use Carp 'confess';
use overload ();
-our $VERSION = '0.12';
+our $VERSION = '0.13';
our $AUTHORITY = 'cpan:STEVAN';
use Moose::Meta::Method::Accessor;
# these are actual options for the attrs
__PACKAGE__->meta->add_attribute('required' => (reader => 'is_required' ));
__PACKAGE__->meta->add_attribute('lazy' => (reader => 'is_lazy' ));
+__PACKAGE__->meta->add_attribute('lazy_build' => (reader => 'is_lazy_build' ));
__PACKAGE__->meta->add_attribute('coerce' => (reader => 'should_coerce' ));
__PACKAGE__->meta->add_attribute('weak_ref' => (reader => 'is_weak_ref' ));
__PACKAGE__->meta->add_attribute('auto_deref' => (reader => 'should_auto_deref'));
));
sub new {
- my ($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 clone_and_inherit_options {
delete $options{$legal_option};
}
}
-
+
# handles can only be added, not changed
if ($options{handles}) {
confess "You can only add the 'handles' option, you cannot change it"
$actual_options{handles} = $options{handles};
delete $options{handles};
}
-
- # isa can be changed, but only if the
- # new type is a subtype
+
+ # isa can be changed, but only if the
+ # new type is a subtype
if ($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 {
+ $type_constraint = Moose::Util::TypeConstraints::find_type_constraint($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)
+ (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 {
- $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_type_constraint(
- $options->{isa} => {
- parent => Moose::Util::TypeConstraints::find_type_constraint('Object'),
- constraint => sub { $_[0]->isa($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->{isa};
- }
- else {
- $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_type_constraint(
- $options->{does} => {
- parent => Moose::Util::TypeConstraints::find_type_constraint('Role'),
- constraint => sub { $_[0]->does($options->{does}) }
- }
- );
- }
- }
-
- if (exists $options->{coerce} && $options->{coerce}) {
- (exists $options->{type_constraint})
- || confess "You cannot have coercion without specifying a type constraint";
+
+ if (exists $options->{is}) {
+ if ($options->{is} eq 'ro') {
+ $options->{reader} ||= $name;
+ (!exists $options->{trigger})
+ || confess "Cannot have a trigger on a read-only attribute";
+ }
+ elsif ($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 {
+ $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_type_constraint(
+ $options->{isa} => {
+ parent => Moose::Util::TypeConstraints::find_type_constraint('Object'),
+ constraint => sub { $_[0]->isa($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->{isa};
+ }
+ else {
+ $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_type_constraint(
+ $options->{does} => {
+ parent => Moose::Util::TypeConstraints::find_type_constraint('Role'),
+ constraint => sub { $_[0]->does($options->{does}) }
+ }
+ );
+ }
+ }
+
+ 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') ||
+ 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";
- }
+ || confess "You cannot auto-dereference anything other than a ArrayRef or HashRef";
+ }
+
+ if (exists $options->{lazy_build} && $options->{lazy_build} == 1) {
+ confess("You can not use lazy_build and default for the same attribute")
+ if exists $options->{default};
+ $options->{lazy} = 1;
+ $options->{required} = 1;
+ if($name =~ /^_/){
+ $options->{builder} ||= "_build${name}";
+ $options->{clearer} ||= "_clear${name}";
+ $options->{predicate} ||= "_has${name}";
+ } else {
+ $options->{builder} ||= "build_${name}";
+ $options->{clearer} ||= "clear_${name}";
+ $options->{predicate} ||= "has_${name}";
+ }
+ }
+
+ if (exists $options->{lazy} && $options->{lazy}) {
+ (exists $options->{default} || exists $options->{builder} )
+ || confess "You cannot have lazy attribute without specifying a default value for it";
+ }
+
}
sub initialize_instance_slot {
my $init_arg = $self->init_arg();
# try to fetch the init arg from the %params ...
- my $val;
+ my $val;
if (exists $params->{$init_arg}) {
$val = $params->{$init_arg};
-
+
if (!defined $val && $self->is_required) {
- confess "Attribute (" . $self->name . ") is required and cannot be undef";
+ confess "Attribute (" . $self->name . ") is required and cannot be undef";
}
}
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
+ # 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 || $self->has_default) {
- if ($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 (" .
+ $val = $self->default($instance);
+ } elsif (!defined $val && $self->has_builder) {
+ my $builder = $self->builder;
+ confess(blessed($instance)." does not support builder method '$builder' for attribute '" . $self->name . "'")
+ unless $instance->can($builder);
+ $val = $instance->$builder;
+ }
+
+ if (defined $val || $self->has_default) {
+ if ($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 '" .
- (defined $val
- ? (blessed($val) && overload::Overloaded($val)
- ? overload::StrVal($val)
- : $val)
- : 'undef') .
- "'";
+ ") with '" .
+ (defined $val
+ ? (blessed($val) && overload::Overloaded($val)
+ ? overload::StrVal($val)
+ : $val)
+ : 'undef') .
+ "'";
+ }
}
- }
$meta_instance->set_slot_value($instance, $self->name, $val);
- $meta_instance->weaken_slot_value($instance, $self->name)
+ $meta_instance->weaken_slot_value($instance, $self->name)
if ref $val && $self->is_weak_ref;
}
sub set_value {
my ($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);
+ $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)
- ? ("'" .
- (blessed($value) && overload::Overloaded($value)
- ? overload::StrVal($value)
- : $value)
- . "'")
+ || confess "Attribute ($attr_name) does not pass the type constraint ("
+ . $type_constraint->name
+ . ") with "
+ . (defined($value)
+ ? ("'" .
+ (blessed($value) && overload::Overloaded($value)
+ ? overload::StrVal($value)
+ : $value)
+ . "'")
: "undef")
if defined($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);
+ $self->set_value($instance, $default);
+ }
+ if ( $self->has_builder ){
+ my $builder = $self->builder;
+ confess(blessed($instance)." does not support builder method '$builder' for attribute '" . $self->name . "'")
+ unless $instance->can($builder);
+ $self->set_value($instance, $instance->$builder);
+ } else {
+ $self->set_value($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';
-
+
# 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";
-
+
# 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($handle);
-
+
if ((reftype($method_to_call) || '') eq 'CODE') {
- $associated_class->add_method($handle => $method_to_call);
+ $associated_class->add_method($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
+ # we should check for lack of
+ # a callable return value from
+ # the accessor here
my $proxy = (shift)->$accessor_name();
@_ = ($proxy, @_);
goto &{ $proxy->can($method_to_call)};
}
}
}
-
+
return;
}
elsif ($handle_type eq 'Regexp') {
($self->has_type_constraint)
|| confess "Cannot delegate methods based on a RegExpr without a type constraint (isa)";
- return map { ($_ => $_) }
+ return map { ($_ => $_) }
grep { /$handles/ } $self->_get_delegate_method_list;
}
elsif ($handle_type eq 'CODE') {
else {
my $role_meta = eval { $handles->meta };
if ($@) {
- confess "Unable to canonicalize the 'handles' option with $handles because : $@";
+ 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_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
=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<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, builder => '_build_foo', predicate => '_has_foo', clearer => '_clear_foo');
+ # or
+ has '_foo' => (lazy => 1, required => 1, builder => '_build_foo', default => sub{shift->_build_foo}, clearer => '_clear_foo');
+
+ #If your attribute name does not start with an underscore:
+ has 'foo' => (lazy => 1, required => 1, builder => 'build_foo', predicate => 'has_foo', clearer => 'clear_foo');
+ # or
+ has '_foo' => (lazy => 1, required => 1, builder => '_build_foo', default => sub{shift->build_foo}, clearer => '_clear_foo');
+
+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.
=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.
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