Special case new to avoid unexpected exceptions on unloaded classes

[gitmo/MooseX-Types.git] / lib / MooseX / Types / TypeDecorator.pm

diff --git a/lib/MooseX/Types/TypeDecorator.pm b/lib/MooseX/Types/TypeDecorator.pm
index fa97bb7..16e4fe0 100644 (file)
--- a/lib/MooseX/Types/TypeDecorator.pm
+++ b/lib/MooseX/Types/TypeDecorator.pm
@@ -112,13 +112,16 @@ sub __type_constraint {
 
 =head2 isa
 
-handle $self->isa since AUTOLOAD can't.
+handle $self->isa since AUTOLOAD can't - this tries both the type constraint,
+and for a class type, the class.
 
 =cut
 
 sub isa {
-  return 1 if $_[1]->isa('Moose::Meta::TypeConstraint');
-  shift->_try_delegate('isa', @_)
+  my $self = shift;
+  return
+    $self->__type_constraint->isa(@_)
+    || $self->_try_delegate('isa', @_);
 }
 
 =head2 can
@@ -154,7 +157,11 @@ sub DESTROY {
 
 =head2 AUTOLOAD
 
-Delegate to the decorator target.
+Delegate to the decorator target, unless this is a class type, in which
+case it will try to delegate to the type object, then if that fails try
+the class. The method 'new' is special cased to only be permitted on
+the class; if there is no class, or it does not provide a new method,
+an exception will be thrown.
 
 =cut
 
@@ -173,24 +180,34 @@ sub _try_delegate {
     my ($self, $method, @args) = @_;
     my $tc = $self->__type_constraint;
     my $class;
-    my $search_tc = $tc;
-    while ($search_tc->is_subtype_of('Object')) {
-        if ($search_tc->isa('Moose::Meta::TypeConstraint::Class')) {
-            $class = $search_tc->class;
-            last;
+    if ($tc->can('is_subtype_of')) { # Union can't
+        my $search_tc = $tc;
+        while (1) {
+            if ($search_tc->isa('Moose::Meta::TypeConstraint::Class')) {
+                $class = $search_tc->class;
+                last;
+            }
+            $search_tc = $search_tc->parent;
+            last unless $search_tc->is_subtype_of('Object');
         }
-        $search_tc = $search_tc->parent;
     }
         
-    my $inv = (
-        $class
-            ? (
-                $method eq 'new' || $class->can($method)
-                    ? $class
-                    : $tc
-              )
-            : $tc
-    );
+    my $inv = do {
+        if ($method eq 'new') {
+            die "new called on type decorator for non-class-type ".$tc->name
+                unless $class;
+            die "new called on class type decorator ".$tc->name."\n"
+                ." for class ${class}\n"
+                ." which does not provide a new method - did you forget to load it?"
+                unless $class->can('new');
+            $class
+        } elsif ($class && !$tc->can($method)) {
+            $class
+        } else {
+            $tc
+        }
+    };
+
     $inv->$method(@args);
 }