use Class::MOP::Method::Accessor;
use Carp 'confess';
-use Scalar::Util 'blessed', 'reftype', 'weaken';
+use Scalar::Util 'blessed', 'weaken';
-our $VERSION = '0.22';
+our $VERSION = '0.76';
+$VERSION = eval $VERSION;
our $AUTHORITY = 'cpan:STEVAN';
use base 'Class::MOP::Object';
-sub meta {
- require Class::MOP::Class;
- Class::MOP::Class->initialize(blessed($_[0]) || $_[0]);
-}
-
# NOTE: (meta-circularity)
# This method will be replaced in the
# boostrap section of Class::MOP, by
# meta-objects.
# - Ain't meta-circularity grand? :)
sub new {
- my $class = shift;
- my $name = shift;
- my %options = @_;
+ my ( $class, @args ) = @_;
+
+ unshift @args, "name" if @args % 2 == 1;
+ my %options = @args;
+
+ my $name = $options{name};
(defined $name && $name)
|| confess "You must provide a name for the attribute";
} else {
(is_default_a_coderef(\%options))
|| confess("References are not allowed as default values, you must ".
- "wrap then in a CODE reference (ex: sub { [] } and not [])")
+ "wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])")
if exists $options{default} && ref $options{default};
}
if( $options{required} and not( defined($options{builder}) || defined($options{init_arg}) || exists $options{default} ) ) {
confess("A required attribute must have either 'init_arg', 'builder', or 'default'");
}
+
+ $class->_new(\%options);
+}
+
+sub _new {
+ my $class = shift;
+ my $options = @_ == 1 ? $_[0] : {@_};
+
bless {
- '$!name' => $name,
- '$!accessor' => $options{accessor},
- '$!reader' => $options{reader},
- # NOTE:
- # protect this from silliness
- init_arg => '!............( DO NOT DO THIS )............!',
- '$!writer' => $options{writer},
- '$!predicate' => $options{predicate},
- '$!clearer' => $options{clearer},
- '$!builder' => $options{builder},
- '$!init_arg' => $options{init_arg},
- '$!default' => $options{default},
+ 'name' => $options->{name},
+ 'accessor' => $options->{accessor},
+ 'reader' => $options->{reader},
+ 'writer' => $options->{writer},
+ 'predicate' => $options->{predicate},
+ 'clearer' => $options->{clearer},
+ 'builder' => $options->{builder},
+ 'init_arg' => $options->{init_arg},
+ 'default' => $options->{default},
+ 'initializer' => $options->{initializer},
+ 'definition_context' => $options->{definition_context},
# keep a weakened link to the
# class we are associated with
- '$!associated_class' => undef,
+ 'associated_class' => undef,
# and a list of the methods
# associated with this attr
- '@!associated_methods' => [],
- } => $class;
+ 'associated_methods' => [],
+ }, $class;
}
# NOTE:
my %options = @_;
(blessed($self))
|| confess "Can only clone an instance";
- return bless { %{$self}, %options } => blessed($self);
+ return bless { %{$self}, %options } => ref($self);
}
sub initialize_instance_slot {
my ($self, $meta_instance, $instance, $params) = @_;
- my $init_arg = $self->{'$!init_arg'};
+ my $init_arg = $self->{'init_arg'};
+
# try to fetch the init arg from the %params ...
# if nothing was in the %params, we can use the
# attribute's default value (if it has one)
if(defined $init_arg and exists $params->{$init_arg}){
- $meta_instance->set_slot_value($instance, $self->name, $params->{$init_arg});
+ $self->_set_initial_slot_value(
+ $meta_instance,
+ $instance,
+ $params->{$init_arg},
+ );
}
- elsif (defined $self->{'$!default'}) {
- $meta_instance->set_slot_value($instance, $self->name, $self->default($instance));
+ elsif (defined $self->{'default'}) {
+ $self->_set_initial_slot_value(
+ $meta_instance,
+ $instance,
+ $self->default($instance),
+ );
}
- elsif (defined( my $builder = $self->{'$!builder'})) {
+ elsif (defined( my $builder = $self->{'builder'})) {
if ($builder = $instance->can($builder)) {
- $meta_instance->set_slot_value($instance, $self->name, $instance->$builder);
+ $self->_set_initial_slot_value(
+ $meta_instance,
+ $instance,
+ $instance->$builder,
+ );
}
else {
- confess(blessed($instance)." does not support builder method '". $self->{'$!builder'} ."' for attribute '" . $self->name . "'");
+ confess(ref($instance)." does not support builder method '". $self->{'builder'} ."' for attribute '" . $self->name . "'");
}
}
}
-# NOTE:
-# the next bunch of methods will get bootstrapped
-# away in the Class::MOP bootstrapping section
+sub _set_initial_slot_value {
+ my ($self, $meta_instance, $instance, $value) = @_;
+
+ my $slot_name = $self->name;
-sub name { $_[0]->{'$!name'} }
+ return $meta_instance->set_slot_value($instance, $slot_name, $value)
+ unless $self->has_initializer;
-sub associated_class { $_[0]->{'$!associated_class'} }
-sub associated_methods { $_[0]->{'@!associated_methods'} }
+ my $callback = sub {
+ $meta_instance->set_slot_value($instance, $slot_name, $_[0]);
+ };
+
+ my $initializer = $self->initializer;
+
+ # most things will just want to set a value, so make it first arg
+ $instance->$initializer($value, $callback, $self);
+}
-sub has_accessor { defined($_[0]->{'$!accessor'}) ? 1 : 0 }
-sub has_reader { defined($_[0]->{'$!reader'}) ? 1 : 0 }
-sub has_writer { defined($_[0]->{'$!writer'}) ? 1 : 0 }
-sub has_predicate { defined($_[0]->{'$!predicate'}) ? 1 : 0 }
-sub has_clearer { defined($_[0]->{'$!clearer'}) ? 1 : 0 }
-sub has_builder { defined($_[0]->{'$!builder'}) ? 1 : 0 }
-sub has_init_arg { defined($_[0]->{'$!init_arg'}) ? 1 : 0 }
-sub has_default { defined($_[0]->{'$!default'}) ? 1 : 0 }
+# NOTE:
+# the next bunch of methods will get bootstrapped
+# away in the Class::MOP bootstrapping section
-sub accessor { $_[0]->{'$!accessor'} }
-sub reader { $_[0]->{'$!reader'} }
-sub writer { $_[0]->{'$!writer'} }
-sub predicate { $_[0]->{'$!predicate'} }
-sub clearer { $_[0]->{'$!clearer'} }
-sub builder { $_[0]->{'$!builder'} }
-sub init_arg { $_[0]->{'$!init_arg'} }
+sub name { $_[0]->{'name'} }
+
+sub associated_class { $_[0]->{'associated_class'} }
+sub associated_methods { $_[0]->{'associated_methods'} }
+
+sub has_accessor { defined($_[0]->{'accessor'}) }
+sub has_reader { defined($_[0]->{'reader'}) }
+sub has_writer { defined($_[0]->{'writer'}) }
+sub has_predicate { defined($_[0]->{'predicate'}) }
+sub has_clearer { defined($_[0]->{'clearer'}) }
+sub has_builder { defined($_[0]->{'builder'}) }
+sub has_init_arg { defined($_[0]->{'init_arg'}) }
+sub has_default { defined($_[0]->{'default'}) }
+sub has_initializer { defined($_[0]->{'initializer'}) }
+
+sub accessor { $_[0]->{'accessor'} }
+sub reader { $_[0]->{'reader'} }
+sub writer { $_[0]->{'writer'} }
+sub predicate { $_[0]->{'predicate'} }
+sub clearer { $_[0]->{'clearer'} }
+sub builder { $_[0]->{'builder'} }
+sub init_arg { $_[0]->{'init_arg'} }
+sub initializer { $_[0]->{'initializer'} }
+sub definition_context { $_[0]->{'definition_context'} }
# end bootstrapped away method section.
# (all methods below here are kept intact)
+sub has_read_method { $_[0]->has_reader || $_[0]->has_accessor }
+sub has_write_method { $_[0]->has_writer || $_[0]->has_accessor }
+
sub get_read_method {
my $self = shift;
my $reader = $self->reader || $self->accessor;
return $self->associated_class->get_method($reader);
}
else {
- return sub { $self->get_value(@_) };
+ my $code = sub { $self->get_value(@_) };
+ if (my $class = $self->associated_class) {
+ return $class->method_metaclass->wrap(
+ $code,
+ package_name => $class->name,
+ name => '__ANON__'
+ );
+ }
+ else {
+ return $code;
+ }
}
}
return $self->associated_class->get_method($writer);
}
else {
- return sub { $self->set_value(@_) };
+ my $code = sub { $self->set_value(@_) };
+ if (my $class = $self->associated_class) {
+ return $class->method_metaclass->wrap(
+ $code,
+ package_name => $class->name,
+ name => '__ANON__'
+ );
+ }
+ else {
+ return $code;
+ }
}
}
sub is_default_a_coderef {
- ('CODE' eq (reftype($_[0]->{'$!default'} || $_[0]->{default}) || ''))
+ ('CODE' eq ref($_[0]->{'default'}))
}
sub default {
# we pass in the instance and default
# can return a value based on that
# instance. Somewhat crude, but works.
- return $self->{'$!default'}->($instance);
+ return $self->{'default'}->($instance);
}
- $self->{'$!default'};
+ $self->{'default'};
}
# slots
my ($self, $class) = @_;
(blessed($class) && $class->isa('Class::MOP::Class'))
|| confess "You must pass a Class::MOP::Class instance (or a subclass)";
- weaken($self->{'$!associated_class'} = $class);
+ weaken($self->{'associated_class'} = $class);
}
sub detach_from_class {
my $self = shift;
- $self->{'$!associated_class'} = undef;
+ $self->{'associated_class'} = undef;
}
# method association
sub associate_method {
my ($self, $method) = @_;
- push @{$self->{'@!associated_methods'}} => $method;
+ push @{$self->{'associated_methods'}} => $method;
}
## Slot management
+sub set_initial_value {
+ my ($self, $instance, $value) = @_;
+ $self->_set_initial_slot_value(
+ Class::MOP::Class->initialize(ref($instance))->get_meta_instance,
+ $instance,
+ $value
+ );
+}
+
sub set_value {
my ($self, $instance, $value) = @_;
- Class::MOP::Class->initialize(blessed($instance))
+ Class::MOP::Class->initialize(ref($instance))
->get_meta_instance
->set_slot_value($instance, $self->name, $value);
}
sub get_value {
my ($self, $instance) = @_;
- Class::MOP::Class->initialize(blessed($instance))
+ Class::MOP::Class->initialize(ref($instance))
->get_meta_instance
->get_slot_value($instance, $self->name);
}
sub has_value {
my ($self, $instance) = @_;
- Class::MOP::Class->initialize(blessed($instance))
+ Class::MOP::Class->initialize(ref($instance))
->get_meta_instance
->is_slot_initialized($instance, $self->name);
}
sub clear_value {
my ($self, $instance) = @_;
- Class::MOP::Class->initialize(blessed($instance))
+ Class::MOP::Class->initialize(ref($instance))
->get_meta_instance
->deinitialize_slot($instance, $self->name);
}
sub process_accessors {
my ($self, $type, $accessor, $generate_as_inline_methods) = @_;
- if (reftype($accessor)) {
- (reftype($accessor) eq 'HASH')
+
+ my $method_ctx;
+
+ if ( my $ctx = $self->definition_context ) {
+ $method_ctx = { %$ctx };
+ }
+
+ if (ref($accessor)) {
+ (ref($accessor) eq 'HASH')
|| confess "bad accessor/reader/writer/predicate/clearer format, must be a HASH ref";
my ($name, $method) = %{$accessor};
- $method = $self->accessor_metaclass->wrap($method);
+ $method = $self->accessor_metaclass->wrap(
+ $method,
+ package_name => $self->associated_class->name,
+ name => $name,
+ definition_context => $method_ctx,
+ );
$self->associate_method($method);
return ($name, $method);
}
my $inline_me = ($generate_as_inline_methods && $self->associated_class->instance_metaclass->is_inlinable);
my $method;
eval {
+ if ( $method_ctx ) {
+ my $desc = "accessor $accessor";
+ if ( $accessor ne $self->name ) {
+ $desc .= " of attribute " . $self->name;
+ }
+
+ $method_ctx->{description} = $desc;
+ }
+
$method = $self->accessor_metaclass->new(
attribute => $self,
is_inline => $inline_me,
accessor_type => $type,
+ package_name => $self->associated_class->name,
+ name => $accessor,
+ definition_context => $method_ctx,
);
};
confess "Could not create the '$type' method for " . $self->name . " because : $@" if $@;
{
my $_remove_accessor = sub {
my ($accessor, $class) = @_;
- if (reftype($accessor) && reftype($accessor) eq 'HASH') {
+ if (ref($accessor) && ref($accessor) eq 'HASH') {
($accessor) = keys %{$accessor};
}
my $method = $class->get_method($accessor);
$class->remove_method($accessor)
- if (blessed($method) && $method->isa('Class::MOP::Method::Accessor'));
+ if (ref($method) && $method->isa('Class::MOP::Method::Accessor'));
};
sub remove_accessors {
=head1 SYNOPSIS
- Class::MOP::Attribute->new('$foo' => (
+ Class::MOP::Attribute->new( foo => (
accessor => 'foo', # dual purpose get/set accessor
predicate => 'has_foo' # predicate check for defined-ness
init_arg => '-foo', # class->new will look for a -foo key
default => 'BAR IS BAZ!' # if no -foo key is provided, use this
));
- Class::MOP::Attribute->new('$.bar' => (
+ Class::MOP::Attribute->new( bar => (
reader => 'bar', # getter
writer => 'set_bar', # setter
predicate => 'has_bar' # predicate check for defined-ness
MyClass->meta->construct_instance(-foo => "Hello There");
In an init_arg is not assigned, it will automatically use the
-value of C<$name>.
+value of C<$name>. If an explicit C<undef> is given for an init_arg,
+an attribute value can't be specified during initialization.
=item I<builder>
And lastly, if the value of your attribute is dependent upon
some other aspect of the instance structure, then you can take
advantage of the fact that when the I<default> value is a CODE
-reference, it is passed the raw (unblessed) instance structure
+reference, it is passed the (as yet unfinished) instance structure
as it's only argument. So you can do things like this:
Class::MOP::Attribute->new('$object_identity' => (
this class to acheive it. However, this is currently left as
an exercise to the reader :).
+=item I<initializer>
+
+This may be a method name (referring to a method on the class with this
+attribute) or a CODE ref. The initializer is used to set the attribute value
+on an instance when the attribute is set during instance initialization. When
+called, it is passed the instance (as the invocant), the value to set, a
+slot-setting CODE ref, and the attribute meta-instance. The slot-setting code
+is provided to make it easy to set the (possibly altered) value on the instance
+without going through several more method calls.
+
+This contrived example shows an initializer that sets the attribute to twice
+the given value.
+
+ Class::MOP::Attribute->new('$doubled' => (
+ initializer => sub {
+ my ($instance, $value, $set) = @_;
+ $set->($value * 2);
+ },
+ ));
+
+As method names can be given as initializers, one can easily make
+attribute initialization use the writer:
+
+ Class::MOP::Attribute->new('$some_attr' => (
+ writer => 'some_attr',
+ initializer => 'some_attr',
+ ));
+
+Your writer will simply need to examine it's C<@_> and determine under
+which context it is being called.
+
=back
The I<accessor>, I<reader>, I<writer>, I<predicate> and I<clearer> keys can
If you really want to get rid of the value, you have to define and
use a I<clearer> (see below).
-
=item I<clearer>
This is the a method that will uninitialize the attr, reverting lazy values
=item B<clone (%options)>
+This will return a clone of the attribute instance, allowing the overriding
+of various attributes through the C<%options> supplied.
+
=item B<initialize_instance_slot ($instance, $params)>
+This method is used internally to initialize the approriate slot for this
+attribute in a given C<$instance>, the C<$params> passed are those that were
+passed to the constructor.
+
=back
=head2 Value management
Set the value without going through the accessor. Note that this may be done to
even attributes with just read only accessors.
+=item B<set_initial_value ($instance, $value)>
+
+This method sets the value without going through the accessor -- but it is only
+called when the instance data is first initialized.
+
=item B<get_value ($instance)>
Return the value without going through the accessor. Note that this may be done
=item B<clearer>
+=item B<initializer>
+
=item B<init_arg>
=item B<is_default_a_coderef>
value of the attribute in the associated class. Suitable for use whether
C<reader> and C<writer> or C<accessor> was specified or not.
-NOTE: If not reader/writer/accessor was specified, this will use the
+NOTE: If no reader/writer/accessor was specified, this will use the
attribute get_value/set_value methods, which can be very inefficient.
+=item B<has_read_method>
+
+=item B<has_write_method>
+
+Return whether a method exists suitable for reading / writing the value
+of the attribute in the associated class. Suitable for use whether
+C<reader> and C<writer> or C<accessor> was used.
+
=back
=head2 Informational predicates
=item B<has_clearer>
+=item B<has_initializer>
+
=item B<has_init_arg>
=item B<has_default>
=item B<associated_methods>
This will return the list of methods which have been associated with
-the C<associate_method> methods.
+the C<associate_method> methods. This is a good way of seeing what
+methods are used to manage a given attribute.
=item B<install_accessors>
It should also be noted that B<Class::MOP> will actually bootstrap
this module by installing a number of attribute meta-objects into
-it's metaclass. This will allow this class to reap all the benifits
+it's metaclass. This will allow this class to reap all the benefits
of the MOP when subclassing it.
=back
projects / gitmo/Class-MOP.git / blobdiff