X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMoose%2FMeta%2FAttribute.pm;h=8ca92ccfeef10cfaf9cf23a72f509ea51181c678;hb=dbe21639d532a07229d0beeffafafba66a7e26f5;hp=878f8cd54a1a988d95c6d647b79f128725668cab;hpb=431238198700daaa9506a6fff3f0fe48d15d1717;p=gitmo%2FMoose.git diff --git a/lib/Moose/Meta/Attribute.pm b/lib/Moose/Meta/Attribute.pm index 878f8cd..8ca92cc 100644 --- a/lib/Moose/Meta/Attribute.pm +++ b/lib/Moose/Meta/Attribute.pm @@ -4,11 +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 = '0.08'; +our $VERSION = '0.79'; +our $AUTHORITY = 'cpan:STEVAN'; +use Moose::Meta::Method::Accessor; +use Moose::Meta::Method::Delegation; +use Moose::Util (); use Moose::Util::TypeConstraints (); use base 'Class::MOP::Attribute'; @@ -22,6 +26,7 @@ __PACKAGE__->meta->add_attribute('is' => (reader => '_is_metadata')); # these are actual options for the attrs __PACKAGE__->meta->add_attribute('required' => (reader => 'is_required' )); __PACKAGE__->meta->add_attribute('lazy' => (reader => 'is_lazy' )); +__PACKAGE__->meta->add_attribute('lazy_build' => (reader => 'is_lazy_build' )); __PACKAGE__->meta->add_attribute('coerce' => (reader => 'should_coerce' )); __PACKAGE__->meta->add_attribute('weak_ref' => (reader => 'is_weak_ref' )); __PACKAGE__->meta->add_attribute('auto_deref' => (reader => 'should_auto_deref')); @@ -37,151 +42,333 @@ __PACKAGE__->meta->add_attribute('handles' => ( reader => 'handles', predicate => 'has_handles', )); +__PACKAGE__->meta->add_attribute('documentation' => ( + reader => 'documentation', + predicate => 'has_documentation', +)); +__PACKAGE__->meta->add_attribute('traits' => ( + reader => 'applied_traits', + predicate => 'has_applied_traits', +)); + +# we need to have a ->does method in here to +# more easily support traits, and the introspection +# of those traits. We extend the does check to look +# for metatrait aliases. +sub does { + my ($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 + 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 and coerce + + my %copy = %options; + my %actual_options; - foreach my $legal_option (qw(default coerce required)) { + + # 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}; } } - # 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 $options{isa}; } - (scalar keys %options == 0) - || confess "Illegal inherited options => (" . (join ', ' => keys %options) . ")"; + + if ($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) + || $self->throw_error("Illegal inherited options => (" . (join ', ' => keys %options) . ")", data => \%options); + + $self->clone(%actual_options); } +sub clone { + my ( $self, %params ) = @_; + + my $class = $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->{isa}) { - - if (exists $options->{does}) { - if (eval { $options->{isa}->can('does') }) { - ($options->{isa}->does($options->{does})) - || confess "Cannot have an isa option and a does option if the isa does not do the does"; - } - else { - confess "Cannot have an isa option which cannot ->does()"; - } - } - - # allow for anon-subtypes here ... - if (blessed($options->{isa}) && $options->{isa}->isa('Moose::Meta::TypeConstraint')) { - $options->{type_constraint} = $options->{isa}; - } - else { - - if ($options->{isa} =~ /\|/) { - my @type_constraints = split /\s*\|\s*/ => $options->{isa}; - $options->{type_constraint} = Moose::Util::TypeConstraints::create_type_constraint_union( - @type_constraints - ); - } - else { - # otherwise assume it is a constraint - my $constraint = Moose::Util::TypeConstraints::find_type_constraint($options->{isa}); - # if the constraing it not found .... - unless (defined $constraint) { - # assume it is a foreign class, and make - # an anon constraint for it - $constraint = Moose::Util::TypeConstraints::subtype( - 'Object', - Moose::Util::TypeConstraints::where { $_->isa($options->{isa}) } - ); - } - $options->{type_constraint} = $constraint; + + if (exists $options->{is}) { + + ### ------------------------- + ## is => ro, writer => _foo # turns into (reader => foo, writer => _foo) as before + ## is => rw, writer => _foo # turns into (reader => foo, writer => _foo) + ## is => rw, accessor => _foo # turns into (accessor => _foo) + ## is => ro, accessor => _foo # error, accesor is rw + ### ------------------------- + + if ($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; + } + } + else { + $class->throw_error("I do not understand this option (is => " . $options->{is} . ") on attribute ($name)", data => $options->{is}); + } + } + + 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); } - } - } - 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 { - # otherwise assume it is a constraint - my $constraint = Moose::Util::TypeConstraints::find_type_constraint($options->{does}); - # if the constraing it not found .... - unless (defined $constraint) { - # assume it is a foreign class, and make - # an anon constraint for it - $constraint = Moose::Util::TypeConstraints::subtype( - 'Role', - Moose::Util::TypeConstraints::where { $_->does($options->{does}) } - ); - } - $options->{type_constraint} = $constraint; - } - } - - 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 $options->{weak_ref}; - } - - 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') || + else { + $class->throw_error("Cannot have an isa option which cannot ->does() on attribute ($name)", data => $options); + } + } + + # allow for anon-subtypes here ... + if (blessed($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}) + || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($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}) + || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($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"; - } - - if (exists $options->{lazy} && $options->{lazy}) { - (exists $options->{default}) - || confess "You cannot have lazy attribute without specifying a default value for it"; - } + || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)", data => $options); + } + + if (exists $options->{lazy_build} && $options->{lazy_build} == 1) { + $class->throw_error("You can not use lazy_build and default for the same attribute ($name)", data => $options) + if exists $options->{default}; + $options->{lazy} = 1; + $options->{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} && $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); + } + } sub initialize_instance_slot { @@ -189,255 +376,222 @@ sub initialize_instance_slot { my $init_arg = $self->init_arg(); # try to fetch the init arg from the %params ... - my $val; - if (exists $params->{$init_arg}) { + my $val; + my $value_is_set; + if ( defined($init_arg) and exists $params->{$init_arg}) { $val = $params->{$init_arg}; + $value_is_set = 1; } else { # 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" - if $self->is_required && !$self->has_default; - } - - # if nothing was in the %params, we can use the - # attribute's default value (if it has one) - if (!defined $val && $self->has_default) { - $val = $self->default($instance); - } - if (defined $val) { - if ($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 (" . - $type_constraint->name . - ") with '$val'"; + $self->throw_error("Attribute (" . $self->name . ") is required", object => $instance, data => $params) + if $self->is_required && !$self->has_default && !$self->has_builder; + + # if nothing was in the %params, we can use the + # attribute's default value (if it has one) + if ($self->has_default) { + $val = $self->default($instance); + $value_is_set = 1; + } + elsif ($self->has_builder) { + $val = $self->_call_builder($instance); + $value_is_set = 1; } - } + } + + return unless $value_is_set; - $meta_instance->set_slot_value($instance, $self->name, $val); - $meta_instance->weaken_slot_value($instance, $self->name) + $val = $self->_coerce_and_verify( $val, $instance ); + + $self->set_initial_value($instance, $val); + $meta_instance->weaken_slot_value($instance, $self->name) if ref $val && $self->is_weak_ref; } -## Accessor inline subroutines - -sub _inline_check_constraint { - my ($self, $value) = @_; - return '' unless $self->has_type_constraint; - - # FIXME - remove 'unless defined($value) - constraint Undef - return sprintf <<'EOF', $value, $value, $value, $value -defined($type_constraint->(%s)) - || confess "Attribute (" . $attr->name . ") does not pass the type constraint (" - . $attr->type_constraint->name . ") with " . (defined(%s) ? "'%s'" : "undef") - if defined(%s); -EOF -} +sub _call_builder { + my ( $self, $instance ) = @_; -sub _inline_check_coercion { - my $self = shift; - return '' unless $self->should_coerce; - return 'my $val = $attr->type_constraint->coerce($_[1]);' -} + my $builder = $self->builder(); -sub _inline_check_required { - my $self = shift; - return '' unless $self->is_required; - return 'defined($_[1]) || confess "Attribute ($attr_name) is required, so cannot be set to undef";' -} + return $instance->$builder() + if $instance->can( $self->builder ); -sub _inline_check_lazy { - my $self = shift; - return '' unless $self->is_lazy; - if ($self->has_type_constraint) { - # NOTE: - # this could probably be cleaned - # up and streamlined a little more - return 'unless (exists $_[0]->{$attr_name}) {' . - ' if ($attr->has_default) {' . - ' my $default = $attr->default($_[0]);' . - ' (defined($type_constraint->($default)))' . - ' || confess "Attribute (" . $attr->name . ") does not pass the type constraint ("' . - ' . $attr->type_constraint->name . ") with " . (defined($default) ? "\'$default\'" : "undef")' . - ' if defined($default);' . - ' $_[0]->{$attr_name} = $default; ' . - ' }' . - ' else {' . - ' $_[0]->{$attr_name} = undef;' . - ' }' . - '}'; - } - return '$_[0]->{$attr_name} = ($attr->has_default ? $attr->default($_[0]) : undef)' - . 'unless exists $_[0]->{$attr_name};'; + $self->throw_error( blessed($instance) + . " does not support builder method '" + . $self->builder + . "' for attribute '" + . $self->name + . "'", + object => $instance, + ); } +## Slot management -sub _inline_store { - my ($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 $mi = $self->associated_class->get_meta_instance; - my $slot_name = sprintf "'%s'", $self->slots; + my $slot_name = $self->name; - my $code = $mi->inline_set_slot_value($instance, $slot_name, $value) . ";"; - $code .= $mi->inline_weaken_slot_value($instance, $slot_name, $value) . ";" - if $self->is_weak_ref; - return $code; -} + 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 $callback = sub { + my $val = $self->_coerce_and_verify( shift, $instance );; + + $meta_instance->set_slot_value($instance, $slot_name, $val); + }; + + my $initializer = $self->initializer; -sub _inline_trigger { - my ($self, $instance, $value) = @_; - return '' unless $self->has_trigger; - return sprintf('$attr->trigger->(%s, %s, $attr);', $instance, $value); + # most things will just want to set a value, so make it first arg + $instance->$initializer($value, $callback, $self); } -sub _inline_get { - my ($self, $instance) = @_; +sub set_value { + my ($self, $instance, @args) = @_; + my $value = $args[0]; - my $mi = $self->associated_class->get_meta_instance; - my $slot_name = sprintf "'%s'", $self->slots; + my $attr_name = $self->name; - return $mi->inline_get_slot_value($instance, $slot_name); + if ($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; + + $meta_instance->set_slot_value($instance, $attr_name, $value); + + if (ref $value && $self->is_weak_ref) { + $meta_instance->weaken_slot_value($instance, $attr_name); + } + + if ($self->has_trigger) { + $self->trigger->($instance, $value); + } } -sub _inline_auto_deref { - my ( $self, $ref_value ) = @_; +sub get_value { + my ($self, $instance) = @_; + + if ($self->is_lazy) { + unless ($self->has_value($instance)) { + my $value; + if ($self->has_default) { + $value = $self->default($instance); + } elsif ( $self->has_builder ) { + $value = $self->_call_builder($instance); + } - return $ref_value unless $self->should_auto_deref; + $value = $self->_coerce_and_verify( $value, $instance ); - my $type_constraint = $self->type_constraint; + $self->set_initial_value($instance, $value); + } + } + + if ($self->should_auto_deref) { + + my $type_constraint = $self->type_constraint; + + if ($type_constraint->is_a_type_of('ArrayRef')) { + my $rv = $self->SUPER::get_value($instance); + return unless defined $rv; + return wantarray ? @{ $rv } : $rv; + } + elsif ($type_constraint->is_a_type_of('HashRef')) { + my $rv = $self->SUPER::get_value($instance); + return unless defined $rv; + return wantarray ? %{ $rv } : $rv; + } + else { + $self->throw_error("Can not auto de-reference the type constraint '" . $type_constraint->name . "'", object => $instance, type_constraint => $type_constraint); + } - my $sigil; - if ($type_constraint->is_a_type_of('ArrayRef')) { - $sigil = '@'; - } - elsif ($type_constraint->is_a_type_of('HashRef')) { - $sigil = '%'; - } + } else { - confess "Can not auto de-reference the type constraint '" . $type_constraint->name . "'"; + + return $self->SUPER::get_value($instance); } +} + +## installing accessors - "(wantarray() ? $sigil\{ ( $ref_value ) || return } : ( $ref_value ) )"; +sub accessor_metaclass { 'Moose::Meta::Method::Accessor' } + +sub install_accessors { + my $self = shift; + $self->SUPER::install_accessors(@_); + $self->install_delegation if $self->has_handles; + return; } -sub generate_accessor_method { - my ($attr, $attr_name) = @_; - my $value_name = $attr->should_coerce ? '$val' : '$_[1]'; - my $mi = $attr->associated_class->get_meta_instance; - my $slot_name = sprintf "'%s'", $attr->slots; - my $inv = '$_[0]'; - my $code = 'sub { ' - . 'if (scalar(@_) == 2) {' - . $attr->_inline_check_required - . $attr->_inline_check_coercion - . $attr->_inline_check_constraint($value_name) - . $attr->_inline_store($inv, $value_name) - . $attr->_inline_trigger($inv, $value_name) - . ' }' - . $attr->_inline_check_lazy - . 'return ' . $attr->_inline_auto_deref($attr->_inline_get($inv)) - . ' }'; - - # NOTE: - # set up the environment - my $type_constraint = $attr->type_constraint - ? $attr->type_constraint->_compiled_type_constraint - : undef; - - my $sub = eval $code; - confess "Could not create accessor for '$attr_name' because $@ \n code: $code" if $@; - return $sub; +sub remove_accessors { + my $self = shift; + $self->SUPER::remove_accessors(@_); + $self->remove_delegation if $self->has_handles; + return; } -sub generate_writer_method { - my ($attr, $attr_name) = @_; - my $value_name = $attr->should_coerce ? '$val' : '$_[1]'; - my $inv = '$_[0]'; - my $code = 'sub { ' - . $attr->_inline_check_required - . $attr->_inline_check_coercion - . $attr->_inline_check_constraint($value_name) - . $attr->_inline_store($inv, $value_name) - . $attr->_inline_trigger($inv, $value_name) - . ' }'; - +sub install_delegation { + my $self = shift; + # NOTE: - # set up the environment - my $type_constraint = $attr->type_constraint - ? $attr->type_constraint->_compiled_type_constraint - : undef; - - my $sub = eval $code; - confess "Could not create writer for '$attr_name' because $@ \n code: $code" if $@; - return $sub; -} + # 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)) + || $self->throw_error("You cannot overwrite a locally defined method ($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. + + # 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); -sub generate_reader_method { - my $attr = shift; - my $attr_name = $attr->slots; - my $code = 'sub {' - . 'confess "Cannot assign a value to a read-only accessor" if @_ > 1;' - . $attr->_inline_check_lazy - . 'return ' . $attr->_inline_auto_deref( '$_[0]->{$attr_name}' ) . ';' - . '}'; - my $sub = eval $code; - confess "Could not create reader for '$attr_name' because $@ \n code: $code" if $@; - return $sub; + $self->associated_class->add_method($method->name, $method); + } } -sub install_accessors { +sub remove_delegation { my $self = shift; - $self->SUPER::install_accessors(@_); - - if ($self->has_handles) { - - # 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}; - - (!$associated_class->has_method($handle)) - || confess "You cannot overwrite a locally defined method ($handle) with a delegation"; - - if ((reftype($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 - ((shift)->$accessor_name())->$method_to_call(@_); - }); - } - } + my %handles = $self->_canonicalize_handles; + my $associated_class = $self->associated_class; + foreach my $handle (keys %handles) { + $self->associated_class->remove_method($handle); } - - return; } # private methods to help delegation ... @@ -445,45 +599,53 @@ sub install_accessors { sub _canonicalize_handles { my $self = shift; my $handles = $self->handles; - if (ref($handles) eq 'HASH') { - return %{$handles}; - } - elsif (ref($handles) eq 'ARRAY') { - return map { $_ => $_ } @{$handles}; - } - elsif (ref($handles) eq 'Regexp') { - ($self->has_type_constraint) - || confess "Cannot delegate methods based on a RegExpr without a type constraint (isa)"; - return map { ($_ => $_) } - grep { $handles } $self->_get_delegate_method_list; - } - elsif (ref($handles) eq 'CODE') { - return $handles->($self, $self->_find_delegate_metaclass); + if (my $handle_type = ref($handles)) { + if ($handle_type eq 'HASH') { + return %{$handles}; + } + elsif ($handle_type eq 'ARRAY') { + return map { $_ => $_ } @{$handles}; + } + elsif ($handle_type eq 'Regexp') { + ($self->has_type_constraint) + || $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); + } + else { + $self->throw_error("Unable to canonicalize the 'handles' option with $handles", data => $handles); + } } else { - confess "Unable to canonicalize the 'handles' option with $handles"; + Class::MOP::load_class($handles); + my $role_meta = Class::MOP::class_of($handles); + + (blessed $role_meta && $role_meta->isa('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 + ); } } 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); } } @@ -491,18 +653,71 @@ 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; + 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__ @@ -515,111 +730,342 @@ 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. + +=head1 INHERITANCE -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. +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. + +=head2 Creation + +=over 4 + +=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' or 'rw' + +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. + +=item * isa => $type + +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. + +This option can also accept a L object. + +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. -These methods override methods in L and add -Moose specific features. You can safely assume though that they -will behave just as L does. +=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, 'forty-two') }; + if($@) { + print "Oops: $@\n"; + } + +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. + +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, +fetch the type_constraint from the attribute using L +and call L. See L +for an example. + +=back + +=head2 Attribute Accessor generation =over 4 -=item B +=item B<< $attr->install_accessors >> -=item B +This method overrides the parent to also install delegation methods. -=item B +=item B<< $attr->remove_accessors >> -=item B +This method overrides the parent to also remove delegation methods. -=item B +=item B<< $attr->install_delegation >> -=item B +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 exists to allow a custom metaclass to change or add to the list +of options which can be changed. + +=item B<< $attr->type_constraint >> + +Returns the L object for this attribute, +if it has one. + +=item B<< $attr->has_type_constraint >> + +Returns true if this attribute has a type constraint. + +=item B<< $attr->verify_against_type_constraint($value) >> + +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<< $attr->handles >> + +This returns the value of the C option passed to the +constructor. + +=item B<< $attr->has_handles >> -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. +Returns true if this attribute performs delegation. -=item B +=item B<< $attr->is_weak_ref >> -Returns true if this meta-attribute has a type constraint. +Returns true if this attribute stores its value as a weak reference. -=item B +=item B<< $attr->is_required >> -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 is required to have a value. -=item B +=item B<< $attr->is_lazy >> -Returns true if this meta-attribute performs delegation. +Returns true if this attribute is lazy. -=item B +=item B<< $attr->is_lazy_build >> -This returns the value which was passed into the handles option. +Returns true if the C option was true when passed to the +constructor. -=item B +=item B<< $attr->should_coerce >> -Returns true if this meta-attribute produces a weak reference. +Returns true if the C option passed to the constructor was +true. -=item B +=item B<< $attr->should_auto_deref >> -Returns true if this meta-attribute is required to have a value. +Returns true if the C option passed to the constructor was +true. -=item B +=item B<< $attr->trigger >> -Returns true if this meta-attribute should be initialized lazily. +This is the subroutine reference that was in the C option +passed to the constructor, if any. -NOTE: lazy attributes, B have a C field set. +=item B<< $attr->has_trigger >> -=item B +Returns true if this attribute has a trigger set. -Returns true if this meta-attribute should perform type coercion. +=item B<< $attr->documentation >> -=item B +Returns the value 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_documentation >> -NOTE: This can only be done for attributes whose type constraint is -either I or I. +Returns true if this attribute has any documentation. -=item B +=item B<< $attr->applied_traits >> -Returns true if this meta-attribute has a trigger set. +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 >> -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 traits applied. =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. @@ -631,11 +1077,11 @@ Yuval Kogman Enothingmuch@woobling.comE =head1 COPYRIGHT AND LICENSE -Copyright 2006 by Infinity Interactive, Inc. +Copyright 2006-2009 by Infinity Interactive, Inc. L 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