mop

[gitmo/Class-MOP.git] / lib / Class / MOP / Attribute.pm

diff --git a/lib/Class/MOP/Attribute.pm b/lib/Class/MOP/Attribute.pm
index 2a47ecc..df0fb3c 100644 (file)
--- a/lib/Class/MOP/Attribute.pm
+++ b/lib/Class/MOP/Attribute.pm
@@ -7,11 +7,11 @@ use warnings;
 use Carp         'confess';
 use Scalar::Util 'blessed', 'reftype', 'weaken';
 
-our $VERSION = '0.02';
+our $VERSION = '0.07';
 
 sub meta { 
     require Class::MOP::Class;
-    Class::MOP::Class->initialize($_[0]) 
+    Class::MOP::Class->initialize(blessed($_[0]) || $_[0]);
 }
 
 # NOTE: (meta-circularity)
@@ -30,9 +30,8 @@ sub new {
         
     (defined $name && $name)
         || confess "You must provide a name for the attribute";
-    (!exists $options{reader} && !exists $options{writer})
-        || confess "You cannot declare an accessor and reader and/or writer functions"
-            if exists $options{accessor};
+    $options{init_arg} = $name 
+        if not exists $options{init_arg};
             
     bless {
         name      => $name,
@@ -48,8 +47,41 @@ sub new {
     } => $class;
 }
 
+# NOTE:
+# this is a primative (and kludgy) clone operation 
+# for now, it will be repleace in the Class::MOP
+# bootstrap with a proper one, however we know 
+# that this one will work fine for now.
+sub clone {
+    my $self    = shift;
+    my %options = @_;
+    (blessed($self))
+        || confess "Can only clone an instance";
+    return bless { %{$self}, %options } => blessed($self);
+}
+
+sub initialize_instance_slot {
+    my ($self, $class, $instance, $params) = @_;
+    my $init_arg = $self->{init_arg};
+    # try to fetch the init arg from the %params ...
+    my $val;        
+    $val = $params->{$init_arg} if exists $params->{$init_arg};
+    # if nothing was in the %params, we can use the 
+    # attribute's default value (if it has one)
+    if (!defined $val && defined $self->{default}) {
+        $val = $self->default($instance); 
+    }            
+    $instance->{$self->name} = $val;    
+}
+
+# NOTE:
+# the next bunch of methods will get bootstrapped 
+# away in the Class::MOP bootstrapping section
+
 sub name { $_[0]->{name} }
 
+sub associated_class { $_[0]->{associated_class} }
+
 sub has_accessor  { defined($_[0]->{accessor})  ? 1 : 0 }
 sub has_reader    { defined($_[0]->{reader})    ? 1 : 0 }
 sub has_writer    { defined($_[0]->{writer})    ? 1 : 0 }
@@ -63,6 +95,9 @@ sub writer    { $_[0]->{writer}    }
 sub predicate { $_[0]->{predicate} }
 sub init_arg  { $_[0]->{init_arg}  }
 
+# end bootstrapped away method section.
+# (all methods below here are kept intact)
+
 sub default { 
     my $self = shift;
     if (reftype($self->{default}) && reftype($self->{default}) eq 'CODE') {
@@ -77,8 +112,6 @@ sub default {
 
 # class association 
 
-sub associated_class { $_[0]->{associated_class} }
-
 sub attach_to_class {
     my ($self, $class) = @_;
     (blessed($class) && $class->isa('Class::MOP::Class'))
@@ -95,36 +128,35 @@ sub detach_from_class {
 
 sub generate_accessor_method {
     my ($self, $attr_name) = @_;
-    eval qq{sub {
-        \$_[0]->{'$attr_name'} = \$_[1] if scalar(\@_) == 2;
-        \$_[0]->{'$attr_name'};
-    }};
+    sub {
+        $_[0]->{$attr_name} = $_[1] if scalar(@_) == 2;
+        $_[0]->{$attr_name};
+    };
 }
 
 sub generate_reader_method {
     my ($self, $attr_name) = @_; 
-    eval qq{sub {
-        \$_[0]->{'$attr_name'};
-    }};   
+    sub { 
+        confess "Cannot assign a value to a read-only accessor" if @_ > 1;
+        $_[0]->{$attr_name}; 
+    };   
 }
 
 sub generate_writer_method {
     my ($self, $attr_name) = @_; 
-    eval qq{sub {
-        \$_[0]->{'$attr_name'} = \$_[1];
-    }};
+    sub { $_[0]->{$attr_name} = $_[1] };
 }
 
 sub generate_predicate_method {
     my ($self, $attr_name) = @_; 
-    eval qq{sub {
-        defined \$_[0]->{'$attr_name'} ? 1 : 0;
-    }};
+    sub { defined $_[0]->{$attr_name} ? 1 : 0 };
 }
 
 sub process_accessors {
     my ($self, $type, $accessor) = @_;
-    if (reftype($accessor) && reftype($accessor) eq 'HASH') {
+    if (reftype($accessor)) {
+        (reftype($accessor) eq 'HASH')
+            || confess "bad accessor/reader/writer/predicate format, must be a HASH ref";
         my ($name, $method) = each %{$accessor};
         return ($name, Class::MOP::Attribute::Accessor->wrap($method));        
     }
@@ -255,6 +287,9 @@ value of C<-foo>, then the following code will Just Work.
 
   MyClass->meta->construct_instance(-foo => "Hello There");
 
+In an init_arg is not assigned, it will automatically use the 
+value of C<$name>.
+
 =item I<default>
 
 The value of this key is the default value which 
@@ -352,6 +387,10 @@ defined, and false (C<0>) otherwise.
 
 =back
 
+=item B<clone (%options)>
+
+=item B<initialize_instance_slot ($instance, $params)>
+
 =back 
 
 =head2 Informational