X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMoose%2FMeta%2FAttribute.pm;h=217c1ec0eec14b5c52916d2803bf24e88e0cf827;hb=d03bd989b97597428b460d7f9a021e2931893fa0;hp=7111abce915def9b4c8085be7beda9f71674c923;hpb=525129a5a7413b8c2ea745d170a1913e93bfd4bf;p=gitmo%2FMoose.git diff --git a/lib/Moose/Meta/Attribute.pm b/lib/Moose/Meta/Attribute.pm index 7111abc..217c1ec 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 = '0.69'; +our $VERSION = '0.75_01'; our $AUTHORITY = 'cpan:STEVAN'; use Moose::Meta::Method::Accessor; @@ -51,8 +51,8 @@ __PACKAGE__->meta->add_attribute('traits' => ( predicate => 'has_applied_traits', )); -# we need to have a ->does method in here to -# more easily support traits, and the introspection +# we need to have a ->does method in here to +# more easily support traits, and the introspection # of those traits. We extend the does check to look # for metatrait aliases. sub does { @@ -84,7 +84,7 @@ sub interpolate_class_and_new { my ($class, $name, @args) = @_; my ( $new_class, @traits ) = $class->interpolate_class(@args); - + $new_class->new($name, @args, ( scalar(@traits) ? ( traits => \@traits ) : () ) ); } @@ -95,7 +95,7 @@ sub interpolate_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 $new_class->interpolate_class(%options); @@ -142,52 +142,53 @@ sub interpolate_class { # ... my @legal_options_for_inheritance = qw( - default coerce required - documentation lazy handles + default coerce required + documentation lazy handles builder type_constraint definition_context + lazy_build ); sub legal_options_for_inheritance { @legal_options_for_inheritance } # NOTE/TODO -# This method *must* be able to handle -# Class::MOP::Attribute instances as -# well. Yes, I know that is wrong, but -# apparently we didn't realize it was -# doing that and now we have some code -# which is dependent on it. The real -# solution of course is to push this +# This method *must* be able to handle +# Class::MOP::Attribute instances as +# well. Yes, I know that is wrong, but +# apparently we didn't realize it was +# doing that and now we have some code +# which is dependent on it. The real +# solution of course is to push this # feature back up into Class::MOP::Attribute # but I not right now, I am too lazy. -# However if you are reading this and -# looking for something to do,.. please +# However if you are reading this and +# looking for something to do,.. please # be my guest. # - stevan sub clone_and_inherit_options { my ($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; @@ -203,7 +204,7 @@ 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')) { @@ -217,10 +218,10 @@ 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')) { @@ -245,28 +246,23 @@ sub clone { my $class = $params{metaclass} || ref $self; - if ( 0 and $class eq ref $self ) { - return $self->SUPER::clone(%params); - } else { - my ( @init, @non_init ); - - foreach my $attr ( grep { $_->has_value($self) } $self->meta->compute_all_applicable_attributes ) { - push @{ $attr->has_init_arg ? \@init : \@non_init }, $attr; - } - - my %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params ); + my ( @init, @non_init ); - my $name = delete $new_params{name}; + 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 $clone = $class->new($name, %new_params, __hack_no_process_options => 1 ); + my %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params ); - foreach my $attr ( @non_init ) { - $attr->set_value($clone, $attr->get_value($self)); - } + my $name = delete $new_params{name}; + 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 $clone; } sub _process_options { @@ -280,7 +276,7 @@ sub _process_options { ## is => rw, accessor => _foo # turns into (accessor => _foo) ## is => ro, accessor => _foo # error, accesor is rw ### ------------------------- - + if ($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 $options->{accessor}; @@ -357,7 +353,7 @@ sub _process_options { if ($name =~ /^_/) { $options->{clearer} ||= "_clear${name}"; $options->{predicate} ||= "_has${name}"; - } + } else { $options->{clearer} ||= "clear_${name}"; $options->{predicate} ||= "has_${name}"; @@ -384,7 +380,7 @@ 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; + $value_is_set = 1; } else { # skip it if it's lazy @@ -398,7 +394,7 @@ sub initialize_instance_slot { if ($self->has_default) { $val = $self->default($instance); $value_is_set = 1; - } + } elsif ($self->has_builder) { $val = $self->_call_builder($instance); $value_is_set = 1; @@ -407,13 +403,7 @@ 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); - } - $self->verify_against_type_constraint($val, instance => $instance); - } + $val = $self->_coerce_and_verify( $val, $instance ); $self->set_initial_value($instance, $val); $meta_instance->weaken_slot_value($instance, $self->name) @@ -441,8 +431,8 @@ 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 { @@ -460,15 +450,11 @@ sub _set_initial_slot_value { } my $callback = sub { - my $val = shift; - if ($type_constraint) { - $val = $type_constraint->coerce($val) - if $can_coerce; - $self->verify_against_type_constraint($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 @@ -485,19 +471,7 @@ 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; @@ -524,12 +498,9 @@ 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); - $self->verify_against_type_constraint($value); - } + + $value = $self->_coerce_and_verify( $value, $instance ); + $self->set_initial_value($instance, $value); } } @@ -611,7 +582,7 @@ sub install_delegation { my $method = $self->_make_delegation_method($handle, $method_to_call); $self->associated_class->add_method($method->name, $method); - } + } } sub remove_delegation { @@ -649,17 +620,11 @@ sub _canonicalize_handles { } } else { - Class::MOP::load_class($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 => $@); - } + my $role_meta = Class::MOP::load_class($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 @@ -670,19 +635,13 @@ 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); @@ -723,6 +682,23 @@ sub _make_delegation_method { ); } +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; @@ -753,43 +729,153 @@ 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. -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' 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. -=item B +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 B +=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 B +=item * does => $role -=item B +This is short-hand for saying that the attribute's type must be an +object which does the named role. -=item B +=item * coerce => $bool -=item B +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 @@ -816,141 +902,163 @@ 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. + +=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 - -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. - -=item B +Effectively, this method is a factory that finds or creates the +appropriate class for the given C and/or C. -Whitelist with options you can change. You can overload it in your custom -metaclass to allow your options be inheritable. +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) >> -Returns true if this meta-attribute has a type constraint. +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. -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. +=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. -Verifies that the given value is valid under this attribute's type -constraint, otherwise throws an error. +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