X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMoose%2FMeta%2FAttribute.pm;h=1d304a823b62850ad56e8c20cb64a63b016cdcd4;hb=b805c70c24ed116e5900f563f4aa59f81b862059;hp=e441481cd830ac48b542289cb2a170ac0eae0f49;hpb=1a5632432dc07b9c1c07c6a29342f51172a6d439;p=gitmo%2FMoose.git diff --git a/lib/Moose/Meta/Attribute.pm b/lib/Moose/Meta/Attribute.pm index e441481..1d304a8 100644 --- a/lib/Moose/Meta/Attribute.pm +++ b/lib/Moose/Meta/Attribute.pm @@ -7,12 +7,19 @@ use warnings; use Scalar::Util 'blessed', 'weaken', 'reftype'; use Carp 'confess'; -our $VERSION = '0.05'; +our $VERSION = '0.06'; use Moose::Util::TypeConstraints (); use base 'Class::MOP::Attribute'; +# options which are not directly used +# but we store them for metadata purposes +__PACKAGE__->meta->add_attribute('isa' => (reader => '_isa_metadata')); +__PACKAGE__->meta->add_attribute('does' => (reader => '_does_metadata')); +__PACKAGE__->meta->add_attribute('is' => (reader => '_is_metadata')); + +# these are actual options for the attrs __PACKAGE__->meta->add_attribute('required' => (reader => 'is_required' )); __PACKAGE__->meta->add_attribute('lazy' => (reader => 'is_lazy' )); __PACKAGE__->meta->add_attribute('coerce' => (reader => 'should_coerce' )); @@ -26,11 +33,15 @@ __PACKAGE__->meta->add_attribute('trigger' => ( reader => 'trigger', predicate => 'has_trigger', )); +__PACKAGE__->meta->add_attribute('handles' => ( + reader => 'handles', + predicate => 'has_handles', +)); sub new { my ($class, $name, %options) = @_; $class->_process_options($name, \%options); - $class->SUPER::new($name, %options); + return $class->SUPER::new($name, %options); } sub clone_and_inherit_options { @@ -68,6 +79,7 @@ sub clone_and_inherit_options { sub _process_options { my ($class, $name, $options) = @_; + if (exists $options->{is}) { if ($options->{is} eq 'ro') { $options->{reader} = $name; @@ -75,10 +87,13 @@ sub _process_options { || confess "Cannot have a trigger on a read-only attribute"; } elsif ($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} = $name; + ((reftype($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} . ")" } } @@ -152,6 +167,13 @@ sub _process_options { 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}->name =~ /^ArrayRef|HashRef$/) + || confess "You cannot auto-dereference anything other than a ArrayRef or HashRef"; + } + if (exists $options->{lazy} && $options->{lazy}) { (exists $options->{default}) || confess "You cannot have lazy attribute without specifying a default value for it"; @@ -189,7 +211,7 @@ sub initialize_instance_slot { (defined($type_constraint->check($val))) || confess "Attribute (" . $self->name . - ") does not pass the type contraint (" . + ") does not pass the type constraint (" . $type_constraint->name . ") with '$val'"; } @@ -200,6 +222,8 @@ sub initialize_instance_slot { if ref $val && $self->is_weak_ref; } +## Accessor inline subroutines + sub _inline_check_constraint { my ($self, $value) = @_; return '' unless $self->has_type_constraint; @@ -207,12 +231,32 @@ sub _inline_check_constraint { # FIXME - remove 'unless defined($value) - constraint Undef return sprintf <<'EOF', $value, $value, $value, $value defined($attr->type_constraint->check(%s)) - || confess "Attribute (" . $attr->name . ") does not pass the type contraint (" + || confess "Attribute (" . $attr->name . ") does not pass the type constraint (" . $attr->type_constraint->name . ") with " . (defined(%s) ? "'%s'" : "undef") if defined(%s); EOF } +sub _inline_check_coercion { + my $self = shift; + return '' unless $self->should_coerce; + return 'my $val = $attr->type_constraint->coercion->coerce($_[1]);' +} + +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";' +} + +sub _inline_check_lazy { + my $self = shift; + return '' unless $self->is_lazy; + return '$_[0]->{$attr_name} = ($attr->has_default ? $attr->default($_[0]) : undef)' + . 'unless exists $_[0]->{$attr_name};'; +} + + sub _inline_store { my ($self, $instance, $value) = @_; @@ -245,15 +289,17 @@ sub _inline_auto_deref { return $ref_value unless $self->should_auto_deref; - my $type = eval { $self->type_constraint->name } || ''; - my $sigil; + my $type = $self->type_constraint->name; - if ( $type eq "ArrayRef" ) { + my $sigil; + if ($type eq "ArrayRef") { $sigil = '@'; - } elsif ( $type eq 'HashRef' ) { + } + elsif ($type eq 'HashRef') { $sigil = '%'; - } else { - confess "Can't auto deref unless type constraint is ArrayRef or HashRef"; + } + else { + confess "Can not auto de-reference the type constraint '$type'"; } "(wantarray() ? $sigil\{ ( $ref_value ) || return } : ( $ref_value ) )"; @@ -267,24 +313,16 @@ sub generate_accessor_method { my $inv = '$_[0]'; my $code = 'sub { ' . 'if (scalar(@_) == 2) {' - . ($attr->is_required ? - 'defined($_[1]) || confess "Attribute ($attr_name) is required, so cannot be set to undef";' - : '') - . ($attr->should_coerce ? - 'my $val = $attr->type_constraint->coercion->coerce($_[1]);' - : '') + . $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->is_lazy ? - '$_[0]->{$attr_name} = ($attr->has_default ? $attr->default($_[0]) : undef)' - . 'unless exists $_[0]->{$attr_name};' - : '') - . 'return ' . $attr->_inline_auto_deref( $attr->_inline_get( $inv ) ) + . $attr->_inline_check_lazy + . 'return ' . $attr->_inline_auto_deref($attr->_inline_get($inv)) . ' }'; my $sub = eval $code; - warn "Could not create accessor for '$attr_name' because $@ \n code: $code" if $@; confess "Could not create accessor for '$attr_name' because $@ \n code: $code" if $@; return $sub; } @@ -294,12 +332,8 @@ sub generate_writer_method { my $value_name = $attr->should_coerce ? '$val' : '$_[1]'; my $inv = '$_[0]'; my $code = 'sub { ' - . ($attr->is_required ? - 'defined($_[1]) || confess "Attribute ($attr_name) is required, so cannot be set to undef";' - : '') - . ($attr->should_coerce ? - 'my $val = $attr->type_constraint->coercion->coerce($_[1]);' - : '') + . $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) @@ -310,21 +344,129 @@ sub generate_writer_method { } sub generate_reader_method { - my $self = shift; - my $attr_name = $self->slots; + my $attr = shift; + my $attr_name = $attr->slots; my $code = 'sub {' . 'confess "Cannot assign a value to a read-only accessor" if @_ > 1;' - . ($self->is_lazy ? - '$_[0]->{$attr_name} = ($self->has_default ? $self->default($_[0]) : undef)' - . 'unless exists $_[0]->{$attr_name};' - : '') - . 'return ' . $self->_inline_auto_deref( '$_[0]->{$attr_name}' ) . ';' + . $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; } +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 { + # FIXME + # we should check for lack of + # a callable return value from + # the accessor here + ((shift)->$accessor_name())->$method_to_call(@_); + }); + } + } + } + + return; +} + +# private methods to help delegation ... + +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 (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 (my $role = $self->_does_metadata) { + # our role will always have + # a meta method + return $role->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__ @@ -357,8 +499,6 @@ will behave just as L does. =item B -=item B - =item B =item B @@ -367,15 +507,23 @@ will behave just as L does. =item B +=item B + =back =head2 Additional Moose features -Moose attributes support type-contstraint checking, weak reference +Moose attributes support type-constraint checking, weak reference creation and type coercion. =over 4 +=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 Returns true if this meta-attribute has a type constraint. @@ -386,6 +534,14 @@ 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. @@ -404,6 +560,14 @@ NOTE: lazy attributes, B have a C field set. Returns true if this meta-attribute should perform type coercion. +=item B + +Returns true if this meta-attribute should perform automatic +auto-dereferencing. + +NOTE: This can only be done for attributes whose type constraint is +either I or I. + =item B Returns true if this meta-attribute has a trigger set. @@ -427,6 +591,8 @@ to cpan-RT. Stevan Little Estevan@iinteractive.comE +Yuval Kogman Enothingmuch@woobling.comE + =head1 COPYRIGHT AND LICENSE Copyright 2006 by Infinity Interactive, Inc.