Doc for some of the new meta methods

[gitmo/Mouse.git] / lib / Mouse / Meta / Attribute.pm

diff --git a/lib/Mouse/Meta/Attribute.pm b/lib/Mouse/Meta/Attribute.pm
index dad65a8..af9e737 100644 (file)
--- a/lib/Mouse/Meta/Attribute.pm
+++ b/lib/Mouse/Meta/Attribute.pm
@@ -10,10 +10,30 @@ sub new {
     my $class = shift;
     my %args  = @_;
 
-    $args{init_arg} = $args{name}
+    my $name = $args{name};
+
+    $args{init_arg} = $name
         unless exists $args{init_arg};
+
     $args{is} ||= '';
 
+    if ($args{lazy_build}) {
+        confess("You can not use lazy_build and default for the same attribute $name")
+            if exists $args{default};
+        $args{lazy}      = 1;
+        $args{required}  = 1;
+        $args{builder}   = "_build_${name}"
+            if !exists($args{builder});
+        if ($name =~ /^_/) {
+            $args{clearer}   = "_clear${name}" if !exists($args{clearer});
+            $args{predicate} = "_has${name}" if !exists($args{predicate});
+        }
+        else {
+            $args{clearer}   = "clear_${name}" if !exists($args{clearer});
+            $args{predicate} = "has_${name}" if !exists($args{predicate});
+        }
+    }
+
     bless \%args, $class;
 }
 
@@ -23,6 +43,7 @@ sub _is_metadata      { $_[0]->{is}              }
 sub is_required       { $_[0]->{required}        }
 sub default           { $_[0]->{default}         }
 sub is_lazy           { $_[0]->{lazy}            }
+sub is_lazy_build     { $_[0]->{lazy_build}      }
 sub predicate         { $_[0]->{predicate}       }
 sub clearer           { $_[0]->{clearer}         }
 sub handles           { $_[0]->{handles}         }
@@ -41,6 +62,11 @@ sub has_type_constraint { exists $_[0]->{type_constraint} }
 sub has_trigger         { exists $_[0]->{trigger}         }
 sub has_builder         { exists $_[0]->{builder}         }
 
+sub _create_args {
+    $_[0]->{_create_args} = $_[1] if @_ > 1;
+    $_[0]->{_create_args}
+}
+
 sub generate_accessor {
     my $attribute = shift;
 
@@ -155,25 +181,17 @@ sub generate_handles {
 sub create {
     my ($self, $class, $name, %args) = @_;
 
-    confess "You cannot have lazy attribute ($name) without specifying a default value for it"
-        if $args{lazy} && !exists($args{default}) && !exists($args{builder});
+    $args{name} = $name;
+    $args{class} = $class;
 
-    confess "References are not allowed as default values, you must wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])"
-        if ref($args{default})
-        && ref($args{default}) ne 'CODE';
-
-    confess "You cannot auto-dereference without specifying a type constraint on attribute $name"
-        if $args{auto_deref} && !exists($args{isa});
-
-    confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute $name"
-        if $args{auto_deref}
-        && $args{isa} ne 'ArrayRef'
-        && $args{isa} ne 'HashRef';
+    $self->validate_args($name, %args);
 
     $args{type_constraint} = delete $args{isa}
         if exists $args{isa};
 
-    my $attribute = $self->new(%args, name => $name, class => $class);
+    my $attribute = $self->new(%args);
+    $attribute->_create_args(\%args);
+
     my $meta = $class->meta;
 
     $meta->add_attribute($attribute);
@@ -206,6 +224,29 @@ sub create {
     return $attribute;
 }
 
+sub validate_args {
+    my $self = shift;
+    my $name = shift;
+    my %args = @_;
+
+    confess "You cannot have lazy attribute ($name) without specifying a default value for it"
+        if $args{lazy} && !exists($args{default}) && !exists($args{builder});
+
+    confess "References are not allowed as default values, you must wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])"
+        if ref($args{default})
+        && ref($args{default}) ne 'CODE';
+
+    confess "You cannot auto-dereference without specifying a type constraint on attribute $name"
+        if $args{auto_deref} && !exists($args{isa});
+
+    confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute $name"
+        if $args{auto_deref}
+        && $args{isa} ne 'ArrayRef'
+        && $args{isa} ne 'HashRef';
+
+    return 1;
+}
+
 sub find_type_constraint {
     my $self = shift;
     my $type = $self->type_constraint;
@@ -248,6 +289,29 @@ sub _canonicalize_handles {
     }
 }
 
+sub clone_parent {
+    my $self  = shift;
+    my $class = shift;
+    my $name  = shift;
+    my %args  = ($self->get_parent_args($class, $name), @_);
+
+    $self->create($class, $name, %args);
+}
+
+sub get_parent_args {
+    my $self  = shift;
+    my $class = shift;
+    my $name  = shift;
+
+    for my $super ($class->meta->linearized_isa) {
+        my $super_attr = $super->can("meta") && $super->meta->get_attribute($name)
+            or next;
+        return %{ $super_attr->_create_args };
+    }
+
+    confess "Could not find an attribute by the name of '$name' to inherit from";
+}
+
 1;
 
 __END__
@@ -307,6 +371,8 @@ installed. Some error checking is done.
 
 =head2 has_builder -> Bool
 
+=head2 is_lazy_build => Bool
+
 =head2 should_auto_deref -> Bool
 
 Informational methods.
@@ -337,5 +403,15 @@ this attribute's type constraint;
 Checks that the given value passes this attribute's type constraint. Returns 1
 on success, otherwise C<confess>es.
 
+=head2 clone_parent OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute
+
+Creates a new attribute in OwnerClass, inheriting options from parent classes.
+Accessors and helper methods are installed. Some error checking is done.
+
+=head2 get_parent_args OwnerClass, AttributeName -> Hash
+
+Returns the options that the parent class of C<OwnerClass> used for attribute
+C<AttributeName>.
+
 =cut