use Scalar::Util 'blessed', 'weaken', 'reftype';
use Carp 'confess';
+use Sub::Name 'subname';
+use overload ();
-our $VERSION = '0.10';
+our $VERSION = '0.22';
our $AUTHORITY = 'cpan:STEVAN';
use Moose::Meta::Method::Accessor;
+use Moose::Util ();
use Moose::Util::TypeConstraints ();
use base 'Class::MOP::Attribute';
# these are actual options for the attrs
__PACKAGE__->meta->add_attribute('required' => (reader => 'is_required' ));
__PACKAGE__->meta->add_attribute('lazy' => (reader => 'is_lazy' ));
+__PACKAGE__->meta->add_attribute('lazy_build' => (reader => 'is_lazy_build' ));
__PACKAGE__->meta->add_attribute('coerce' => (reader => 'should_coerce' ));
__PACKAGE__->meta->add_attribute('weak_ref' => (reader => 'is_weak_ref' ));
__PACKAGE__->meta->add_attribute('auto_deref' => (reader => 'should_auto_deref'));
reader => 'documentation',
predicate => 'has_documentation',
));
+__PACKAGE__->meta->add_attribute('traits' => (
+ reader => 'applied_traits',
+ predicate => 'has_applied_traits',
+));
+
+# NOTE:
+# we need to have a ->does method in here to
+# more easily support traits, and the introspection
+# of those traits. So in order to do this we
+# just alias Moose::Object's version of it.
+# - SL
+*does = \&Moose::Object::does;
sub new {
- my ($class, $name, %options) = @_;
- $class->_process_options($name, \%options);
- return $class->SUPER::new($name, %options);
+ my ($class, $name, %options) = @_;
+ $class->_process_options($name, \%options);
+ return $class->SUPER::new($name, %options);
+}
+
+sub interpolate_class_and_new {
+ my ($class, $name, @args) = @_;
+
+ $class->interpolate_class(@args)->new($name, @args);
+}
+
+sub interpolate_class {
+ my ($class, %options) = @_;
+
+ if ( my $metaclass_name = $options{metaclass} ) {
+ $class = Moose::Util::resolve_metaclass_alias( Attribute => $metaclass_name );
+ }
+
+ if (my $traits = $options{traits}) {
+ my @traits = map {
+ Moose::Util::resolve_metatrait_alias( Attribute => $_ )
+ or
+ $_
+ } @$traits;
+
+ my $anon_class = Moose::Meta::Class->create_anon_class(
+ superclasses => [ $class ],
+ roles => [ @traits ],
+ cache => 1,
+ );
+
+ return $anon_class->name;
+ }
+ else {
+ return $class;
+ }
}
sub clone_and_inherit_options {
my ($self, %options) = @_;
- # you can change default, required, coerce and documentation
+ # you can change default, required, coerce, documentation, lazy, handles, builder, metaclass and traits
my %actual_options;
- foreach my $legal_option (qw(default coerce required documentation)) {
+ foreach my $legal_option (qw(default coerce required documentation lazy handles builder metaclass traits)) {
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 {
- $type_constraint = Moose::Util::TypeConstraints::find_type_constraint($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} = $type_constraint;
+ if (blessed($options{isa}) && $options{isa}->isa('Moose::Meta::TypeConstraint')) {
+ $type_constraint = $options{isa};
+ }
+ else {
+ $type_constraint = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa});
+ (defined $type_constraint)
+ || confess "Could not find the type constraint '" . $options{isa} . "'";
+ }
+
+ $actual_options{type_constraint} = $type_constraint;
delete $options{isa};
}
- (scalar keys %options == 0)
+
+ if ($options{does}) {
+ my $type_constraint;
+ if (blessed($options{does}) && $options{does}->isa('Moose::Meta::TypeConstraint')) {
+ $type_constraint = $options{does};
+ }
+ else {
+ $type_constraint = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options{does});
+ (defined $type_constraint)
+ || confess "Could not find the type constraint '" . $options{does} . "'";
+ }
+
+ $actual_options{type_constraint} = $type_constraint;
+ delete $options{does};
+ }
+
+ (scalar keys %options == 0)
|| confess "Illegal inherited options => (" . (join ', ' => keys %options) . ")";
$self->clone(%actual_options);
}
sub _process_options {
my ($class, $name, $options) = @_;
-
- if (exists $options->{is}) {
- if ($options->{is} eq 'ro') {
- $options->{reader} = $name;
- (!exists $options->{trigger})
- || confess "Cannot have a trigger on a read-only attribute";
- }
- elsif ($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} . ")"
- }
- }
-
- 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} = $options->{isa};
- }
- else {
-
- if ($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;
+
+ 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 $name";
+ }
+ elsif ($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} . ") on attribute $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 on attribute $name";
+ }
+ else {
+ confess "Cannot have an isa option which cannot ->does() on attribute $name";
}
- }
- }
- 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') ||
+ }
+
+ # allow for anon-subtypes here ...
+ if (blessed($options->{isa}) && $options->{isa}->isa('Moose::Meta::TypeConstraint')) {
+ $options->{type_constraint} = $options->{isa};
+ }
+ else {
+ $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options->{isa});
+ }
+ }
+ elsif (exists $options->{does}) {
+ # allow for anon-subtypes here ...
+ if (blessed($options->{does}) && $options->{does}->isa('Moose::Meta::TypeConstraint')) {
+ $options->{type_constraint} = $options->{does};
+ }
+ else {
+ $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options->{does});
+ }
+ }
+
+ if (exists $options->{coerce} && $options->{coerce}) {
+ (exists $options->{type_constraint})
+ || confess "You cannot have coercion without specifying a type constraint on attribute $name";
+ confess "You cannot have a weak reference to a coerced value on attribute $name"
+ 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 on attribute $name";
+ ($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";
- }
+ || confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute $name";
+ }
+
+ if (exists $options->{lazy_build} && $options->{lazy_build} == 1) {
+ confess("You can not use lazy_build and default for the same attribute $name")
+ if exists $options->{default};
+ $options->{lazy} = 1;
+ $options->{required} = 1;
+ $options->{builder} ||= "_build_${name}";
+ if ($name =~ /^_/) {
+ $options->{clearer} ||= "_clear${name}";
+ $options->{predicate} ||= "_has${name}";
+ }
+ else {
+ $options->{clearer} ||= "clear_${name}";
+ $options->{predicate} ||= "has_${name}";
+ }
+ }
+
+ if (exists $options->{lazy} && $options->{lazy}) {
+ (exists $options->{default} || defined $options->{builder} )
+ || confess "You cannot have lazy attribute ($name) without specifying a default value for it";
+ }
+
+ if ( $options->{required} && !( ( !exists $options->{init_arg} || defined $options->{init_arg} ) || exists $options->{default} || defined $options->{builder} ) ) {
+ confess "You cannot have a required attribute ($name) without a default, builder, or an init_arg";
+ }
+
}
sub initialize_instance_slot {
my $init_arg = $self->init_arg();
# try to fetch the init arg from the %params ...
- my $val;
- if (exists $params->{$init_arg}) {
+ my $val;
+ my $value_is_set;
+ if ( defined($init_arg) and exists $params->{$init_arg}) {
$val = $params->{$init_arg};
+ $value_is_set = 1;
}
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;
+ confess "Attribute (" . $self->name . ") is required"
+ if $self->is_required && !$self->has_default && !$self->has_builder;
+
+ # if nothing was in the %params, we can use the
+ # attribute's default value (if it has one)
+ if ($self->has_default) {
+ $val = $self->default($instance);
+ $value_is_set = 1;
+ }
+ elsif ($self->has_builder) {
+ if (my $builder = $instance->can($self->builder)){
+ $val = $instance->$builder;
+ $value_is_set = 1;
+ }
+ else {
+ confess(blessed($instance)." does not support builder method '".$self->builder."' for attribute '" . $self->name . "'");
+ }
+ }
}
- # 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'";
+ 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);
}
- }
+ $type_constraint->check($val)
+ || confess "Attribute ("
+ . $self->name
+ . ") does not pass the type constraint because: "
+ . $type_constraint->get_message($val);
+ }
- $meta_instance->set_slot_value($instance, $self->name, $val);
- $meta_instance->weaken_slot_value($instance, $self->name)
+ $self->set_initial_value($instance, $val);
+ $meta_instance->weaken_slot_value($instance, $self->name)
if ref $val && $self->is_weak_ref;
}
## Slot management
+# FIXME:
+# this duplicates too much code from
+# Class::MOP::Attribute, we need to
+# refactor these bits eventually.
+# - SL
+sub _set_initial_slot_value {
+ my ($self, $meta_instance, $instance, $value) = @_;
+
+ my $slot_name = $self->name;
+
+ return $meta_instance->set_slot_value($instance, $slot_name, $value)
+ unless $self->has_initializer;
+
+ my ($type_constraint, $can_coerce);
+ if ($self->has_type_constraint) {
+ $type_constraint = $self->type_constraint;
+ $can_coerce = ($self->should_coerce && $type_constraint->has_coercion);
+ }
+
+ my $callback = sub {
+ my $val = shift;
+ if ($type_constraint) {
+ $val = $type_constraint->coerce($val)
+ if $can_coerce;
+ $type_constraint->check($val)
+ || confess "Attribute ("
+ . $slot_name
+ . ") does not pass the type constraint because: "
+ . $type_constraint->get_message($val);
+ }
+ $meta_instance->set_slot_value($instance, $slot_name, $val);
+ };
+
+ my $initializer = $self->initializer;
+
+ # most things will just want to set a value, so make it first arg
+ $instance->$initializer($value, $callback, $self);
+}
+
sub set_value {
my ($self, $instance, $value) = @_;
-
+
my $attr_name = $self->name;
-
+
if ($self->is_required) {
- defined($value)
+ defined($value)
|| confess "Attribute ($attr_name) is required, so cannot be set to undef";
}
-
+
if ($self->has_type_constraint) {
-
+
my $type_constraint = $self->type_constraint;
-
+
if ($self->should_coerce) {
- $value = $type_constraint->coerce($value);
- }
- defined($type_constraint->_compiled_type_constraint->($value))
- || confess "Attribute ($attr_name) does not pass the type constraint ("
- . $type_constraint->name . ") with " . (defined($value) ? ("'" . $value . "'") : "undef")
- if defined($value);
+ $value = $type_constraint->coerce($value);
+ }
+ $type_constraint->_compiled_type_constraint->($value)
+ || confess "Attribute ("
+ . $self->name
+ . ") does not pass the type constraint because "
+ . $type_constraint->get_message($value);
}
-
+
my $meta_instance = Class::MOP::Class->initialize(blessed($instance))
->get_meta_instance;
-
- $meta_instance->set_slot_value($instance, $attr_name, $value);
-
+
+ $meta_instance->set_slot_value($instance, $attr_name, $value);
+
if (ref $value && $self->is_weak_ref) {
- $meta_instance->weaken_slot_value($instance, $attr_name);
+ $meta_instance->weaken_slot_value($instance, $attr_name);
}
-
+
if ($self->has_trigger) {
$self->trigger->($instance, $value, $self);
}
sub get_value {
my ($self, $instance) = @_;
-
+
if ($self->is_lazy) {
- unless ($self->has_value($instance)) {
- if ($self->has_default) {
- my $default = $self->default($instance);
- $self->set_value($instance, $default);
- }
- else {
- $self->set_value($instance, undef);
- }
- }
+ unless ($self->has_value($instance)) {
+ if ($self->has_default) {
+ my $default = $self->default($instance);
+ $self->set_initial_value($instance, $default);
+ }
+ if ( $self->has_builder ){
+ if (my $builder = $instance->can($self->builder)){
+ $self->set_initial_value($instance, $instance->$builder);
+ }
+ else {
+ confess(blessed($instance)
+ . " does not support builder method '"
+ . $self->builder
+ . "' for attribute '"
+ . $self->name
+ . "'");
+ }
+ }
+ else {
+ $self->set_initial_value($instance, undef);
+ }
+ }
}
-
+
if ($self->should_auto_deref) {
-
+
my $type_constraint = $self->type_constraint;
if ($type_constraint->is_a_type_of('ArrayRef')) {
my $rv = $self->SUPER::get_value($instance);
return unless defined $rv;
return wantarray ? @{ $rv } : $rv;
- }
+ }
elsif ($type_constraint->is_a_type_of('HashRef')) {
my $rv = $self->SUPER::get_value($instance);
return unless defined $rv;
return wantarray ? %{ $rv } : $rv;
- }
+ }
else {
confess "Can not auto de-reference the type constraint '" . $type_constraint->name . "'";
}
-
+
}
else {
-
+
return $self->SUPER::get_value($instance);
- }
+ }
}
-## installing accessors
+## installing accessors
sub accessor_metaclass { 'Moose::Meta::Method::Accessor' }
sub install_accessors {
my $self = shift;
- $self->SUPER::install_accessors(@_);
-
+ $self->SUPER::install_accessors(@_);
+
if ($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
+ # 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';
-
+
+ # find the accessor method for this attribute
+ my $accessor = $self->get_read_method_ref;
+ # then unpack it if we need too ...
+ $accessor = $accessor->body if blessed $accessor;
+
# install the delegation ...
my $associated_class = $self->associated_class;
foreach my $handle (keys %handles) {
my $method_to_call = $handles{$handle};
-
+ my $class_name = $associated_class->name;
+ my $name = "${class_name}::${handle}";
+
(!$associated_class->has_method($handle))
|| confess "You cannot overwrite a locally defined method ($handle) with a delegation";
-
+
# NOTE:
# handles is not allowed to delegate
- # any of these methods, as they will
- # override the ones in your class, which
+ # any of these methods, as they will
+ # override the ones in your class, which
# is almost certainly not what you want.
- next if $handle =~ /^BUILD|DEMOLISH$/ || Moose::Object->can($handle);
-
+
+ # FIXME warn when $handle was explicitly specified, but not if the source is a regex or something
+ #cluck("Not delegating method '$handle' because it is a core method") and
+ next if $class_name->isa("Moose::Object") and $handle =~ /^BUILD|DEMOLISH$/ || Moose::Object->can($handle);
+
if ((reftype($method_to_call) || '') eq 'CODE') {
- $associated_class->add_method($handle => $method_to_call);
+ $associated_class->add_method($handle => subname $name, $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(@_);
+ # NOTE:
+ # we used to do a goto here, but the
+ # goto didn't handle failure correctly
+ # (it just returned nothing), so I took
+ # that out. However, the more I thought
+ # about it, the less I liked it doing
+ # the goto, and I prefered the act of
+ # delegation being actually represented
+ # in the stack trace.
+ # - SL
+ $associated_class->add_method($handle => subname $name, sub {
+ my $proxy = (shift)->$accessor();
+ (defined $proxy)
+ || confess "Cannot delegate $handle to $method_to_call because " .
+ "the value of " . $self->name . " is not defined";
+ $proxy->$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);
+ if (my $handle_type = ref($handles)) {
+ if ($handle_type eq 'HASH') {
+ return %{$handles};
+ }
+ elsif ($handle_type eq 'ARRAY') {
+ return map { $_ => $_ } @{$handles};
+ }
+ elsif ($handle_type eq 'Regexp') {
+ ($self->has_type_constraint)
+ || confess "Cannot delegate methods based on a RegExpr without a type constraint (isa)";
+ return map { ($_ => $_) }
+ grep { /$handles/ } $self->_get_delegate_method_list;
+ }
+ elsif ($handle_type eq 'CODE') {
+ return $handles->($self, $self->_find_delegate_metaclass);
+ }
+ else {
+ confess "Unable to canonicalize the 'handles' option with $handles";
+ }
}
else {
- confess "Unable to canonicalize the 'handles' option with $handles";
+ my $role_meta = eval { $handles->meta };
+ if ($@) {
+ confess "Unable to canonicalize the 'handles' option with $handles because : $@";
+ }
+
+ (blessed $role_meta && $role_meta->isa('Moose::Meta::Role'))
+ || confess "Unable to canonicalize the 'handles' option with $handles because ->meta is not a Moose::Meta::Role";
+
+ return map { $_ => $_ } (
+ $role_meta->get_method_list,
+ $role_meta->get_required_method_list
+ );
}
}
sub _find_delegate_metaclass {
my $self = shift;
if (my $class = $self->_isa_metadata) {
- # if the class does have
+ # if the class does have
# a meta method, use it
return $class->meta if $class->can('meta');
- # otherwise we might be
+ # otherwise we might be
# dealing with a non-Moose
- # class, and need to make
+ # class, and need to make
# our own metaclass
return Moose::Meta::Class->initialize($class);
}
elsif (my $role = $self->_does_metadata) {
- # our role will always have
+ # our role will always have
# a meta method
return $role->meta;
}
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' }
+ grep { $_->{class} ne 'Moose::Object' && $_->{name} ne 'meta' }
$meta->compute_all_applicable_methods;
}
elsif ($meta->isa('Moose::Meta::Role')) {
- return $meta->get_method_list;
+ return $meta->get_method_list;
}
else {
confess "Unable to recognize the delegate metaclass '$meta'";
=head1 DESCRIPTION
-This is a subclass of L<Class::MOP::Attribute> with Moose specific
-extensions.
+This is a subclass of L<Class::MOP::Attribute> 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
+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.
=head1 METHODS
=head2 Overridden methods
-These methods override methods in L<Class::MOP::Attribute> and add
-Moose specific features. You can safely assume though that they
+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.
=over 4
=item B<new>
+=item B<does>
+
=item B<initialize_instance_slot>
=item B<install_accessors>
=item B<set_value>
+ eval { $point->meta->get_attribute('x')->set_value($point, 'fourty-two') };
+ if($@) {
+ print "Oops: $@\n";
+ }
+
+I<Attribute (x) does not pass the type constraint (Int) with 'fourty-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
+value fails to pass, the set operation dies with a L<Carp/confess>.
+
+Any coercion to convert values is done before checking the type constraint.
+
+To check a value against a type constraint before setting it, fetch the
+attribute instance using L<Class::MOP::Class/find_attribute_by_name>,
+fetch the type_constraint from the attribute using L<Moose::Meta::Attribute/type_constraint>
+and call L<Moose::Meta::TypeConstraint/check>. See L<Moose::Cookbook::RecipeX>
+for an example.
+
=back
=head2 Additional Moose features
-Moose attributes support type-constraint checking, weak reference
-creation and type coercion.
+Moose attributes support type-constraint checking, weak reference
+creation and type coercion.
=over 4
+=item B<interpolate_class_and_new>
+
+=item B<interpolate_class>
+
+When called as a class method causes interpretation of 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
+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<has_type_constraint>
=item B<type_constraint>
-A read-only accessor for this meta-attribute's type constraint. For
-more information on what you can do with this, see the documentation
+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<has_handles>
Returns true if this meta-attribute should be initialized lazily.
-NOTE: lazy attributes, B<must> have a C<default> field set.
+NOTE: lazy attributes, B<must> have a C<default> or C<builder> field set.
+
+=item B<is_lazy_build>
+
+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.
+
+ #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});
+
+ #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});
+
+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.
+
+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<should_coerce>
=item B<should_auto_deref>
-Returns true if this meta-attribute should perform automatic
-auto-dereferencing.
+Returns true if this meta-attribute should perform automatic
+auto-dereferencing.
-NOTE: This can only be done for attributes whose type constraint is
+NOTE: This can only be done for attributes whose type constraint is
either I<ArrayRef> or I<HashRef>.
=item B<has_trigger>
=item B<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>
+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.
=item B<documentation>
-This is a string which contains the documentation for this attribute.
+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 true if this meta-attribute has any documentation.
+=item B<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>.
+
+=item B<has_applied_traits>
+
+Returns true if this meta-attribute has any traits applied.
+
=back
=head1 BUGS
-All complex software has bugs lurking in it, and this module is no
+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 COPYRIGHT AND LICENSE
-Copyright 2006, 2007 by Infinity Interactive, Inc.
+Copyright 2006-2008 by Infinity Interactive, Inc.
L<http://www.iinteractive.com>
This library is free software; you can redistribute it and/or modify
-it under the same terms as Perl itself.
+it under the same terms as Perl itself.
=cut
projects / gitmo/Moose.git / blobdiff