allow class_type to accept a custom message. sorry about the diffnoise, editor strips...
[gitmo/Moose.git] / lib / Moose / Meta / Attribute.pm
index 9dbc1c2..80c16cd 100644 (file)
@@ -6,9 +6,10 @@ use warnings;
 
 use Scalar::Util 'blessed', 'weaken', 'reftype';
 use Carp         'confess';
+use Sub::Name    'subname';
 use overload     ();
 
-our $VERSION   = '0.15';
+our $VERSION   = '0.22';
 our $AUTHORITY = 'cpan:STEVAN';
 
 use Moose::Meta::Method::Accessor;
@@ -70,6 +71,14 @@ sub clone_and_inherit_options {
         $actual_options{handles} = $options{handles};
         delete $options{handles};
     }
+    
+    # handles can only be added, not changed
+    if ($options{builder}) {
+        confess "You can only add the 'builder' option, you cannot change it"
+            if $self->has_builder;
+        $actual_options{builder} = $options{builder};
+        delete $options{builder};
+    }    
 
     # isa can be changed, but only if the
     # new type is a subtype
@@ -148,13 +157,15 @@ sub _process_options {
     elsif (exists $options->{does}) {
         # allow for anon-subtypes here ...
         if (blessed($options->{does}) && $options->{does}->isa('Moose::Meta::TypeConstraint')) {
-                $options->{type_constraint} = $options->{isa};
+                $options->{type_constraint} = $options->{does};
         }
         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}) }
+                    constraint => sub { 
+                        Moose::Util::does_role($_[0], $options->{does})
+                    }
                 }
             );
         }
@@ -178,23 +189,28 @@ sub _process_options {
     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;
-            $options->{builder}   ||= "_build_${name}";
-        if($name =~ /^_/){
+        $options->{lazy}      = 1;
+        $options->{required}  = 1;
+        $options->{builder} ||= "_build_${name}";
+        if ($name =~ /^_/) {
             $options->{clearer}   ||= "_clear${name}";
             $options->{predicate} ||= "_has${name}";
-        } else {
+        } 
+        else {
             $options->{clearer}   ||= "clear_${name}";
             $options->{predicate} ||= "has_${name}";
         }
     }
 
     if (exists $options->{lazy} && $options->{lazy}) {
-        (exists $options->{default} || exists $options->{builder} )
+        (exists $options->{default} || defined $options->{builder} )
             || confess "You cannot have lazy attribute 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 without a default, builder, or an init_arg";
+    }
+
 }
 
 sub initialize_instance_slot {
@@ -204,9 +220,9 @@ sub initialize_instance_slot {
 
     my $val;
     my $value_is_set;
-    if (exists $params->{$init_arg}) {
+    if ( defined($init_arg) and exists $params->{$init_arg}) {
         $val = $params->{$init_arg};
-        $value_is_set = 1;
+        $value_is_set = 1;    
     }
     else {
         # skip it if it's lazy
@@ -220,11 +236,13 @@ sub initialize_instance_slot {
         if ($self->has_default) {
             $val = $self->default($instance);
             $value_is_set = 1;
-        } elsif ($self->has_builder) {
-            if(my $builder = $instance->can($self->builder)){
+        } 
+        elsif ($self->has_builder) {
+            if (my $builder = $instance->can($self->builder)){
                 $val = $instance->$builder;
                 $value_is_set = 1;
-            } else {
+            } 
+            else {
                 confess(blessed($instance)." does not support builder method '".$self->builder."' for attribute '" . $self->name . "'");
             }
         }
@@ -237,27 +255,59 @@ sub initialize_instance_slot {
         if ($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') .
-                       "'";
+        $type_constraint->check($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);
+    $self->set_initial_value($instance, $val);
     $meta_instance->weaken_slot_value($instance, $self->name)
-      if ref $val && $self->is_weak_ref;
+        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) = @_;
 
@@ -274,19 +324,12 @@ sub set_value {
 
         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)
-                    ? ("'" .
-                        (blessed($value) && overload::Overloaded($value)
-                            ? overload::StrVal($value)
-                            : $value)
-                        . "'")
-                    : "undef")
-          if defined($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))
@@ -310,16 +353,23 @@ sub get_value {
         unless ($self->has_value($instance)) {
             if ($self->has_default) {
                 my $default = $self->default($instance);
-                $self->set_value($instance, $default);
+                $self->set_initial_value($instance, $default);
             }
             if ( $self->has_builder ){
-                if(my $builder = $instance->can($self->builder)){
-                    $self->set_value($instance, $instance->$builder);
-                } else {
-                    confess(blessed($instance)." does not support builder method '".$self->builder."' for attribute '" . $self->name . "'");
+                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 {
-                $self->set_value($instance, undef);
+            } 
+            else {
+                $self->set_initial_value($instance, undef);
             }
         }
     }
@@ -375,6 +425,8 @@ sub install_accessors {
         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";
@@ -384,20 +436,31 @@ sub install_accessors {
             # 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
+                # 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();
-                    @_ = ($proxy, @_);
-                    goto &{ $proxy->can($method_to_call) };
+                    (defined $proxy) 
+                        || confess "Cannot delegate $handle to $method_to_call because " . 
+                                   "the value of " . $self->name . " is not defined";
+                    $proxy->$method_to_call(@_);
                 });
             }
         }
@@ -541,7 +604,7 @@ 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<Moose::Meta::Attribute/find_attribute_by_name>,
+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.
@@ -670,7 +733,7 @@ Yuval Kogman E<lt>nothingmuch@woobling.comE<gt>
 
 =head1 COPYRIGHT AND LICENSE
 
-Copyright 2006, 2007 by Infinity Interactive, Inc.
+Copyright 2006-2008 by Infinity Interactive, Inc.
 
 L<http://www.iinteractive.com>