X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMoose%2FMeta%2FAttribute.pm;h=878f8cd54a1a988d95c6d647b79f128725668cab;hb=825a80dec36c7a359993cc8dc60af9463fdeb0c7;hp=f79b99b6ae7a50052dfbe625bef1de48be6bdf12;hpb=a15dff8d91efac7a8b88111afb27f284714018d1;p=gitmo%2FMoose.git diff --git a/lib/Moose/Meta/Attribute.pm b/lib/Moose/Meta/Attribute.pm index f79b99b..878f8cd 100644 --- a/lib/Moose/Meta/Attribute.pm +++ b/lib/Moose/Meta/Attribute.pm @@ -4,115 +4,503 @@ package Moose::Meta::Attribute; use strict; use warnings; -use Scalar::Util 'weaken', 'reftype'; +use Scalar::Util 'blessed', 'weaken', 'reftype'; use Carp 'confess'; -use Moose::Util::TypeConstraints ':no_export'; +our $VERSION = '0.08'; -our $VERSION = '0.01'; +use Moose::Util::TypeConstraints (); use base 'Class::MOP::Attribute'; -Moose::Meta::Attribute->meta->add_attribute( - Class::MOP::Attribute->new('weak_ref' => ( - reader => 'weak_ref', - predicate => { - 'has_weak_ref' => sub { $_[0]->weak_ref() ? 1 : 0 } - } - )) -); - -Moose::Meta::Attribute->meta->add_attribute( - Class::MOP::Attribute->new('type_constraint' => ( - reader => 'type_constraint', - predicate => 'has_type_constraint', - )) -); - -Moose::Meta::Attribute->meta->add_before_method_modifier('new' => sub { - my (undef, undef, %options) = @_; - (reftype($options{type_constraint}) && reftype($options{type_constraint}) eq 'CODE') - || confess "Type cosntraint parameter must be a code-ref"; -}); +# options which are not directly used +# but we store them for metadata purposes +__PACKAGE__->meta->add_attribute('isa' => (reader => '_isa_metadata')); +__PACKAGE__->meta->add_attribute('does' => (reader => '_does_metadata')); +__PACKAGE__->meta->add_attribute('is' => (reader => '_is_metadata')); + +# these are actual options for the attrs +__PACKAGE__->meta->add_attribute('required' => (reader => 'is_required' )); +__PACKAGE__->meta->add_attribute('lazy' => (reader => 'is_lazy' )); +__PACKAGE__->meta->add_attribute('coerce' => (reader => 'should_coerce' )); +__PACKAGE__->meta->add_attribute('weak_ref' => (reader => 'is_weak_ref' )); +__PACKAGE__->meta->add_attribute('auto_deref' => (reader => 'should_auto_deref')); +__PACKAGE__->meta->add_attribute('type_constraint' => ( + reader => 'type_constraint', + predicate => 'has_type_constraint', +)); +__PACKAGE__->meta->add_attribute('trigger' => ( + reader => 'trigger', + predicate => 'has_trigger', +)); +__PACKAGE__->meta->add_attribute('handles' => ( + reader => 'handles', + predicate => 'has_handles', +)); + +sub new { + my ($class, $name, %options) = @_; + $class->_process_options($name, \%options); + return $class->SUPER::new($name, %options); +} -sub generate_accessor_method { - my ($self, $attr_name) = @_; - if ($self->has_type_constraint) { - if ($self->has_weak_ref) { - return sub { - if (scalar(@_) == 2) { - (defined $self->type_constraint->($_[1])) - || confess "Attribute ($attr_name) does not pass the type contraint" - if defined $_[1]; - $_[0]->{$attr_name} = $_[1]; - weaken($_[0]->{$attr_name}); - } - $_[0]->{$attr_name}; - }; - } +sub clone_and_inherit_options { + my ($self, %options) = @_; + # you can change default, required and coerce + my %actual_options; + foreach my $legal_option (qw(default coerce required)) { + if (exists $options{$legal_option}) { + $actual_options{$legal_option} = $options{$legal_option}; + delete $options{$legal_option}; + } + } + # isa can be changed, but only if the + # new type is a subtype + if ($options{isa}) { + my $type_constraint; + if (blessed($options{isa}) && $options{isa}->isa('Moose::Meta::TypeConstraint')) { + $type_constraint = $options{isa}; + } else { - return sub { - if (scalar(@_) == 2) { - (defined $self->type_constraint->($_[1])) - || confess "Attribute ($attr_name) does not pass the type contraint" - if defined $_[1]; - $_[0]->{$attr_name} = $_[1]; - } - $_[0]->{$attr_name}; - }; - } - } - else { - if ($self->has_weak_ref) { - return sub { - if (scalar(@_) == 2) { - $_[0]->{$attr_name} = $_[1]; - weaken($_[0]->{$attr_name}); - } - $_[0]->{$attr_name}; - }; - } - else { - sub { - $_[0]->{$attr_name} = $_[1] if scalar(@_) == 2; - $_[0]->{$attr_name}; - }; + $type_constraint = Moose::Util::TypeConstraints::find_type_constraint($options{isa}); + (defined $type_constraint) + || confess "Could not find the type constraint '" . $options{isa} . "'"; } - } + # NOTE: + # check here to see if the new type + # is a subtype of the old one + ($type_constraint->is_subtype_of($self->type_constraint->name)) + || confess "New type constraint setting must be a subtype of inherited one" + # iff we have a type constraint that is ... + if $self->has_type_constraint; + # then we use it :) + $actual_options{type_constraint} = $type_constraint; + delete $options{isa}; + } + (scalar keys %options == 0) + || confess "Illegal inherited options => (" . (join ', ' => keys %options) . ")"; + $self->clone(%actual_options); } -sub generate_writer_method { - my ($self, $attr_name) = @_; - if ($self->has_type_constraint) { - if ($self->has_weak_ref) { - return sub { - (defined $self->type_constraint->($_[1])) - || confess "Attribute ($attr_name) does not pass the type contraint" - if defined $_[1]; - $_[0]->{$attr_name} = $_[1]; - weaken($_[0]->{$attr_name}); - }; +sub _process_options { + my ($class, $name, $options) = @_; + + if (exists $options->{is}) { + if ($options->{is} eq 'ro') { + $options->{reader} = $name; + (!exists $options->{trigger}) + || confess "Cannot have a trigger on a read-only attribute"; } - else { - return sub { - (defined $self->type_constraint->($_[1])) - || confess "Attribute ($attr_name) does not pass the type contraint" - if defined $_[1]; - $_[0]->{$attr_name} = $_[1]; - }; + elsif ($options->{is} eq 'rw') { + $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 => " . $options->{is} . ")" + } } - else { - if ($self->has_weak_ref) { - return sub { - $_[0]->{$attr_name} = $_[1]; - weaken($_[0]->{$attr_name}); - }; + + if (exists $options->{isa}) { + + if (exists $options->{does}) { + if (eval { $options->{isa}->can('does') }) { + ($options->{isa}->does($options->{does})) + || confess "Cannot have an isa option and a does option if the isa does not do the does"; + } + else { + confess "Cannot have an isa option which cannot ->does()"; + } + } + + # allow for anon-subtypes here ... + if (blessed($options->{isa}) && $options->{isa}->isa('Moose::Meta::TypeConstraint')) { + $options->{type_constraint} = $options->{isa}; } else { - return sub { $_[0]->{$attr_name} = $_[1] }; + + if ($options->{isa} =~ /\|/) { + my @type_constraints = split /\s*\|\s*/ => $options->{isa}; + $options->{type_constraint} = Moose::Util::TypeConstraints::create_type_constraint_union( + @type_constraints + ); + } + else { + # otherwise assume it is a constraint + my $constraint = Moose::Util::TypeConstraints::find_type_constraint($options->{isa}); + # if the constraing it not found .... + unless (defined $constraint) { + # assume it is a foreign class, and make + # an anon constraint for it + $constraint = Moose::Util::TypeConstraints::subtype( + 'Object', + Moose::Util::TypeConstraints::where { $_->isa($options->{isa}) } + ); + } + $options->{type_constraint} = $constraint; + } + } + } + elsif (exists $options->{does}) { + # allow for anon-subtypes here ... + if (blessed($options->{does}) && $options->{does}->isa('Moose::Meta::TypeConstraint')) { + $options->{type_constraint} = $options->{isa}; } + else { + # otherwise assume it is a constraint + my $constraint = Moose::Util::TypeConstraints::find_type_constraint($options->{does}); + # if the constraing it not found .... + unless (defined $constraint) { + # assume it is a foreign class, and make + # an anon constraint for it + $constraint = Moose::Util::TypeConstraints::subtype( + 'Role', + Moose::Util::TypeConstraints::where { $_->does($options->{does}) } + ); + } + $options->{type_constraint} = $constraint; + } + } + + if (exists $options->{coerce} && $options->{coerce}) { + (exists $options->{type_constraint}) + || confess "You cannot have coercion without specifying a type constraint"; + confess "You cannot have a weak reference to a coerced value" + 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}->is_a_type_of('ArrayRef') || + $options->{type_constraint}->is_a_type_of('HashRef')) + || confess "You cannot auto-dereference anything other than a ArrayRef or HashRef"; + } + + if (exists $options->{lazy} && $options->{lazy}) { + (exists $options->{default}) + || confess "You cannot have lazy attribute without specifying a default value for it"; + } +} + +sub initialize_instance_slot { + my ($self, $meta_instance, $instance, $params) = @_; + my $init_arg = $self->init_arg(); + # try to fetch the init arg from the %params ... + + my $val; + if (exists $params->{$init_arg}) { + $val = $params->{$init_arg}; + } + else { + # skip it if it's lazy + return if $self->is_lazy; + # and die if it's required and doesn't have a default value + confess "Attribute (" . $self->name . ") is required" + if $self->is_required && !$self->has_default; + } + + # if nothing was in the %params, we can use the + # attribute's default value (if it has one) + if (!defined $val && $self->has_default) { + $val = $self->default($instance); + } + if (defined $val) { + if ($self->has_type_constraint) { + my $type_constraint = $self->type_constraint; + if ($self->should_coerce && $type_constraint->has_coercion) { + $val = $type_constraint->coerce($val); + } + (defined($type_constraint->check($val))) + || confess "Attribute (" . + $self->name . + ") does not pass the type constraint (" . + $type_constraint->name . + ") with '$val'"; + } } + + $meta_instance->set_slot_value($instance, $self->name, $val); + $meta_instance->weaken_slot_value($instance, $self->name) + if ref $val && $self->is_weak_ref; +} + +## Accessor inline subroutines + +sub _inline_check_constraint { + my ($self, $value) = @_; + return '' unless $self->has_type_constraint; + + # FIXME - remove 'unless defined($value) - constraint Undef + return sprintf <<'EOF', $value, $value, $value, $value +defined($type_constraint->(%s)) + || 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 = $attr->type_constraint->coerce($_[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 $self->is_lazy; + if ($self->has_type_constraint) { + # NOTE: + # this could probably be cleaned + # up and streamlined a little more + return 'unless (exists $_[0]->{$attr_name}) {' . + ' if ($attr->has_default) {' . + ' my $default = $attr->default($_[0]);' . + ' (defined($type_constraint->($default)))' . + ' || confess "Attribute (" . $attr->name . ") does not pass the type constraint ("' . + ' . $attr->type_constraint->name . ") with " . (defined($default) ? "\'$default\'" : "undef")' . + ' if defined($default);' . + ' $_[0]->{$attr_name} = $default; ' . + ' }' . + ' else {' . + ' $_[0]->{$attr_name} = undef;' . + ' }' . + '}'; + } + return '$_[0]->{$attr_name} = ($attr->has_default ? $attr->default($_[0]) : undef)' + . 'unless exists $_[0]->{$attr_name};'; +} + + +sub _inline_store { + my ($self, $instance, $value) = @_; + + my $mi = $self->associated_class->get_meta_instance; + my $slot_name = sprintf "'%s'", $self->slots; + + my $code = $mi->inline_set_slot_value($instance, $slot_name, $value) . ";"; + $code .= $mi->inline_weaken_slot_value($instance, $slot_name, $value) . ";" + if $self->is_weak_ref; + return $code; +} + +sub _inline_trigger { + my ($self, $instance, $value) = @_; + return '' unless $self->has_trigger; + return sprintf('$attr->trigger->(%s, %s, $attr);', $instance, $value); +} + +sub _inline_get { + my ($self, $instance) = @_; + + my $mi = $self->associated_class->get_meta_instance; + my $slot_name = sprintf "'%s'", $self->slots; + + return $mi->inline_get_slot_value($instance, $slot_name); +} + +sub _inline_auto_deref { + my ( $self, $ref_value ) = @_; + + return $ref_value unless $self->should_auto_deref; + + my $type_constraint = $self->type_constraint; + + my $sigil; + if ($type_constraint->is_a_type_of('ArrayRef')) { + $sigil = '@'; + } + elsif ($type_constraint->is_a_type_of('HashRef')) { + $sigil = '%'; + } + else { + confess "Can not auto de-reference the type constraint '" . $type_constraint->name . "'"; + } + + "(wantarray() ? $sigil\{ ( $ref_value ) || return } : ( $ref_value ) )"; +} + +sub generate_accessor_method { + my ($attr, $attr_name) = @_; + my $value_name = $attr->should_coerce ? '$val' : '$_[1]'; + my $mi = $attr->associated_class->get_meta_instance; + my $slot_name = sprintf "'%s'", $attr->slots; + my $inv = '$_[0]'; + my $code = 'sub { ' + . 'if (scalar(@_) == 2) {' + . $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->_inline_check_lazy + . 'return ' . $attr->_inline_auto_deref($attr->_inline_get($inv)) + . ' }'; + + # NOTE: + # set up the environment + my $type_constraint = $attr->type_constraint + ? $attr->type_constraint->_compiled_type_constraint + : undef; + + my $sub = eval $code; + confess "Could not create accessor for '$attr_name' because $@ \n code: $code" if $@; + return $sub; +} + +sub generate_writer_method { + my ($attr, $attr_name) = @_; + my $value_name = $attr->should_coerce ? '$val' : '$_[1]'; + my $inv = '$_[0]'; + my $code = 'sub { ' + . $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) + . ' }'; + + # NOTE: + # set up the environment + my $type_constraint = $attr->type_constraint + ? $attr->type_constraint->_compiled_type_constraint + : undef; + + my $sub = eval $code; + confess "Could not create writer for '$attr_name' because $@ \n code: $code" if $@; + return $sub; +} + +sub generate_reader_method { + my $attr = shift; + my $attr_name = $attr->slots; + my $code = 'sub {' + . 'confess "Cannot assign a value to a read-only accessor" if @_ > 1;' + . $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} } # NOTE: !never! delegate &meta + grep { $_->{class} ne 'Moose::Object' && $_->{name} ne 'meta' } + $meta->compute_all_applicable_methods; + } + elsif ($meta->isa('Moose::Meta::Role')) { + return $meta->get_method_list; + } + else { + confess "Unable to recognize the delegate metaclass '$meta'"; + } } 1; @@ -123,33 +511,109 @@ __END__ =head1 NAME -Moose::Meta::Attribute - - -=head1 SYNOPSIS +Moose::Meta::Attribute - The Moose attribute metaclass =head1 DESCRIPTION +This is a subclass of L with Moose specific +extensions. + +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 METHODS +=head2 Overridden methods + +These methods override methods in L and add +Moose specific features. You can safely assume though that they +will behave just as L does. + =over 4 =item B +=item B + =item B =item B +=item B + +=item B + =back +=head2 Additional Moose features + +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. + =item B -=item B +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. + +=item B + +Returns true if this meta-attribute is required to have a value. + +=item B + +Returns true if this meta-attribute should be initialized lazily. + +NOTE: lazy attributes, B have a C field set. -=item B +=item B + +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. + +=item B + +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. =back @@ -159,17 +623,12 @@ All complex software has bugs lurking in it, and this module is no exception. If you find a bug please either email me, or add the bug to cpan-RT. -=head1 CODE COVERAGE - -I use L to test the code coverage of my tests, below is the -L report on this module's test suite. - -=head1 ACKNOWLEDGEMENTS - =head1 AUTHOR Stevan Little Estevan@iinteractive.comE +Yuval Kogman Enothingmuch@woobling.comE + =head1 COPYRIGHT AND LICENSE Copyright 2006 by Infinity Interactive, Inc. @@ -179,4 +638,4 @@ L This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. -=cut \ No newline at end of file +=cut