interpolate_class($options); + } else { + $class = $new_class; + } + } + } + + my @traits; + + if (my $traits = $options->{traits}) { + my $i = 0; + while ($i < @$traits) { + my $trait = $traits->[$i++]; + next if ref($trait); # options to a trait we discarded + + $trait = Moose::Util::resolve_metatrait_alias(Attribute => $trait) + || $trait; + + next if $class->does($trait); + + push @traits, $trait; + + # are there options? + push @traits, $traits->[$i++] + if $traits->[$i] && ref($traits->[$i]); + } + + if (@traits) { + my $anon_class = Moose::Meta::Class->create_anon_class( + superclasses => [ $class ], + roles => [ @traits ], + cache => 1, + ); + + $class = $anon_class->name; + } + } + + return ( wantarray ? ( $class, @traits ) : $class ); } +# ... + +my @legal_options_for_inheritance = qw( + default coerce required + documentation lazy handles + builder type_constraint + definition_context + lazy_build +); + +sub legal_options_for_inheritance { @legal_options_for_inheritance } + +# NOTE/TODO +# This method *must* be able to handle +# Class::MOP::Attribute instances as +# well. Yes, I know that is wrong, but +# apparently we didn't realize it was +# doing that and now we have some code +# which is dependent on it. The real +# solution of course is to push this +# feature back up into Class::MOP::Attribute +# but I not right now, I am too lazy. +# However if you are reading this and +# looking for something to do,.. please +# be my guest. +# - stevan sub clone_and_inherit_options { my ($self, %options) = @_; - # you can change default, required, coerce, documentation and lazy + + my %copy = %options; + my %actual_options; - foreach my $legal_option (qw(default coerce required documentation lazy)) { + + # NOTE: + # we may want to extends a Class::MOP::Attribute + # in which case we need to be able to use the + # core set of legal options that have always + # been here. But we allows Moose::Meta::Attribute + # instances to changes them. + # - SL + my @legal_options = $self->can('legal_options_for_inheritance') + ? $self->legal_options_for_inheritance + : @legal_options_for_inheritance; + + foreach my $legal_option (@legal_options) { if (exists $options{$legal_option}) { $actual_options{$legal_option} = $options{$legal_option}; delete $options{$legal_option}; } } - # handles can only be added, not changed - if ($options{handles}) { - confess "You can only add the 'handles' option, you cannot change it" - if $self->has_handles; - $actual_options{handles} = $options{handles}; - delete $options{handles}; - } - - # isa can be changed, but only if the - # new type is a subtype if ($options{isa}) { my $type_constraint; - if (blessed($options{isa}) && $options{isa}->isa('Moose::Meta::TypeConstraint')) { - $type_constraint = $options{isa}; - } - else { - $type_constraint = Moose::Util::TypeConstraints::find_type_constraint($options{isa}); - (defined $type_constraint) - || confess "Could not find the type constraint '" . $options{isa} . "'"; - } - # NOTE: - # check here to see if the new type - # is a subtype of the old one - ($type_constraint->is_subtype_of($self->type_constraint->name)) - || confess "New type constraint setting must be a subtype of inherited one" - # iff we have a type constraint that is ... - if $self->has_type_constraint; - # then we use it :) - $actual_options{type_constraint} = $type_constraint; + if (blessed($options{isa}) && $options{isa}->isa('Moose::Meta::TypeConstraint')) { + $type_constraint = $options{isa}; + } + else { + $type_constraint = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa}); + (defined $type_constraint) + || $self->throw_error("Could not find the type constraint '" . $options{isa} . "'", data => $options{isa}); + } + + $actual_options{type_constraint} = $type_constraint; delete $options{isa}; } + + if ($options{does}) { + my $type_constraint; + if (blessed($options{does}) && $options{does}->isa('Moose::Meta::TypeConstraint')) { + $type_constraint = $options{does}; + } + else { + $type_constraint = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options{does}); + (defined $type_constraint) + || $self->throw_error("Could not find the type constraint '" . $options{does} . "'", data => $options{does}); + } + + $actual_options{type_constraint} = $type_constraint; + delete $options{does}; + } + + # NOTE: + # this doesn't apply to Class::MOP::Attributes, + # so we can ignore it for them. + # - SL + if ($self->can('interpolate_class')) { + ( $actual_options{metaclass}, my @traits ) = $self->interpolate_class(\%options); + + my %seen; + my @all_traits = grep { $seen{$_}++ } @{ $self->applied_traits || [] }, @traits; + $actual_options{traits} = \@all_traits if @all_traits; + + delete @options{qw(metaclass traits)}; + } + (scalar keys %options == 0) - || confess "Illegal inherited options => (" . (join ', ' => keys %options) . ")"; + || $self->throw_error("Illegal inherited options => (" . (join ', ' => keys %options) . ")", data => \%options); + + $self->clone(%actual_options); } +sub clone { + my ( $self, %params ) = @_; + + my $class = delete $params{metaclass} || ref $self; + + my ( @init, @non_init ); + + foreach my $attr ( grep { $_->has_value($self) } Class::MOP::class_of($self)->get_all_attributes ) { + push @{ $attr->has_init_arg ? \@init : \@non_init }, $attr; + } + + my %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params ); + + my $name = delete $new_params{name}; + + my $clone = $class->new($name, %new_params, __hack_no_process_options => 1 ); + + foreach my $attr ( @non_init ) { + $attr->set_value($clone, $attr->get_value($self)); + } + + return $clone; +} + sub _process_options { my ($class, $name, $options) = @_; - if (exists $options->{is}) { - if ($options->{is} eq 'ro') { - $options->{reader} ||= $name; - (!exists $options->{trigger}) - || confess "Cannot have a trigger on a read-only attribute"; - } - elsif ($options->{is} eq 'rw') { - $options->{accessor} = $name; - ((reftype($options->{trigger}) || '') eq 'CODE') - || confess "Trigger must be a CODE ref" - if exists $options->{trigger}; - } - else { - confess "I do not understand this option (is => " . $options->{is} . ")" - } - } + if (exists $options->{is}) { - if (exists $options->{isa}) { + ### ------------------------- + ## is => ro, writer => _foo # turns into (reader => foo, writer => _foo) as before + ## is => rw, writer => _foo # turns into (reader => foo, writer => _foo) + ## is => rw, accessor => _foo # turns into (accessor => _foo) + ## is => ro, accessor => _foo # error, accesor is rw + ### ------------------------- - if (exists $options->{does}) { - if (eval { $options->{isa}->can('does') }) { - ($options->{isa}->does($options->{does})) - || confess "Cannot have an isa option and a does option if the isa does not do the does"; - } - else { - confess "Cannot have an isa option which cannot ->does()"; - } + if ($options->{is} eq 'ro') { + $class->throw_error("Cannot define an accessor name on a read-only attribute, accessors are read/write", data => $options) + if exists $options->{accessor}; + $options->{reader} ||= $name; + } + elsif ($options->{is} eq 'rw') { + if ($options->{writer}) { + $options->{reader} ||= $name; + } + else { + $options->{accessor} ||= $name; } + } + elsif ($options->{is} eq 'bare') { + # do nothing, but don't complain (later) about missing methods + } + else { + $class->throw_error("I do not understand this option (is => " . $options->{is} . ") on attribute ($name)", data => $options->{is}); + } + } - # allow for anon-subtypes here ... - if (blessed($options->{isa}) && $options->{isa}->isa('Moose::Meta::TypeConstraint')) { - $options->{type_constraint} = $options->{isa}; - } - else { - $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_type_constraint( - $options->{isa} => { - parent => Moose::Util::TypeConstraints::find_type_constraint('Object'), - constraint => sub { $_[0]->isa($options->{isa}) } - } - ); - } + if (exists $options->{isa}) { + if (exists $options->{does}) { + if (eval { $options->{isa}->can('does') }) { + ($options->{isa}->does($options->{does})) + || $class->throw_error("Cannot have an isa option and a does option if the isa does not do the does on attribute ($name)", data => $options); + } + else { + $class->throw_error("Cannot have an isa option which cannot ->does() on attribute ($name)", data => $options); + } } - elsif (exists $options->{does}) { - # allow for anon-subtypes here ... - if (blessed($options->{does}) && $options->{does}->isa('Moose::Meta::TypeConstraint')) { - $options->{type_constraint} = $options->{isa}; - } - else { - $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_type_constraint( - $options->{does} => { - parent => Moose::Util::TypeConstraints::find_type_constraint('Role'), - constraint => sub { $_[0]->does($options->{does}) } - } - ); - } + + # allow for anon-subtypes here ... + if (blessed($options->{isa}) && $options->{isa}->isa('Moose::Meta::TypeConstraint')) { + $options->{type_constraint} = $options->{isa}; + } + else { + $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options->{isa}); + } + } + elsif (exists $options->{does}) { + # allow for anon-subtypes here ... + if (blessed($options->{does}) && $options->{does}->isa('Moose::Meta::TypeConstraint')) { + $options->{type_constraint} = $options->{does}; + } + else { + $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options->{does}); } + } - if (exists $options->{coerce} && $options->{coerce}) { - (exists $options->{type_constraint}) - || confess "You cannot have coercion without specifying a type constraint"; - confess "You cannot have a weak reference to a coerced value" + if (exists $options->{coerce} && $options->{coerce}) { + (exists $options->{type_constraint}) + || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)", data => $options); + $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)", data => $options) if $options->{weak_ref}; - } + } + + if (exists $options->{trigger}) { + ('CODE' eq ref $options->{trigger}) + || $class->throw_error("Trigger must be a CODE ref on attribute ($name)", data => $options->{trigger}); + } - if (exists $options->{auto_deref} && $options->{auto_deref}) { - (exists $options->{type_constraint}) - || confess "You cannot auto-dereference without specifying a type constraint"; - ($options->{type_constraint}->is_a_type_of('ArrayRef') || + if (exists $options->{auto_deref} && $options->{auto_deref}) { + (exists $options->{type_constraint}) + || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)", data => $options); + ($options->{type_constraint}->is_a_type_of('ArrayRef') || $options->{type_constraint}->is_a_type_of('HashRef')) - || confess "You cannot auto-dereference anything other than a ArrayRef or HashRef"; - } + || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)", data => $options); + } - if (exists $options->{lazy_build} && $options->{lazy_build} == 1) { - confess("You can not use lazy_build and default for the same attribute") - if exists $options->{default}; - $options->{lazy} = 1; - $options->{required} = 1; - $options->{builder} ||= "_build_${name}"; - if($name =~ /^_/){ - $options->{clearer} ||= "_clear${name}"; - $options->{predicate} ||= "_has${name}"; - } else { - $options->{clearer} ||= "clear_${name}"; - $options->{predicate} ||= "has_${name}"; - } + if (exists $options->{lazy_build} && $options->{lazy_build} == 1) { + $class->throw_error("You can not use lazy_build and default for the same attribute ($name)", data => $options) + if exists $options->{default}; + $options->{lazy} = 1; + $options->{builder} ||= "_build_${name}"; + if ($name =~ /^_/) { + $options->{clearer} ||= "_clear${name}"; + $options->{predicate} ||= "_has${name}"; } - - if (exists $options->{lazy} && $options->{lazy}) { - (exists $options->{default} || exists $options->{builder} ) - || confess "You cannot have lazy attribute without specifying a default value for it"; + else { + $options->{clearer} ||= "clear_${name}"; + $options->{predicate} ||= "has_${name}"; } + } + + if (exists $options->{lazy} && $options->{lazy}) { + (exists $options->{default} || defined $options->{builder} ) + || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it", data => $options); + } + + if ( $options->{required} && !( ( !exists $options->{init_arg} || defined $options->{init_arg} ) || exists $options->{default} || defined $options->{builder} ) ) { + $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg", data => $options); + } } @@ -203,7 +397,7 @@ sub initialize_instance_slot { my $val; my $value_is_set; - if (exists $params->{$init_arg}) { + if ( defined($init_arg) and exists $params->{$init_arg}) { $val = $params->{$init_arg}; $value_is_set = 1; } @@ -211,7 +405,7 @@ sub initialize_instance_slot { # skip it if it's lazy return if $self->is_lazy; # and die if it's required and doesn't have a default value - confess "Attribute (" . $self->name . ") is required" + $self->throw_error("Attribute (" . $self->name . ") is required", object => $instance, data => $params) if $self->is_required && !$self->has_default && !$self->has_builder; # if nothing was in the %params, we can use the @@ -219,76 +413,85 @@ sub initialize_instance_slot { if ($self->has_default) { $val = $self->default($instance); $value_is_set = 1; - } elsif ($self->has_builder) { - my $builder = $self->builder; - if($builder = $instance->can($builder)){ - $val = $instance->$builder; - $value_is_set = 1; - } else { - confess(blessed($instance)." does not support builder method '$builder' for attribute '" . $self->name . "'"); - } + } + elsif ($self->has_builder) { + $val = $self->_call_builder($instance); + $value_is_set = 1; } } return unless $value_is_set; - if ($self->has_type_constraint) { - my $type_constraint = $self->type_constraint; - if ($self->should_coerce && $type_constraint->has_coercion) { - $val = $type_constraint->coerce($val); - } - (defined($type_constraint->check($val))) - || confess "Attribute (" . - $self->name . - ") does not pass the type constraint (" . - $type_constraint->name . - ") with '" . - (defined $val - ? (blessed($val) && overload::Overloaded($val) - ? overload::StrVal($val) - : $val) - : 'undef') . - "'"; - } - - $meta_instance->set_slot_value($instance, $self->name, $val); + $val = $self->_coerce_and_verify( $val, $instance ); + + $self->set_initial_value($instance, $val); $meta_instance->weaken_slot_value($instance, $self->name) - if ref $val && $self->is_weak_ref; + if ref $val && $self->is_weak_ref; +} + +sub _call_builder { + my ( $self, $instance ) = @_; + + my $builder = $self->builder(); + + return $instance->$builder() + if $instance->can( $self->builder ); + + $self->throw_error( blessed($instance) + . " does not support builder method '" + . $self->builder + . "' for attribute '" + . $self->name + . "'", + object => $instance, + ); } ## Slot management -sub set_value { - my ($self, $instance, $value) = @_; +# FIXME: +# this duplicates too much code from +# Class::MOP::Attribute, we need to +# refactor these bits eventually. +# - SL +sub _set_initial_slot_value { + my ($self, $meta_instance, $instance, $value) = @_; - my $attr_name = $self->name; + my $slot_name = $self->name; - if ($self->is_required) { - defined($value) - || confess "Attribute ($attr_name) is required, so cannot be set to undef"; - } + return $meta_instance->set_slot_value($instance, $slot_name, $value) + unless $self->has_initializer; + my ($type_constraint, $can_coerce); if ($self->has_type_constraint) { + $type_constraint = $self->type_constraint; + $can_coerce = ($self->should_coerce && $type_constraint->has_coercion); + } - my $type_constraint = $self->type_constraint; + my $callback = sub { + my $val = $self->_coerce_and_verify( shift, $instance );; - if ($self->should_coerce) { - $value = $type_constraint->coerce($value); - } - defined($type_constraint->_compiled_type_constraint->($value)) - || confess "Attribute ($attr_name) does not pass the type constraint (" - . $type_constraint->name - . ") with " - . (defined($value) - ? ("'" . - (blessed($value) && overload::Overloaded($value) - ? overload::StrVal($value) - : $value) - . "'") - : "undef") - if defined($value); + $meta_instance->set_slot_value($instance, $slot_name, $val); + }; + + my $initializer = $self->initializer; + + # most things will just want to set a value, so make it first arg + $instance->$initializer($value, $callback, $self); +} + +sub set_value { + my ($self, $instance, @args) = @_; + my $value = $args[0]; + + my $attr_name = $self->name; + + if ($self->is_required and not @args) { + $self->throw_error("Attribute ($attr_name) is required", object => $instance); } + $value = $self->_coerce_and_verify( $value, $instance ); + my $meta_instance = Class::MOP::Class->initialize(blessed($instance)) ->get_meta_instance; @@ -299,7 +502,7 @@ sub set_value { } if ($self->has_trigger) { - $self->trigger->($instance, $value, $self); + $self->trigger->($instance, $value); } } @@ -307,22 +510,18 @@ sub get_value { my ($self, $instance) = @_; if ($self->is_lazy) { - unless ($self->has_value($instance)) { - if ($self->has_default) { - my $default = $self->default($instance); - $self->set_value($instance, $default); - } - if ( $self->has_builder ){ - my $builder = $self->builder; - if($builder = $instance->can($builder)){ - $self->set_value($instance, $instance->$builder); - } else { - confess(blessed($instance)." does not support builder method '$builder' for attribute '" . $self->name . "'"); - } - } else { - $self->set_value($instance, undef); - } + unless ($self->has_value($instance)) { + my $value; + if ($self->has_default) { + $value = $self->default($instance); + } elsif ( $self->has_builder ) { + $value = $self->_call_builder($instance); } + + $value = $self->_coerce_and_verify( $value, $instance ); + + $self->set_initial_value($instance, $value); + } } if ($self->should_auto_deref) { @@ -340,7 +539,7 @@ sub get_value { return wantarray ? %{ $rv } : $rv; } else { - confess "Can not auto de-reference the type constraint '" . $type_constraint->name . "'"; + $self->throw_error("Can not auto de-reference the type constraint '" . $type_constraint->name . "'", object => $instance, type_constraint => $type_constraint); } } @@ -357,58 +556,88 @@ sub accessor_metaclass { 'Moose::Meta::Method::Accessor' } sub install_accessors { my $self = shift; $self->SUPER::install_accessors(@_); + $self->install_delegation if $self->has_handles; + unless ( + @{ $self->associated_methods } + || ($self->_is_metadata || '') eq 'bare' + ) { + Carp::cluck( + 'Attribute (' . $self->name . ') has no associated methods' + . ' (did you mean to provide an "is" argument?)' + . "\n" + ) + } + return; +} - if ($self->has_handles) { +sub _process_accessors { + my $self = shift; + my ($type, $accessor, $generate_as_inline_methods) = @_; + $accessor = (keys %$accessor)[0] if (ref($accessor)||'') eq 'HASH'; + my $method = $self->associated_class->get_method($accessor); + if ($method && !$method->isa('Class::MOP::Method::Accessor') + && (!$self->definition_context + || $method->package_name eq $self->definition_context->{package})) { + Carp::cluck( + "You cannot overwrite a locally defined method ($accessor) with " + . "an accessor" + ); + } + $self->SUPER::_process_accessors(@_); +} - # NOTE: - # Here we canonicalize the 'handles' option - # this will sort out any details and always - # return an hash of methods which we want - # to delagate to, see that method for details - my %handles = $self->_canonicalize_handles(); - - # find the name of the accessor for this attribute - my $accessor_name = $self->reader || $self->accessor; - (defined $accessor_name) - || confess "You cannot install delegation without a reader or accessor for the attribute"; - - # make sure we handle HASH accessors correctly - ($accessor_name) = keys %{$accessor_name} - if ref($accessor_name) eq 'HASH'; - - # install the delegation ... - my $associated_class = $self->associated_class; - foreach my $handle (keys %handles) { - my $method_to_call = $handles{$handle}; +sub remove_accessors { + my $self = shift; + $self->SUPER::remove_accessors(@_); + $self->remove_delegation if $self->has_handles; + return; +} + +sub install_delegation { + my $self = shift; + + # NOTE: + # Here we canonicalize the 'handles' option + # this will sort out any details and always + # return an hash of methods which we want + # to delagate to, see that method for details + my %handles = $self->_canonicalize_handles; + + + # install the delegation ... + my $associated_class = $self->associated_class; + foreach my $handle (keys %handles) { + my $method_to_call = $handles{$handle}; + my $class_name = $associated_class->name; + my $name = "${class_name}::${handle}"; (!$associated_class->has_method($handle)) - || confess "You cannot overwrite a locally defined method ($handle) with a delegation"; + || $self->throw_error("You cannot overwrite a locally defined method ($handle) with a delegation", method_name => $handle); - # NOTE: - # handles is not allowed to delegate - # any of these methods, as they will - # override the ones in your class, which - # is almost certainly not what you want. - next if $handle =~ /^BUILD|DEMOLISH$/ || Moose::Object->can($handle); + # NOTE: + # handles is not allowed to delegate + # any of these methods, as they will + # override the ones in your class, which + # is almost certainly not what you want. - if ((reftype($method_to_call) || '') eq 'CODE') { - $associated_class->add_method($handle => $method_to_call); - } - else { - $associated_class->add_method($handle => sub { - # FIXME - # we should check for lack of - # a callable return value from - # the accessor here - my $proxy = (shift)->$accessor_name(); - @_ = ($proxy, @_); - goto &{ $proxy->can($method_to_call)}; - }); - } - } + # FIXME warn when $handle was explicitly specified, but not if the source is a regex or something + #cluck("Not delegating method '$handle' because it is a core method") and + next if $class_name->isa("Moose::Object") and $handle =~ /^BUILD|DEMOLISH$/ || Moose::Object->can($handle); + + my $method = $self->_make_delegation_method($handle, $method_to_call); + + $self->associated_class->add_method($method->name, $method); + $self->associate_method($method); } +} - return; +sub remove_delegation { + my $self = shift; + my %handles = $self->_canonicalize_handles; + my $associated_class = $self->associated_class; + foreach my $handle (keys %handles) { + $self->associated_class->remove_method($handle); + } } # private methods to help delegation ... @@ -425,29 +654,30 @@ sub _canonicalize_handles { } elsif ($handle_type eq 'Regexp') { ($self->has_type_constraint) - || confess "Cannot delegate methods based on a RegExpr without a type constraint (isa)"; + || $self->throw_error("Cannot delegate methods based on a Regexp without a type constraint (isa)", data => $handles); return map { ($_ => $_) } grep { /$handles/ } $self->_get_delegate_method_list; } elsif ($handle_type eq 'CODE') { return $handles->($self, $self->_find_delegate_metaclass); } + elsif (blessed($handles) && $handles->isa('Moose::Meta::TypeConstraint::DuckType')) { + return map { $_ => $_ } @{ $handles->methods }; + } else { - confess "Unable to canonicalize the 'handles' option with $handles"; + $self->throw_error("Unable to canonicalize the 'handles' option with $handles", data => $handles); } } else { - my $role_meta = eval { $handles->meta }; - if ($@) { - confess "Unable to canonicalize the 'handles' option with $handles because : $@"; - } + Class::MOP::load_class($handles); + my $role_meta = Class::MOP::class_of($handles); (blessed $role_meta && $role_meta->isa('Moose::Meta::Role')) - || confess "Unable to canonicalize the 'handles' option with $handles because ->meta is not a Moose::Meta::Role"; + || $self->throw_error("Unable to canonicalize the 'handles' option with $handles because its metaclass is not a Moose::Meta::Role", data => $handles); return map { $_ => $_ } ( $role_meta->get_method_list, - $role_meta->get_required_method_list + map { $_->name } $role_meta->get_required_method_list, ); } } @@ -455,22 +685,16 @@ sub _canonicalize_handles { sub _find_delegate_metaclass { my $self = shift; if (my $class = $self->_isa_metadata) { - # if the class does have - # a meta method, use it - return $class->meta if $class->can('meta'); - # otherwise we might be - # dealing with a non-Moose - # class, and need to make - # our own metaclass + # we might be dealing with a non-Moose class, + # and need to make our own metaclass. if there's + # already a metaclass, it will be returned return Moose::Meta::Class->initialize($class); } elsif (my $role = $self->_does_metadata) { - # our role will always have - # a meta method - return $role->meta; + return Class::MOP::class_of($role); } else { - confess "Cannot find delegate metaclass for attribute " . $self->name; + $self->throw_error("Cannot find delegate metaclass for attribute " . $self->name); } } @@ -478,18 +702,71 @@ sub _get_delegate_method_list { my $self = shift; my $meta = $self->_find_delegate_metaclass; if ($meta->isa('Class::MOP::Class')) { - return map { $_->{name} } # NOTE: !never! delegate &meta - grep { $_->{class} ne 'Moose::Object' && $_->{name} ne 'meta' } - $meta->compute_all_applicable_methods; + return map { $_->name } # NOTE: !never! delegate &meta + grep { $_->package_name ne 'Moose::Object' && $_->name ne 'meta' } + $meta->get_all_methods; } elsif ($meta->isa('Moose::Meta::Role')) { return $meta->get_method_list; } else { - confess "Unable to recognize the delegate metaclass '$meta'"; + $self->throw_error("Unable to recognize the delegate metaclass '$meta'", data => $meta); } } +sub delegation_metaclass { 'Moose::Meta::Method::Delegation' } + +sub _make_delegation_method { + my ( $self, $handle_name, $method_to_call ) = @_; + + my $method_body; + + $method_body = $method_to_call + if 'CODE' eq ref($method_to_call); + + return $self->delegation_metaclass->new( + name => $handle_name, + package_name => $self->associated_class->name, + attribute => $self, + delegate_to_method => $method_to_call, + ); +} + +sub _coerce_and_verify { + my $self = shift; + my $val = shift; + my $instance = shift; + + return $val unless $self->has_type_constraint; + + my $type_constraint = $self->type_constraint; + if ($self->should_coerce && $type_constraint->has_coercion) { + $val = $type_constraint->coerce($val); + } + + $self->verify_against_type_constraint($val, instance => $instance); + + return $val; +} + +sub verify_against_type_constraint { + my $self = shift; + my $val = shift; + + return 1 if !$self->has_type_constraint; + + my $type_constraint = $self->type_constraint; + + $type_constraint->check($val) + || $self->throw_error("Attribute (" + . $self->name + . ") does not pass the type constraint because: " + . $type_constraint->get_message($val), data => $val, @_); +} + +package Moose::Meta::Attribute::Custom::Moose; +sub register_implementation { 'Moose::Meta::Attribute' } + 1; __END__ @@ -502,162 +779,346 @@ Moose::Meta::Attribute - The Moose attribute metaclass =head1 DESCRIPTION -This is a subclass of L with Moose specific -extensions. +This class is a subclass of L that provides +additional Moose-specific functionality. + +To really understand this class, you will need to start with the +L documentation. This class can be understood +as a set of additional features on top of the basic feature provided +by that parent class. -For the most part, the only time you will ever encounter an -instance of this class is if you are doing some serious deep -introspection. To really understand this class, you need to refer -to the L documentation. +=head1 INHERITANCE + +C is a subclass of L. =head1 METHODS -=head2 Overridden methods +Many of the documented below override methods in +L and add Moose specific features. -These methods override methods in L and add -Moose specific features. You can safely assume though that they -will behave just as L does. +=head2 Creation =over 4 -=item B +=item B<< Moose::Meta::Attribute->new(%options) >> + +This method overrides the L constructor. + +Many of the options below are described in more detail in the +L document. + +It adds the following options to the constructor: + +=over 8 + +=item * is => 'ro', 'rw', 'bare' + +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. + +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. + +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. + +=item * isa => $type -=item B +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. -=item B +This option can also accept a L object. -=item B +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. + +=item * does => $role + +This is short-hand for saying that the attribute's type must be an +object which does the named role. + +=item * coerce => $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. + +You can make both this and the C option true. + +=item * trigger => $sub + +This option accepts a subroutine reference, which will be called after +the attribute is set. + +=item * required => $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. + +A required attribute must have a C, C or a +non-C C + +=item * lazy => $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. + +=item * weak_ref => $bool + +If this is true, the attribute's value will be stored as a weak +reference. + +=item * auto_deref => $bool + +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 * lazy_build => $bool + +Setting this to true makes the attribute lazy and provides a number of +default methods. + + has 'size' => ( + is => 'ro', + lazy_build => 1, + ); + +is equivalent to this: + + has 'size' => ( + is => 'ro', + lazy => 1, + builder => '_build_size', + clearer => 'clear_size', + predicate => 'has_size', + ); + +=item * documentation + +An arbitrary string that can be retrieved later by calling C<< +$attr->documentation >>. + +=back + +=item B<< $attr->clone(%options) >> + +This creates a new attribute based on attribute being cloned. You must +supply a C option to provide a new name for the attribute. + +The C<%options> can only specify options handled by +L. + +=back + +=head2 Value management + +=over 4 + +=item B<< $attr->initialize_instance_slot($meta_instance, $instance, $params) >> + +This method is used internally to initialize the attribute's slot in +the object C<$instance>. + +This overrides the L method to handle lazy +attributes, weak references, and type constraints. =item B =item B - eval { $point->meta->get_attribute('x')->set_value($point, 'fourty-two') }; + eval { $point->meta->get_attribute('x')->set_value($point, 'forty-two') }; if($@) { print "Oops: $@\n"; } -I +I Before setting the value, a check is made on the type constraint of the attribute, if it has one, to see if the value passes it. If the -value fails to pass, the set operation dies with a L. +value fails to pass, the set operation dies with a L. Any coercion to convert values is done before checking the type constraint. To check a value against a type constraint before setting it, fetch the -attribute instance using L, +attribute instance using L, fetch the type_constraint from the attribute using L -and call L. See L +and call L. See L for an example. =back +=head2 Attribute Accessor generation + +=over 4 + +=item B<< $attr->install_accessors >> + +This method overrides the parent to also install delegation methods. + +If, after installing all methods, the attribute object has no associated +methods, it throws an error unless C<< is => 'bare' >> was passed to the +attribute constructor. (Trying to add an attribute that has no associated +methods is almost always an error.) + +=item B<< $attr->remove_accessors >> + +This method overrides the parent to also remove delegation methods. + +=item B<< $attr->install_delegation >> + +This method adds its delegation methods to the attribute's associated +class, if it has any to add. + +=item B<< $attr->remove_delegation >> + +This method remove its delegation methods from the attribute's +associated class. + +=item B<< $attr->accessor_metaclass >> + +Returns the accessor metaclass name, which defaults to +L. + +=item B<< $attr->delegation_metaclass >> + +Returns the delegation metaclass name, which defaults to +L. + +=back + =head2 Additional Moose features -Moose attributes support type-constraint checking, weak reference -creation and type coercion. +These methods are not found in the superclass. They support features +provided by Moose. =over 4 -=item B +=item B<< $attr->does($role) >> + +This indicates whether the I does the given +role. The role can be given as a full class name, or as a resolvable +trait name. + +Note that this checks the attribute itself, not its type constraint, +so it is checking the attribute's metaclass and any traits applied to +the attribute. + +=item B<< Moose::Meta::Class->interpolate_class_and_new($name, %options) >> + +This is an alternate constructor that handles the C and +C options. + +Effectively, this method is a factory that finds or creates the +appropriate class for the given C and/or C. + +Once it has the appropriate class, it will call C<< $class->new($name, +%options) >> on that class. + +=item B<< $attr->clone_and_inherit_options(%options) >> + +This method supports the C feature. It does various bits +of processing on the supplied C<%options> before ultimately calling +the C method. + +One of its main tasks is to make sure that the C<%options> provided +only includes the options returned by the +C method. + +=item B<< $attr->legal_options_for_inheritance >> + +This returns a whitelist of options that can be overridden in a +subclass's attribute definition. -This is to support the C feature, it clones an attribute -from a superclass and allows a very specific set of changes to be made -to the attribute. +This exists to allow a custom metaclass to change or add to the list +of options which can be changed. -=item B +=item B<< $attr->type_constraint >> -Returns true if this meta-attribute has a type constraint. +Returns the L object for this attribute, +if it has one. -=item B +=item B<< $attr->has_type_constraint >> -A read-only accessor for this meta-attribute's type constraint. For -more information on what you can do with this, see the documentation -for L. +Returns true if this attribute has a type constraint. -=item B +=item B<< $attr->verify_against_type_constraint($value) >> -Returns true if this meta-attribute performs delegation. +Given a value, this method returns true if the value is valid for the +attribute's type constraint. If the value is not valid, it throws an +error. -=item B +=item B<< $attr->handles >> -This returns the value which was passed into the handles option. +This returns the value of the C option passed to the +constructor. -=item B +=item B<< $attr->has_handles >> -Returns true if this meta-attribute produces a weak reference. +Returns true if this attribute performs delegation. -=item B +=item B<< $attr->is_weak_ref >> -Returns true if this meta-attribute is required to have a value. +Returns true if this attribute stores its value as a weak reference. -=item B +=item B<< $attr->is_required >> -Returns true if this meta-attribute should be initialized lazily. +Returns true if this attribute is required to have a value. -NOTE: lazy attributes, B have a C or C field set. +=item B<< $attr->is_lazy >> -=item B +Returns true if this attribute is lazy. -Returns true if this meta-attribute should be initialized lazily through -the builder generated by lazy_build. Using C 1> will -make your attribute required and lazy. In addition it will set the builder, clearer -and predicate options for you using the following convention. +=item B<< $attr->is_lazy_build >> - #If your attribute name starts with an underscore: - has '_foo' => (lazy_build => 1); - #is the same as - has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', builder => '_build__foo); - # or - has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', default => sub{shift->_build__foo}); +Returns true if the C option was true when passed to the +constructor. - #If your attribute name does not start with an underscore: - has 'foo' => (lazy_build => 1); - #is the same as - has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', builder => '_build_foo); - # or - has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', default => sub{shift->_build_foo}); +=item B<< $attr->should_coerce >> -The reason for the different naming of the C is that the C -method is a private method while the C and C methods -are public methods. +Returns true if the C option passed to the constructor was +true. -NOTE: This means your class should provide a method whose name matches the value -of the builder part, in this case _build__foo or _build_foo. +=item B<< $attr->should_auto_deref >> -=item B +Returns true if the C option passed to the constructor was +true. -Returns true if this meta-attribute should perform type coercion. +=item B<< $attr->trigger >> -=item B +This is the subroutine reference that was in the C option +passed to the constructor, if any. -Returns true if this meta-attribute should perform automatic -auto-dereferencing. +=item B<< $attr->has_trigger >> -NOTE: This can only be done for attributes whose type constraint is -either I or I. +Returns true if this attribute has a trigger set. -=item B +=item B<< $attr->documentation >> -Returns true if this meta-attribute has a trigger set. +Returns the value that was in the C option passed to +the constructor, if any. -=item B +=item B<< $attr->has_documentation >> -This is a CODE reference which will be executed every time the -value of an attribute is assigned. The CODE ref will get two values, -the invocant and the new value. This can be used to handle I -bi-directional relations. +Returns true if this attribute has any documentation. -=item B +=item B<< $attr->applied_traits >> -This is a string which contains the documentation for this attribute. -It serves no direct purpose right now, but it might in the future -in some kind of automated documentation system perhaps. +This returns an array reference of all the traits which were applied +to this attribute. If none were applied, this returns C. -=item B +=item B<< $attr->has_applied_traits >> -Returns true if this meta-attribute has any documentation. +Returns true if this attribute has any traits applied. =back @@ -675,7 +1136,7 @@ Yuval Kogman Enothingmuch@woobling.comE =head1 COPYRIGHT AND LICENSE -Copyright 2006, 2007 by Infinity Interactive, Inc. +Copyright 2006-2009 by Infinity Interactive, Inc. L