X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMoose%2FMeta%2FAttribute.pm;h=f7a0e3460565bd43ed1d228eb5416be8bb9428a1;hb=6f94c802188d44415bafdd64422cecd24585a289;hp=0409a90a36d6fc2bf9ec2914ccd14ee486990566;hpb=82750a8aa67b0f6cd139537bef64162d7a7c4d52;p=gitmo%2FMoose.git diff --git a/lib/Moose/Meta/Attribute.pm b/lib/Moose/Meta/Attribute.pm index 0409a90..f7a0e34 100644 --- a/lib/Moose/Meta/Attribute.pm +++ b/lib/Moose/Meta/Attribute.pm @@ -7,7 +7,7 @@ use warnings; use Scalar::Util 'blessed', 'weaken'; use overload (); -our $VERSION = '0.62_01'; +our $VERSION = '0.87'; our $AUTHORITY = 'cpan:STEVAN'; use Moose::Meta::Method::Accessor; @@ -40,6 +40,7 @@ __PACKAGE__->meta->add_attribute('trigger' => ( )); __PACKAGE__->meta->add_attribute('handles' => ( reader => 'handles', + writer => '_set_handles', predicate => 'has_handles', )); __PACKAGE__->meta->add_attribute('documentation' => ( @@ -51,8 +52,8 @@ __PACKAGE__->meta->add_attribute('traits' => ( predicate => 'has_applied_traits', )); -# we need to have a ->does method in here to -# more easily support traits, and the introspection +# we need to have a ->does method in here to +# more easily support traits, and the introspection # of those traits. We extend the does check to look # for metatrait aliases. sub does { @@ -77,28 +78,45 @@ sub throw_error { sub new { my ($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, $name, @args) = @_; + my ($class, $name, %args) = @_; - my ( $new_class, @traits ) = $class->interpolate_class(@args); - - $new_class->new($name, @args, ( scalar(@traits) ? ( traits => \@traits ) : () ) ); + my ( $new_class, @traits ) = $class->interpolate_class(\%args); + + $new_class->new($name, %args, ( scalar(@traits) ? ( traits => \@traits ) : () ) ); } sub interpolate_class { - my ($class, %options) = @_; + my ($class, $options) = @_; $class = ref($class) || $class; - if ( my $metaclass_name = delete $options{metaclass} ) { + 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); + return $new_class->interpolate_class($options); } else { $class = $new_class; } @@ -107,12 +125,25 @@ sub interpolate_class { my @traits; - if (my $traits = $options{traits}) { - if ( @traits = grep { not $class->does($_) } map { - Moose::Util::resolve_metatrait_alias( Attribute => $_ ) - or - $_ - } @$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 => [ $class ], roles => [ @traits ], @@ -129,51 +160,53 @@ sub interpolate_class { # ... my @legal_options_for_inheritance = qw( - default coerce required - documentation lazy handles + default coerce required + documentation lazy handles builder type_constraint + definition_context + lazy_build ); sub legal_options_for_inheritance { @legal_options_for_inheritance } # NOTE/TODO -# This method *must* be able to handle -# Class::MOP::Attribute instances as -# well. Yes, I know that is wrong, but -# apparently we didn't realize it was -# doing that and now we have some code -# which is dependent on it. The real -# solution of course is to push this +# This method *must* be able to handle +# Class::MOP::Attribute instances as +# well. Yes, I know that is wrong, but +# apparently we didn't realize it was +# doing that and now we have some code +# which is dependent on it. The real +# solution of course is to push this # feature back up into Class::MOP::Attribute # but I not right now, I am too lazy. -# However if you are reading this and -# looking for something to do,.. please +# However if you are reading this and +# looking for something to do,.. please # be my guest. # - stevan sub clone_and_inherit_options { my ($self, %options) = @_; - + my %copy = %options; - + my %actual_options; - + # 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 + # 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}; } - } + } if ($options{isa}) { my $type_constraint; @@ -189,7 +222,7 @@ sub clone_and_inherit_options { $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')) { @@ -203,14 +236,14 @@ sub clone_and_inherit_options { $actual_options{type_constraint} = $type_constraint; delete $options{does}; - } + } # NOTE: - # this doesn't apply to Class::MOP::Attributes, + # this doesn't apply to Class::MOP::Attributes, # so we can ignore it for them. # - SL if ($self->can('interpolate_class')) { - ( $actual_options{metaclass}, my @traits ) = $self->interpolate_class(%options); + ( $actual_options{metaclass}, my @traits ) = $self->interpolate_class(\%options); my %seen; my @all_traits = grep { $seen{$_}++ } @{ $self->applied_traits || [] }, @traits; @@ -229,30 +262,25 @@ sub clone_and_inherit_options { sub clone { my ( $self, %params ) = @_; - my $class = $params{metaclass} || ref $self; - - if ( 0 and $class eq ref $self ) { - return $self->SUPER::clone(%params); - } else { - my ( @init, @non_init ); + my $class = delete $params{metaclass} || ref $self; - foreach my $attr ( grep { $_->has_value($self) } $self->meta->compute_all_applicable_attributes ) { - push @{ $attr->has_init_arg ? \@init : \@non_init }, $attr; - } + my ( @init, @non_init ); - my %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params ); + 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 $name = delete $new_params{name}; + my %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params ); - my $clone = $class->new($name, %new_params, __hack_no_process_options => 1 ); + my $name = delete $new_params{name}; - foreach my $attr ( @non_init ) { - $attr->set_value($clone, $attr->get_value($self)); - } + my $clone = $class->new($name, %new_params, __hack_no_process_options => 1 ); - - return $clone; + foreach my $attr ( @non_init ) { + $attr->set_value($clone, $attr->get_value($self)); } + + return $clone; } sub _process_options { @@ -266,7 +294,7 @@ sub _process_options { ## is => rw, accessor => _foo # turns into (accessor => _foo) ## is => ro, accessor => _foo # error, accesor is rw ### ------------------------- - + if ($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}; @@ -280,6 +308,9 @@ sub _process_options { $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}); } @@ -338,12 +369,11 @@ sub _process_options { $class->throw_error("You can not use lazy_build and default for the same attribute ($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}"; @@ -370,7 +400,7 @@ sub initialize_instance_slot { my $value_is_set; if ( defined($init_arg) and exists $params->{$init_arg}) { $val = $params->{$init_arg}; - $value_is_set = 1; + $value_is_set = 1; } else { # skip it if it's lazy @@ -384,7 +414,7 @@ sub initialize_instance_slot { if ($self->has_default) { $val = $self->default($instance); $value_is_set = 1; - } + } elsif ($self->has_builder) { $val = $self->_call_builder($instance); $value_is_set = 1; @@ -393,17 +423,7 @@ sub initialize_instance_slot { 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); - } - $type_constraint->check($val) - || $self->throw_error("Attribute (" - . $self->name - . ") does not pass the type constraint because: " - . $type_constraint->get_message($val), data => $val, object => $instance); - } + $val = $self->_coerce_and_verify( $val, $instance ); $self->set_initial_value($instance, $val); $meta_instance->weaken_slot_value($instance, $self->name) @@ -431,8 +451,8 @@ sub _call_builder { ## Slot management # FIXME: -# this duplicates too much code from -# Class::MOP::Attribute, we need to +# this duplicates too much code from +# Class::MOP::Attribute, we need to # refactor these bits eventually. # - SL sub _set_initial_slot_value { @@ -450,19 +470,11 @@ sub _set_initial_slot_value { } my $callback = sub { - my $val = shift; - if ($type_constraint) { - $val = $type_constraint->coerce($val) - if $can_coerce; - $type_constraint->check($val) - || $self->throw_error("Attribute (" - . $slot_name - . ") does not pass the type constraint because: " - . $type_constraint->get_message($val), data => $val, object => $instance); - } + my $val = $self->_coerce_and_verify( shift, $instance );; + $meta_instance->set_slot_value($instance, $slot_name, $val); }; - + my $initializer = $self->initializer; # most things will just want to set a value, so make it first arg @@ -479,19 +491,7 @@ sub set_value { $self->throw_error("Attribute ($attr_name) is required", object => $instance); } - if ($self->has_type_constraint) { - - my $type_constraint = $self->type_constraint; - - if ($self->should_coerce) { - $value = $type_constraint->coerce($value); - } - $type_constraint->_compiled_type_constraint->($value) - || $self->throw_error("Attribute (" - . $self->name - . ") does not pass the type constraint because " - . $type_constraint->get_message($value), object => $instance, data => $value); - } + $value = $self->_coerce_and_verify( $value, $instance ); my $meta_instance = Class::MOP::Class->initialize(blessed($instance)) ->get_meta_instance; @@ -503,7 +503,7 @@ sub set_value { } if ($self->has_trigger) { - $self->trigger->($instance, $value, $self); + $self->trigger->($instance, $value); } } @@ -518,15 +518,9 @@ sub get_value { } elsif ( $self->has_builder ) { $value = $self->_call_builder($instance); } - if ($self->has_type_constraint) { - my $type_constraint = $self->type_constraint; - $value = $type_constraint->coerce($value) - if ($self->should_coerce); - $type_constraint->check($value) - || $self->throw_error("Attribute (" . $self->name - . ") does not pass the type constraint because: " - . $type_constraint->get_message($value), type_constraint => $type_constraint, data => $value); - } + + $value = $self->_coerce_and_verify( $value, $instance ); + $self->set_initial_value($instance, $value); } } @@ -567,6 +561,38 @@ sub install_accessors { return; } +sub _check_associated_methods { + my $self = shift; + unless ( + @{ $self->associated_methods } + || ($self->_is_metadata || '') eq 'bare' + ) { + Carp::cluck( + 'Attribute (' . $self->name . ') of class ' + . $self->associated_class->name + . ' has no associated methods' + . ' (did you mean to provide an "is" argument?)' + . "\n" + ) + } +} + +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 $self->definition_context->{package})) { + Carp::cluck( + "You are overwriting a locally defined method ($accessor) with " + . "an accessor" + ); + } + $self->SUPER::_process_accessors(@_); +} + sub remove_accessors { my $self = shift; $self->SUPER::remove_accessors(@_); @@ -608,7 +634,8 @@ sub install_delegation { my $method = $self->_make_delegation_method($handle, $method_to_call); $self->associated_class->add_method($method->name, $method); - } + $self->associate_method($method); + } } sub remove_delegation { @@ -634,32 +661,30 @@ sub _canonicalize_handles { } elsif ($handle_type eq 'Regexp') { ($self->has_type_constraint) - || $self->throw_error("Cannot delegate methods based on a RegExpr without a type constraint (isa)", data => $handles); + || $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 { $self->throw_error("Unable to canonicalize the 'handles' option with $handles", data => $handles); } } else { - Class::MOP::load_class($handles) - unless Class::MOP::is_class_loaded($handles); - - my $role_meta = eval { $handles->meta }; - if ($@) { - $self->throw_error("Unable to canonicalize the 'handles' option with $handles because : $@", data => $handles, error => $@); - } + Class::MOP::load_class($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 ->meta is not a Moose::Meta::Role", data => $handles); - + || $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, ); } } @@ -667,19 +692,13 @@ 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 { $self->throw_error("Cannot find delegate metaclass for attribute " . $self->name); @@ -702,6 +721,8 @@ sub _get_delegate_method_list { } } +sub delegation_metaclass { 'Moose::Meta::Method::Delegation' } + sub _make_delegation_method { my ( $self, $handle_name, $method_to_call ) = @_; @@ -710,14 +731,52 @@ sub _make_delegation_method { $method_body = $method_to_call if 'CODE' eq ref($method_to_call); - return Moose::Meta::Method::Delegation->new( + my $curried_arguments = []; + + ($method_to_call, $curried_arguments) = @$method_to_call + if 'ARRAY' 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, + curried_arguments => $curried_arguments || [], ); } +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' } @@ -733,52 +792,169 @@ 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 + +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. + +=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 -=item B +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 B +=item * weak_ref => $bool -=item B +If this is true, the attribute's value will be stored as a weak +reference. -=item B +=item * auto_deref => $bool -=item B +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 B +=item * lazy_build => $bool -=item B +Setting this to true makes the attribute lazy and provides a number of +default methods. -=item B + has 'size' => ( + is => 'ro', + lazy_build => 1, + ); + +is equivalent to this: + + has 'size' => ( + is => 'ro', + lazy => 1, + builder => '_build_size', + clearer => 'clear_size', + predicate => 'has_size', + ); + +=item * documentation + +An arbitrary string that can be retrieved later by calling C<< +$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 @@ -794,136 +970,168 @@ 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) >> -Delegates to C or C if there is none. +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. -=item B +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 +=item B<< Moose::Meta::Class->interpolate_class_and_new($name, %options) >> -When called as a class method causes interpretation of the C and +This is an alternate constructor that handles the C and C options. -=item B +Effectively, this method is a factory that finds or creates the +appropriate class for the given C and/or C. -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. +Once it has the appropriate class, it will call C<< $class->new($name, +%options) >> on that class. -=item B +=item B<< $attr->clone_and_inherit_options(%options) >> -Whitelist with options you can change. You can overload it in your custom -metaclass to allow your options be inheritable. +This method supports the C feature. It does various bits +of processing on the supplied C<%options> before ultimately calling +the C method. -=item B +One of its main tasks is to make sure that the C<%options> provided +only includes the options returned by the +C method. -Returns true if this meta-attribute has a type constraint. +=item B<< $attr->legal_options_for_inheritance >> -=item B +This returns a whitelist of options that can be overridden in a +subclass's attribute definition. -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. +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 performs delegation. +Returns the L object for this attribute, +if it has one. -=item B +=item B<< $attr->has_type_constraint >> -This returns the value which was passed into the handles option. +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 produces a weak reference. +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 >> -Returns true if this meta-attribute is required to have a value. +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 should be initialized lazily. +Returns true if this attribute performs delegation. -NOTE: lazy attributes, B have a C or C field set. +=item B<< $attr->is_weak_ref >> -=item B +Returns true if this attribute stores its value as a weak reference. -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_required >> - #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 this attribute is required to have a value. - #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->is_lazy >> -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 this attribute is lazy. -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->is_lazy_build >> -=item B +Returns true if the C option was true when passed to the +constructor. -Returns true if this meta-attribute should perform type coercion. +=item B<< $attr->should_coerce >> -=item B +Returns true if the C option passed to the constructor was +true. -Returns true if this meta-attribute should perform automatic -auto-dereferencing. +=item B<< $attr->should_auto_deref >> -NOTE: This can only be done for attributes whose type constraint is -either I or I. +Returns true if the C option passed to the constructor was +true. -=item B +=item B<< $attr->trigger >> -Returns true if this meta-attribute has a trigger set. +This is the subroutine reference that was in the C option +passed to the constructor, if any. -=item B +=item B<< $attr->has_trigger >> -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 a trigger set. -=item B +=item B<< $attr->documentation >> -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. +Returns the value that was in the C option passed to +the constructor, if any. -=item B +=item B<< $attr->has_documentation >> -Returns true if this meta-attribute has any documentation. +Returns true if this attribute has any documentation. -=item B +=item B<< $attr->applied_traits >> -This will return the ARRAY ref of all the traits applied to this -attribute, or if no traits have been applied, it returns C. +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 traits applied. +Returns true if this attribute has any traits applied. =back @@ -941,7 +1149,7 @@ Yuval Kogman Enothingmuch@woobling.comE =head1 COPYRIGHT AND LICENSE -Copyright 2006-2008 by Infinity Interactive, Inc. +Copyright 2006-2009 by Infinity Interactive, Inc. L