X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=gitmo%2FMouse.git;a=blobdiff_plain;f=lib%2FMouse%2FMeta%2FAttribute.pm;h=315eaa4591e046bab9727242944d12b881ffd472;hp=4feac11dd03d1b2e5118ce42ee7d5d153bf715f2;hb=637d4f17e6965551c032a3115dcbbb4d8e01fbf5;hpb=4a29b63e8d38182682b0c13ac0260f708cb1b89f diff --git a/lib/Mouse/Meta/Attribute.pm b/lib/Mouse/Meta/Attribute.pm index 4feac11..315eaa4 100644 --- a/lib/Mouse/Meta/Attribute.pm +++ b/lib/Mouse/Meta/Attribute.pm @@ -1,211 +1,105 @@ package Mouse::Meta::Attribute; -use strict; -use warnings; +use Mouse::Util qw(:meta); # enables strict and warnings use Carp (); -use Mouse::Util qw(:meta); - use Mouse::Meta::TypeConstraint; -use Mouse::Meta::Method::Accessor; - -sub _process_options{ - my($class, $name, $args) = @_; - - # taken from Class::MOP::Attribute::new - - defined($name) - or $class->throw_error('You must provide a name for the attribute'); - - if(!exists $args->{init_arg}){ - $args->{init_arg} = $name; - } - - # 'required' requires eigher 'init_arg', 'builder', or 'default' - my $can_be_required = defined( $args->{init_arg} ); - - if(exists $args->{builder}){ - $class->throw_error('builder must be a defined scalar value which is a method name') - if ref $args->{builder} || !(defined $args->{builder}); - - $can_be_required++; - } - elsif(exists $args->{default}){ - if(ref $args->{default} && ref($args->{default}) ne 'CODE'){ - $class->throw_error("References are not allowed as default values, you must " - . "wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])"); - } - $can_be_required++; - } - - if( $args->{required} && !$can_be_required ) { - $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg"); - } - # taken from Mouse::Meta::Attribute->new and _process_args-> - - if(exists $args->{is}){ - my $is = $args->{is}; - - if($is eq 'ro'){ - $args->{reader} ||= $name; - } - elsif($is eq 'rw'){ - if(exists $args->{writer}){ - $args->{reader} ||= $name; - } - else{ - $args->{accessor} ||= $name; - } - } - elsif($is eq 'bare'){ - # do nothing, but don't complain (later) about missing methods - } - else{ - $is = 'undef' if !defined $is; - $class->throw_error("I do not understand this option (is => $is) on attribute ($name)"); - } - } - - my $tc; - if(exists $args->{isa}){ - $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($args->{isa}); - } - elsif(exists $args->{does}){ - # TODO - # $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_does_type_constraint($args->{does}); - } - $tc = $args->{type_constraint}; - - if($args->{coerce}){ - defined($tc) - || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)"); - - $args->{weak_ref} - && $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)"); - } - - if ($args->{lazy_build}) { - exists($args->{default}) - && $class->throw_error("You can not use lazy_build and default for the same attribute ($name)"); - - $args->{lazy} = 1; - $args->{builder} ||= "_build_${name}"; - if ($name =~ /^_/) { - $args->{clearer} ||= "_clear${name}"; - $args->{predicate} ||= "_has${name}"; - } - else { - $args->{clearer} ||= "clear_${name}"; - $args->{predicate} ||= "has_${name}"; - } - } - - if ($args->{auto_deref}) { - defined($tc) - || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)"); - - ( $tc->is_a_type_of('ArrayRef') || $tc->is_a_type_of('HashRef') ) - || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"); - } +my %valid_options = map { $_ => undef } ( + 'accessor', + 'auto_deref', + 'builder', + 'clearer', + 'coerce', + 'default', + 'documentation', + 'does', + 'handles', + 'init_arg', + 'is', + 'isa', + 'lazy', + 'lazy_build', + 'name', + 'predicate', + 'reader', + 'required', + 'traits', + 'trigger', + 'type_constraint', + 'weak_ref', + 'writer', + + # internally used + 'associated_class', + 'associated_methods', + + # Moose defines, but Mouse doesn't + #'definition_context', + #'initializer', + #'insertion_order', + + # special case for AttributeHelpers + 'provides', + 'curries', +); - if (exists $args->{trigger}) { - ('CODE' eq ref $args->{trigger}) - || $class->throw_error("Trigger must be a CODE ref on attribute ($name)"); - } +sub new { + my $class = shift; + my $name = shift; - if ($args->{lazy}) { - (exists $args->{default} || defined $args->{builder}) - || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it"); - } + my $args = $class->Mouse::Object::BUILDARGS(@_); # XXX: for backward compatibility (with method modifiers) if($class->can('canonicalize_args') != \&canonicalize_args){ %{$args} = $class->canonicalize_args($name, %{$args}); } - return; -} -sub new { - my $class = shift; - my $name = shift; + $class->_process_options($name, $args); - my %args = (@_ == 1) ? %{ $_[0] } : @_; + $args->{name} = $name; - $class->_process_options($name, \%args); + # check options + # (1) known by core + my @bad = grep{ !exists $valid_options{$_} } keys %{$args}; - $args{name} = $name; + # (2) known by subclasses + if(@bad && $class ne __PACKAGE__){ + my %valid_attrs = ( + map { $_ => undef } + grep { defined } + map { $_->init_arg() } + $class->meta->get_all_attributes() + ); + @bad = grep{ !exists $valid_attrs{$_} } @bad; + } - my $instance = bless \%args, $class; + # (3) bad options found + if(@bad){ + @bad = sort @bad; + Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad"); + } + + my $self = bless $args, $class; # extra attributes if($class ne __PACKAGE__){ - $class->meta->_initialize_instance($instance,\%args); + $class->meta->_initialize_object($self, $args); } -# XXX: there is no fast way to check attribute validity -# my @bad = ...; -# if(@bad){ -# @bad = sort @bad; -# Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad"); -# } - - return $instance + return $self; } -# readers - -sub name { $_[0]->{name} } -sub associated_class { $_[0]->{associated_class} } - -sub accessor { $_[0]->{accessor} } -sub reader { $_[0]->{reader} } -sub writer { $_[0]->{writer} } -sub predicate { $_[0]->{predicate} } -sub clearer { $_[0]->{clearer} } -sub handles { $_[0]->{handles} } - -sub _is_metadata { $_[0]->{is} } -sub is_required { $_[0]->{required} } -sub default { $_[0]->{default} } -sub is_lazy { $_[0]->{lazy} } -sub is_lazy_build { $_[0]->{lazy_build} } -sub is_weak_ref { $_[0]->{weak_ref} } -sub init_arg { $_[0]->{init_arg} } -sub type_constraint { $_[0]->{type_constraint} } - -sub trigger { $_[0]->{trigger} } -sub builder { $_[0]->{builder} } -sub should_auto_deref { $_[0]->{auto_deref} } -sub should_coerce { $_[0]->{coerce} } - -sub get_read_method { $_[0]->{reader} || $_[0]->{accessor} } -sub get_write_method { $_[0]->{writer} || $_[0]->{accessor} } - -# predicates - -sub has_accessor { exists $_[0]->{accessor} } -sub has_reader { exists $_[0]->{reader} } -sub has_writer { exists $_[0]->{writer} } -sub has_predicate { exists $_[0]->{predicate} } -sub has_clearer { exists $_[0]->{clearer} } -sub has_handles { exists $_[0]->{handles} } - -sub has_default { exists $_[0]->{default} } -sub has_type_constraint { exists $_[0]->{type_constraint} } -sub has_trigger { exists $_[0]->{trigger} } -sub has_builder { exists $_[0]->{builder} } - -sub has_read_method { exists $_[0]->{reader} || exists $_[0]->{accessor} } -sub has_write_method { exists $_[0]->{writer} || exists $_[0]->{accessor} } - -sub _create_args { +sub has_read_method { $_[0]->has_reader || $_[0]->has_accessor } +sub has_write_method { $_[0]->has_writer || $_[0]->has_accessor } + +sub _create_args { # DEPRECATED $_[0]->{_create_args} = $_[1] if @_ > 1; $_[0]->{_create_args} } sub interpolate_class{ - my($class, $name, $args) = @_; + my($class, $args) = @_; if(my $metaclass = delete $args->{metaclass}){ $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass ); @@ -238,7 +132,7 @@ sub interpolate_class{ return( $class, @traits ); } -sub canonicalize_args{ +sub canonicalize_args{ # DEPRECATED my ($self, $name, %args) = @_; Carp::cluck("$self->canonicalize_args has been deprecated." @@ -247,7 +141,7 @@ sub canonicalize_args{ return %args; } -sub create { +sub create { # DEPRECATED my ($self, $class, $name, %args) = @_; Carp::cluck("$self->create has been deprecated." @@ -257,51 +151,66 @@ sub create { return $self; } -sub verify_against_type_constraint { - my ($self, $value) = @_; - my $tc = $self->type_constraint; - return 1 unless $tc; +sub _coerce_and_verify { + my($self, $value, $instance) = @_; - local $_ = $value; - return 1 if $tc->check($value); + my $type_constraint = $self->{type_constraint}; + return $value if !defined $type_constraint; - $self->verify_type_constraint_error($self->name, $value, $tc); -} + if ($self->should_coerce && $type_constraint->has_coercion) { + $value = $type_constraint->coerce($value); + } + + $self->verify_against_type_constraint($value); -sub verify_type_constraint_error { - my($self, $name, $value, $type) = @_; - $self->throw_error("Attribute ($name) does not pass the type constraint because: " . $type->get_message($value)); + return $value; } -sub coerce_constraint { ## my($self, $value) = @_; - my $type = $_[0]->{type_constraint} - or return $_[1]; - return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $type, $_[1]); +sub verify_against_type_constraint { + my ($self, $value) = @_; + + my $type_constraint = $self->{type_constraint}; + return 1 if !$type_constraint; + return 1 if $type_constraint->check($value); + + $self->_throw_type_constraint_error($value, $type_constraint); } -sub _canonicalize_handles { - my $self = shift; - my $handles = shift; +sub _throw_type_constraint_error { + my($self, $value, $type) = @_; - if (ref($handles) eq 'HASH') { - return %$handles; - } - elsif (ref($handles) eq 'ARRAY') { - return map { $_ => $_ } @$handles; - } - else { - $self->throw_error("Unable to canonicalize the 'handles' option with $handles"); - } + $self->throw_error( + sprintf q{Attribute (%s) does not pass the type constraint because: %s}, + $self->name, + $type->get_message($value), + ); } sub clone_and_inherit_options{ my $self = shift; - my $name = shift; + my $args = $self->Mouse::Object::BUILDARGS(@_); - return ref($self)->new($name, %{$self}, (@_ == 1) ? %{$_[0]} : @_); + my($attribute_class, @traits) = ref($self)->interpolate_class($args); + + $args->{traits} = \@traits if @traits; + # do not inherit the 'handles' attribute + foreach my $name(keys %{$self}){ + if(!exists $args->{$name} && $name ne 'handles'){ + $args->{$name} = $self->{$name}; + } + } + + # remove temporary caches + foreach my $attr(keys %{$args}){ + if($attr =~ /\A _/xms){ + delete $args->{$attr}; + } + } + + return $attribute_class->new($self->name, $args); } -sub clone_parent { +sub clone_parent { # DEPRECATED my $self = shift; my $class = shift; my $name = shift; @@ -310,11 +219,10 @@ sub clone_parent { Carp::cluck("$self->clone_parent has been deprecated." . "Use \$meta->add_attribute and \$attr->install_accessors instead."); - $self->clone_and_inherited_args($class, $name, %args); } -sub get_parent_args { +sub get_parent_args { # DEPRECATED my $self = shift; my $class = shift; my $name = shift; @@ -328,18 +236,97 @@ sub get_parent_args { $self->throw_error("Could not find an attribute by the name of '$name' to inherit from"); } + +sub get_read_method { + return $_[0]->reader || $_[0]->accessor +} +sub get_write_method { + return $_[0]->writer || $_[0]->accessor +} + +sub _get_accessor_method_ref { + my($self, $type, $generator) = @_; + + my $metaclass = $self->associated_class + || $self->throw_error('No asocciated class for ' . $self->name); + + my $accessor = $self->$type(); + if($accessor){ + return $metaclass->get_method_body($accessor); + } + else{ + return $self->accessor_metaclass->$generator($self, $metaclass); + } +} + +sub get_read_method_ref{ + my($self) = @_; + return $self->{_read_method_ref} ||= $self->_get_accessor_method_ref('get_read_method', '_generate_reader'); +} + +sub get_write_method_ref{ + my($self) = @_; + return $self->{_write_method_ref} ||= $self->_get_accessor_method_ref('get_write_method', '_generate_writer'); +} + +sub set_value { + my($self, $object, $value) = @_; + return $self->get_write_method_ref()->($object, $value); +} + +sub get_value { + my($self, $object) = @_; + return $self->get_read_method_ref()->($object); +} + +sub has_value { + my($self, $object) = @_; + my $accessor_ref = $self->{_predicate_ref} + ||= $self->_get_accessor_method_ref('predicate', '_generate_predicate'); + + return $accessor_ref->($object); +} + +sub clear_value { + my($self, $object) = @_; + my $accessor_ref = $self->{_crealer_ref} + ||= $self->_get_accessor_method_ref('clearer', '_generate_clearer'); + + return $accessor_ref->($object); +} + + +sub associate_method{ + my ($attribute, $method_name) = @_; + $attribute->{associated_methods}++; + return; +} + sub install_accessors{ my($attribute) = @_; - my $metaclass = $attribute->{associated_class}; + my $metaclass = $attribute->associated_class; + my $accessor_class = $attribute->accessor_metaclass; - foreach my $type(qw(accessor reader writer predicate clearer handles)){ + foreach my $type(qw(accessor reader writer predicate clearer)){ if(exists $attribute->{$type}){ - my $installer = '_install_' . $type; + my $generator = '_generate_' . $type; + my $code = $accessor_class->$generator($attribute, $metaclass); + $metaclass->add_method($attribute->{$type} => $code); + $attribute->associate_method($attribute->{$type}); + } + } - Mouse::Meta::Method::Accessor->$installer($attribute, $attribute->{$type}, $metaclass); + # install delegation + if(exists $attribute->{handles}){ + my %handles = $attribute->_canonicalize_handles($attribute->{handles}); - $attribute->{associated_methods}++; + while(my($handle, $method_to_call) = each %handles){ + $metaclass->add_method($handle => + $attribute->_make_delegation_method( + $handle, $method_to_call)); + + $attribute->associate_method($handle); } } @@ -348,9 +335,53 @@ sub install_accessors{ $attribute->create($metaclass, $attribute->name, %{$attribute}); } + if(!$attribute->{associated_methods} && ($attribute->{is} || '') ne 'bare'){ + Carp::cluck( + 'Attribute (' . $attribute->name . ') of class ' . $metaclass->name + . ' has no associated methods (did you mean to provide an "is" argument?)'); + } + return; } +sub delegation_metaclass() { 'Mouse::Meta::Method::Delegation' } + +sub _canonicalize_handles { + my($self, $handles) = @_; + + if (ref($handles) eq 'HASH') { + return %$handles; + } + elsif (ref($handles) eq 'ARRAY') { + return map { $_ => $_ } @$handles; + } + elsif ( ref($handles) eq 'CODE' ) { + my $class_or_role = ( $self->{isa} || $self->{does} ) + || $self->throw_error( "Cannot find delegate metaclass for attribute " . $self->name ); + return $handles->( $self, Mouse::Meta::Class->initialize("$class_or_role")); + } + elsif (ref($handles) eq 'Regexp') { + my $class_or_role = ($self->{isa} || $self->{does}) + || $self->throw_error("Cannot delegate methods based on a Regexp without a type constraint (isa)"); + + my $meta = Mouse::Meta::Class->initialize("$class_or_role"); # "" for stringify + return map { $_ => $_ } + grep { !Mouse::Object->can($_) && $_ =~ $handles } + Mouse::Util::is_a_metarole($meta) + ? $meta->get_method_list + : $meta->get_all_method_names; + } + else { + $self->throw_error("Unable to canonicalize the 'handles' option with $handles"); + } +} + +sub _make_delegation_method { + my($self, $handle, $method_to_call) = @_; + return Mouse::Util::load_class($self->delegation_metaclass) + ->_generate_delegation($self, $handle, $method_to_call); +} + sub throw_error{ my $self = shift; @@ -359,12 +390,15 @@ sub throw_error{ } 1; - __END__ =head1 NAME -Mouse::Meta::Attribute - attribute metaclass +Mouse::Meta::Attribute - The Mouse attribute metaclass + +=head1 VERSION + +This document describes Mouse version 0.50_03 =head1 METHODS @@ -376,7 +410,7 @@ It adds the following options to the constructor: =over 4 -=item * C<< is => 'ro', 'rw', 'bare' >> +=item C<< 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 @@ -392,7 +426,7 @@ Use 'bare' when you are deliberately not installing any methods Moose will issue a deprecation warning when this attribute is added to a metaclass. -=item * C<< isa => Type >> +=item C<< 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 @@ -404,14 +438,14 @@ 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 * C<< does => Role >> +=item C<< does => Role >> This is short-hand for saying that the attribute's type must be an object which does the named role. B -=item * C<< coerce => Bool >> +=item C<< coerce => Bool >> This option is only valid for objects with a type constraint (C). If this is true, then coercions will be applied whenever @@ -419,12 +453,12 @@ this attribute is set. You can make both this and the C option true. -=item * C<< trigger => CodeRef >> +=item C<< trigger => CodeRef >> This option accepts a subroutine reference, which will be called after the attribute is set. -=item * C<< required => Bool >> +=item C<< 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, @@ -433,24 +467,24 @@ which will satisfy its required-ness. A required attribute must have a C, C or a non-C C -=item * C<< lazy => Bool >> +=item C<< 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 * C<< weak_ref => Bool >> +=item C<< weak_ref => Bool >> If this is true, the attribute's value will be stored as a weak reference. -=item * C<< auto_deref => Bool >> +=item C<< 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 * C<< lazy_build => Bool >> +=item C<< lazy_build => Bool >> Setting this to true makes the attribute lazy and provides a number of default methods. @@ -472,6 +506,13 @@ is equivalent to this: =back +=head2 C<< associate_method(MethodName) >> + +Associates a method with the attribute. Typically, this is called internally +when an attribute generates its accessors. + +Currently the argument I is ignored in Mouse. + =head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >> Checks that the given value passes this attribute's type constraint. Returns C @@ -479,12 +520,23 @@ on success, otherwise Ces. =head2 C<< clone_and_inherit_options(options) -> Mouse::Meta::Attribute >> -Creates a new attribute in OwnerClass, inheriting options from parent classes. +Creates a new attribute in the owner class, inheriting options from parent classes. Accessors and helper methods are installed. Some error checking is done. +=head2 C<< get_read_method_ref >> + +=head2 C<< get_write_method_ref >> + +Returns the subroutine reference of a method suitable for reading or +writing the attribute's value in the associated class. These methods +always return a subroutine reference, regardless of whether or not the +attribute is read- or write-only. + =head1 SEE ALSO L +L + =cut