use Scalar::Util 'blessed', 'weaken';
use overload ();
-our $VERSION = '0.65';
+our $VERSION = '0.75_01';
our $AUTHORITY = 'cpan:STEVAN';
use Moose::Meta::Method::Accessor;
documentation lazy handles
builder type_constraint
definition_context
+ lazy_build
);
sub legal_options_for_inheritance { @legal_options_for_inheritance }
my $class = $params{metaclass} || ref $self;
- if ( 0 and $class eq ref $self ) {
- return $self->SUPER::clone(%params);
- } else {
- my ( @init, @non_init );
+ 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 $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 {
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)
}
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);
};
$self->throw_error("Attribute ($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;
}
if ($self->has_trigger) {
- $self->trigger->($instance, $value, $self);
+ $self->trigger->($instance, $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, $value);
}
}
}
}
else {
- Class::MOP::load_class($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,
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);
);
}
+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;
=head1 DESCRIPTION
-This is a subclass of L<Class::MOP::Attribute> with Moose specific
-extensions.
+This class is a subclass of L<Class::MOP::Attribute> that provides
+additional Moose-specific functionality.
+
+To really understand this class, you will need to start with the
+L<Class::MOP::Attribute> 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<Class::MOP::Attribute> documentation.
+C<Moose::Meta::Attribute> is a subclass of L<Class::MOP::Attribute>.
=head1 METHODS
-=head2 Overridden methods
+Many of the documented below override methods in
+L<Class::MOP::Attribute> and add Moose specific features.
-These methods override methods in L<Class::MOP::Attribute> and add
-Moose specific features. You can safely assume though that they
-will behave just as L<Class::MOP::Attribute> does.
+=head2 Creation
=over 4
-=item B<new>
+=item B<< Moose::Meta::Attribute->new(%options) >>
+
+This method overrides the L<Class::MOP::Attribute> constructor.
+
+Many of the options below are described in more detail in the
+L<Moose::Manual::Attributes> document.
+
+It adds the following options to the constructor:
+
+=over 8
+
+=item * is => 'ro' or 'rw'
+
+This provides a shorthand for specifying the C<reader>, C<writer>, or
+C<accessor> names. If the attribute is read-only ('ro') then it will
+have a C<reader> method with the same attribute as the name.
+
+If it is read-write ('rw') then it will have an C<accessor> method
+with the same name. If you provide an explicit C<writer> for a
+read-write attribute, then you will have a C<reader> with the same
+name as the attribute, and a C<writer> with the name you provided.
+
+=item * 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
+name.
+
+This option can also accept a L<Moose::Meta::TypeConstraint> object.
+
+If you I<also> provide a C<does> option, then your C<isa> option must
+be a class name, and that class must do the role specified with
+C<does>.
+
+=item * does => $role
+
+This is short-hand for saying that the attribute's type must be an
+object which does the named role.
-=item B<clone>
+=item * coerce => $bool
-=item B<does>
+This option is only valid for objects with a type constraint
+(C<isa>). If this is true, then coercions will be applied whenever
+this attribute is set.
-=item B<initialize_instance_slot>
+You can make both this and the C<weak_ref> option true.
-=item B<install_accessors>
+=item * trigger => $sub
-=item B<remove_accessors>
+This option accepts a subroutine reference, which will be called after
+the attribute is set.
-=item B<install_delegation>
+=item * required => $bool
-=item B<remove_delegation>
+An attribute which is required must be provided to the constructor. An
+attribute which is required can also have a C<default> or C<builder>,
+which will satisfy its required-ness.
-=item B<accessor_metaclass>
+A required attribute must have a C<default>, C<builder> or a
+non-C<undef> C<init_arg>
-=item B<delegation_metaclass>
+=item * lazy => $bool
+
+A lazy attribute must have a C<default> or C<builder>. 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<name> option to provide a new name for the attribute.
+
+The C<%options> can only specify options handled by
+L<Class::MOP::Attribute>.
+
+=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<Class::MOP::Attribute> method to handle lazy
+attributes, weak references, and type constraints.
=item B<get_value>
=item B<set_value>
- eval { $point->meta->get_attribute('x')->set_value($point, 'fourty-two') };
+ eval { $point->meta->get_attribute('x')->set_value($point, 'forty-two') };
if($@) {
print "Oops: $@\n";
}
-I<Attribute (x) does not pass the type constraint (Int) with 'fourty-two'>
+I<Attribute (x) does not pass the type constraint (Int) with 'forty-two'>
Before setting the value, a check is made on the type constraint of
the attribute, if it has one, to see if the value passes it. If the
=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<Moose::Meta::Method::Accessor>.
+
+=item B<< $attr->delegation_metaclass >>
+
+Returns the delegation metaclass name, which defaults to
+L<Moose::Meta::Method::Delegation>.
+
+=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<throw_error>
+=item B<< $attr->does($role) >>
-Delegates to C<associated_class> or C<Moose::Meta::Class> if there is none.
+This indicates whether the I<attribute itself> does the given
+role. The role can be given as a full class name, or as a resolvable
+trait name.
-=item B<interpolate_class_and_new>
+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<interpolate_class>
+=item B<< Moose::Meta::Class->interpolate_class_and_new($name, %options) >>
-When called as a class method causes interpretation of the C<metaclass> and
+This is an alternate constructor that handles the C<metaclass> and
C<traits> options.
-=item B<clone_and_inherit_options>
-
-This is to support the C<has '+foo'> feature, it clones an attribute
-from a superclass and allows a very specific set of changes to be made
-to the attribute.
-
-=item B<legal_options_for_inheritance>
+Effectively, this method is a factory that finds or creates the
+appropriate class for the given C<metaclass> and/or C<traits>.
-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<has_type_constraint>
+=item B<< $attr->clone_and_inherit_options(%options) >>
-Returns true if this meta-attribute has a type constraint.
+This method supports the C<has '+foo'> feature. It does various bits
+of processing on the supplied C<%options> before ultimately calling
+the C<clone> method.
-=item B<type_constraint>
+One of its main tasks is to make sure that the C<%options> provided
+only includes the options returned by the
+C<legal_options_for_inheritance> 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<Moose::Meta::TypeConstraint>.
+=item B<< $attr->legal_options_for_inheritance >>
-=item B<verify_against_type_constraint>
+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<has_handles>
+=item B<< $attr->type_constraint >>
-Returns true if this meta-attribute performs delegation.
+Returns the L<Moose::Meta::TypeConstraint> object for this attribute,
+if it has one.
-=item B<handles>
+=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<is_weak_ref>
+=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<is_required>
+=item B<< $attr->handles >>
-Returns true if this meta-attribute is required to have a value.
+This returns the value of the C<handles> option passed to the
+constructor.
-=item B<is_lazy>
+=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<must> have a C<default> or C<builder> field set.
+=item B<< $attr->is_weak_ref >>
-=item B<is_lazy_build>
+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<lazy_build =E<gt> 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<builder> is that the C<builder>
-method is a private method while the C<clearer> and C<predicate> 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<should_coerce>
+Returns true if the C<lazy_build> 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<should_auto_deref>
+Returns true if the C<coerce> 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<ArrayRef> or I<HashRef>.
+Returns true if the C<auto_deref> option passed to the constructor was
+true.
-=item B<has_trigger>
+=item B<< $attr->trigger >>
-Returns true if this meta-attribute has a trigger set.
+This is the subroutine reference that was in the C<trigger> option
+passed to the constructor, if any.
-=item B<trigger>
+=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<basic>
-bi-directional relations.
+Returns true if this attribute has a trigger set.
-=item B<documentation>
+=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<documentation> option passed to
+the constructor, if any.
-=item B<has_documentation>
+=item B<< $attr->has_documentation >>
-Returns true if this meta-attribute has any documentation.
+Returns true if this attribute has any documentation.
-=item B<applied_traits>
+=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<undef>.
+This returns an array reference of all the traits which were applied
+to this attribute. If none were applied, this returns C<undef>.
-=item B<has_applied_traits>
+=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
=head1 COPYRIGHT AND LICENSE
-Copyright 2006-2008 by Infinity Interactive, Inc.
+Copyright 2006-2009 by Infinity Interactive, Inc.
L<http://www.iinteractive.com>
projects / gitmo/Moose.git / blobdiff