X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMoose%2FMeta%2FAttribute.pm;h=14036a16b41b51d6f605788f28db7609959fa2dd;hb=452bac1b88c2bc806fbe285146d050c73e2119b7;hp=505c0f75d94b648d11b4ce26401850abf26c0b06;hpb=536f0b1739154330082a42ba0c096d9d43cdc134;p=gitmo%2FMoose.git diff --git a/lib/Moose/Meta/Attribute.pm b/lib/Moose/Meta/Attribute.pm index 505c0f7..14036a1 100644 --- a/lib/Moose/Meta/Attribute.pm +++ b/lib/Moose/Meta/Attribute.pm @@ -13,6 +13,22 @@ use Moose::Util::TypeConstraints (); use base 'Class::MOP::Attribute'; +# options which are not directly used +# but we store them for metadata purposes +__PACKAGE__->meta->add_attribute('isa' => ( + reader => 'isa_metadata', + predicate => 'has_isa_metadata', +)); +__PACKAGE__->meta->add_attribute('does' => ( + reader => 'does_metadata', + predicate => 'has_does_metadata', +)); +__PACKAGE__->meta->add_attribute('is' => ( + reader => 'is_metadata', + predicate => 'has_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('coerce' => (reader => 'should_coerce' )); @@ -26,11 +42,16 @@ __PACKAGE__->meta->add_attribute('trigger' => ( reader => 'trigger', predicate => 'has_trigger', )); +__PACKAGE__->meta->add_attribute('handles' => ( + reader => 'handles', + predicate => 'has_handles', +)); sub new { my ($class, $name, %options) = @_; $class->_process_options($name, \%options); - $class->SUPER::new($name, %options); + my $self = $class->SUPER::new($name, %options); + return $self; } sub clone_and_inherit_options { @@ -68,6 +89,7 @@ sub clone_and_inherit_options { sub _process_options { my ($class, $name, $options) = @_; + if (exists $options->{is}) { if ($options->{is} eq 'ro') { $options->{reader} = $name; @@ -75,13 +97,16 @@ sub _process_options { || confess "Cannot have a trigger on a read-only attribute"; } elsif ($options->{is} eq 'rw') { - $options->{accessor} = $name; - ((reftype($options->{trigger}) || '') eq 'CODE') - || confess "A trigger must be a CODE reference" - if exists $options->{trigger}; + $options->{accessor} = $name; + } + else { + confess "I do not understand this option (is => " . $options->{is} . ")" } } + # process and check trigger here ... + + if (exists $options->{isa}) { if (exists $options->{does}) { @@ -334,6 +359,112 @@ sub generate_reader_method { return $sub; } +sub install_accessors { + 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 { + ((shift)->$accessor_name())->$method_to_call(@_); + }); + } + } + } + + return; +} + +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); + } + else { + confess "Unable to canonicalize the 'handles' option with $handles"; + } +} + +sub _find_delegate_metaclass { + my $self = shift; + if ($self->has_isa_metadata) { + my $class = $self->isa_metadata; + # if the class does have + # a meta method, use it + return $class->meta if $class->can('meta'); + # otherwise we might be + # dealing with a non-Moose + # class, and need to make + # our own metaclass + return Moose::Meta::Class->initialize($class); + } + elsif ($self->has_does_metadata) { + # our role will always have + # a meta method + return $self->does_metadata->meta; + } + else { + confess "Cannot find delegate metaclass for attribute " . $self->name; + } +} + +sub _get_delegate_method_list { + my $self = shift; + my $meta = $self->_find_delegate_metaclass; + if ($meta->isa('Class::MOP::Class')) { + return map { $_->{name} } + grep { $_->{class} ne 'Moose::Object' } + $meta->compute_all_applicable_methods; + } + elsif ($meta->isa('Moose::Meta::Role')) { + return $meta->get_method_list; + } + else { + confess "Unable to recognize the delegate metaclass '$meta'"; + } +} + 1; __END__ @@ -376,6 +507,8 @@ will behave just as L does. =item B +=item B + =back =head2 Additional Moose features @@ -395,6 +528,14 @@ 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 + +Returns true if this meta-attribute performs delegation. + +=item B + +This returns the value which was passed into the handles option. + =item B Returns true if this meta-attribute produces a weak reference.