use strict;
use warnings FATAL => 'all';
-our $VERSION = '1.002005'; # 1.2.5
+our $VERSION = '1.003003';
$VERSION = eval $VERSION;
our %INFO;
our %APPLIED_TO;
our %COMPOSED;
our %COMPOSITE_INFO;
+our @ON_ROLE_CREATE;
# Module state workaround totally stolen from Zefram's Module::Runtime.
BEGIN {
*_WORK_AROUND_BROKEN_MODULE_STATE = "$]" < 5.009 ? sub(){1} : sub(){0};
+ *_MRO_MODULE = "$]" < 5.010 ? sub(){"MRO/Compat.pm"} : sub(){"mro.pm"};
}
sub Role::Tiny::__GUARD__::DESTROY {
my $me = shift;
strict->import;
warnings->import(FATAL => 'all');
- return if $INFO{$target}; # already exported into this package
+ return if $me->is_role($target); # already exported into this package
$INFO{$target}{is_role} = 1;
# get symbol table reference
my $stash = _getstash($target);
@{$INFO{$target}{not_methods}={}}{@not_methods} = @not_methods;
# a role does itself
$APPLIED_TO{$target} = { $target => undef };
+ $_->($target) for @ON_ROLE_CREATE;
}
sub role_application_steps {
- qw(_install_methods _install_modifiers _check_requires _copy_applied_list);
+ qw(_install_methods _check_requires _install_modifiers _copy_applied_list);
}
sub apply_single_role_to_package {
_load_module($role);
die "This is apply_role_to_package" if ref($to);
- die "${role} is not a Role::Tiny" unless $INFO{$role};
+ die "${role} is not a Role::Tiny" unless $me->is_role($role);
foreach my $step ($me->role_application_steps) {
$me->$step($to, $role);
my ($me, $object, @roles) = @_;
die "No roles supplied!" unless @roles;
my $class = ref($object);
- bless($object, $me->create_class_with_roles($class, @roles));
- $object;
+ # on perl < 5.8.9, magic isn't copied to all ref copies. bless the parameter
+ # directly, so at least the variable passed to us will get any magic applied
+ bless($_[1], $me->create_class_with_roles($class, @roles));
+}
+
+my $role_suffix = 'A000';
+sub _composite_name {
+ my ($me, $superclass, @roles) = @_;
+
+ my $new_name = join(
+ '__WITH__', $superclass, my $compose_name = join '__AND__', @roles
+ );
+
+ if (length($new_name) > 252) {
+ $new_name = $COMPOSED{abbrev}{$new_name}
+ ||= substr($new_name, 0, 250 - length $role_suffix).'__'.$role_suffix++;
+ }
+ return wantarray ? ($new_name, $compose_name) : $new_name;
}
sub create_class_with_roles {
}
}
- my $new_name = join(
- '__WITH__', $superclass, my $compose_name = join '__AND__', @roles
- );
+ my ($new_name, $compose_name) = $me->_composite_name($superclass, @roles);
return $new_name if $COMPOSED{class}{$new_name};
foreach my $role (@roles) {
_load_module($role);
- die "${role} is not a Role::Tiny" unless $INFO{$role};
+ die "${role} is not a Role::Tiny" unless $me->is_role($role);
}
- if ($] >= 5.010) {
- require mro;
- } else {
- require MRO::Compat;
- }
+ require(_MRO_MODULE);
- my %conflicts = %{$me->_composite_info_for(@roles)->{conflicts}};
+ my $composite_info = $me->_composite_info_for(@roles);
+ my %conflicts = %{$composite_info->{conflicts}};
if (keys %conflicts) {
- my $fail =
+ my $fail =
join "\n",
map {
"Method name conflict for '$_' between roles "
my @composable = map $me->_composable_package_for($_), reverse @roles;
- *{_getglob("${new_name}::ISA")} = [ @composable, $superclass ];
-
- my @info = map $INFO{$_}, @roles;
+ # some methods may not exist in the role, but get generated by
+ # _composable_package_for (Moose accessors via Moo). filter out anything
+ # provided by the composable packages, excluding the subs we generated to
+ # make modifiers work.
+ my @requires = grep {
+ my $method = $_;
+ !grep $_->can($method) && !$COMPOSED{role}{$_}{modifiers_only}{$method},
+ @composable
+ } @{$composite_info->{requires}};
$me->_check_requires(
- $new_name, $compose_name,
- do { my %h; @h{map @{$_->{requires}||[]}, @info} = (); keys %h }
+ $superclass, $compose_name, \@requires
);
+ *{_getglob("${new_name}::ISA")} = [ @composable, $superclass ];
+
@{$APPLIED_TO{$new_name}||={}}{
map keys %{$APPLIED_TO{$_}}, @roles
} = ();
return $me->apply_role_to_package($to, $roles[0]) if @roles == 1;
my %conflicts = %{$me->_composite_info_for(@roles)->{conflicts}};
- delete $conflicts{$_} for keys %{ $me->_concrete_methods_of($to) };
+ my @have = grep $to->can($_), keys %conflicts;
+ delete @conflicts{@have};
+
if (keys %conflicts) {
- my $fail =
+ my $fail =
join "\n",
map {
"Due to a method name conflict between roles "
die $fail;
}
+ # conflicting methods are supposed to be treated as required by the
+ # composed role. we don't have an actual composed role, but because
+ # we know the target class already provides them, we can instead
+ # pretend that the roles don't do for the duration of application.
+ my @role_methods = map $me->_concrete_methods_of($_), @roles;
+ # separate loops, since local ..., delete ... for ...; creates a scope
+ local @{$_}{@have} for @role_methods;
+ delete @{$_}{@have} for @role_methods;
+
# the if guard here is essential since otherwise we accidentally create
# a $INFO for something that isn't a Role::Tiny (or Moo::Role) because
# autovivification hates us and wants us to die()
if ($INFO{$to}) {
delete $INFO{$to}{methods}; # reset since we're about to add methods
}
- foreach my $step ($me->role_application_steps) {
+
+ # backcompat: allow subclasses to use apply_single_role_to_package
+ # to apply changes. set a local var so ours does nothing.
+ our %BACKCOMPAT_HACK;
+ if($me ne __PACKAGE__
+ and exists $BACKCOMPAT_HACK{$me} ? $BACKCOMPAT_HACK{$me} :
+ $BACKCOMPAT_HACK{$me} =
+ $me->can('role_application_steps')
+ == \&role_application_steps
+ && $me->can('apply_single_role_to_package')
+ != \&apply_single_role_to_package
+ ) {
foreach my $role (@roles) {
- $me->$step($to, $role);
+ $me->apply_single_role_to_package($to, $role);
+ }
+ }
+ else {
+ foreach my $step ($me->role_application_steps) {
+ foreach my $role (@roles) {
+ $me->$step($to, $role);
+ }
}
}
$APPLIED_TO{$to}{join('|',@roles)} = 1;
my $this_methods = $me->_concrete_methods_of($role);
$methods{$_}{$this_methods->{$_}} = $role for keys %$this_methods;
}
+ my %requires;
+ @requires{map @{$INFO{$_}{requires}||[]}, @roles} = ();
+ delete $requires{$_} for keys %methods;
delete $methods{$_} for grep keys(%{$methods{$_}}) == 1, keys %methods;
- +{ conflicts => \%methods }
+ +{ conflicts => \%methods, requires => [keys %requires] }
};
}
return $composed_name if $COMPOSED{role}{$composed_name};
$me->_install_methods($composed_name, $role);
my $base_name = $composed_name.'::_BASE';
+ # force stash to exist so ->can doesn't complain
+ _getstash($base_name);
# Not using _getglob, since setting @ISA via the typeglob breaks
# inheritance on 5.10.0 if the stash has previously been accessed an
# then a method called on the class (in that order!), which
{ no strict 'refs'; @{"${composed_name}::ISA"} = ( $base_name ); }
my $modifiers = $INFO{$role}{modifiers}||[];
my @mod_base;
- foreach my $modified (
- do { my %h; @h{map $_->[1], @$modifiers} = (); keys %h }
- ) {
+ my @modifiers = grep !$composed_name->can($_),
+ do { my %h; @h{map @{$_}[1..$#$_-1], @$modifiers} = (); keys %h };
+ foreach my $modified (@modifiers) {
push @mod_base, "sub ${modified} { shift->next::method(\@_) }";
}
my $e;
}
die $e if $e;
$me->_install_modifiers($composed_name, $role);
- $COMPOSED{role}{$composed_name} = 1;
+ $COMPOSED{role}{$composed_name} = {
+ modifiers_only => { map { $_ => 1 } @modifiers },
+ };
return $composed_name;
}
sub _check_requires {
- my ($me, $to, $name) = @_;
- return unless my @requires = @{$INFO{$name}{requires}||[]};
+ my ($me, $to, $name, $requires) = @_;
+ return unless my @requires = @{$requires||$INFO{$name}{requires}||[]};
if (my @requires_fail = grep !$to->can($_), @requires) {
# role -> role, add to requires, role -> class, error out
if (my $to_info = $INFO{$to}) {
sub methods_provided_by {
my ($me, $role) = @_;
- die "${role} is not a Role::Tiny" unless my $info = $INFO{$role};
- (keys %{$me->_concrete_methods_of($role)}, @{$info->{requires}||[]});
+ die "${role} is not a Role::Tiny" unless $me->is_role($role);
+ (keys %{$me->_concrete_methods_of($role)}, @{$INFO{$role}->{requires}||[]});
}
sub _install_methods {
foreach my $i (grep !exists $has_methods{$_}, keys %$methods) {
no warnings 'once';
- *{_getglob "${to}::${i}"} = $methods->{$i};
+ my $glob = _getglob "${to}::${i}";
+ *$glob = $methods->{$i};
+
+ # overloads using method names have the method stored in the scalar slot
+ # and &overload::nil in the code slot.
+ next
+ unless $i =~ /^\(/
+ && defined &overload::nil
+ && $methods->{$i} == \&overload::nil;
+
+ my $overload = ${ *{_getglob "${role}::${i}"}{SCALAR} };
+ next
+ unless defined $overload;
+
+ *$glob = \$overload;
}
-
+
$me->_install_does($to);
}
my $FALLBACK = sub { 0 };
sub _install_does {
my ($me, $to) = @_;
-
+
# only add does() method to classes
- return if $INFO{$to};
-
+ return if $me->is_role($to);
+
# add does() only if they don't have one
*{_getglob "${to}::does"} = \&does_role unless $to->can('does');
-
- return if ($to->can('DOES') and $to->can('DOES') != (UNIVERSAL->can('DOES') || 0));
-
+
+ return
+ if $to->can('DOES') and $to->can('DOES') != (UNIVERSAL->can('DOES') || 0);
+
my $existing = $to->can('DOES') || $to->can('isa') || $FALLBACK;
my $new_sub = sub {
my ($proto, $role) = @_;
Role::Tiny::does_role($proto, $role) or $proto->$existing($role);
};
no warnings 'redefine';
- *{_getglob "${to}::DOES"} = $new_sub;
+ return *{_getglob "${to}::DOES"} = $new_sub;
}
sub does_role {
my ($proto, $role) = @_;
- if ($] >= 5.010) {
- require mro;
- } else {
- require MRO::Compat;
- }
+ require(_MRO_MODULE);
foreach my $class (@{mro::get_linear_isa(ref($proto)||$proto)}) {
return 1 if exists $APPLIED_TO{$class}{$role};
}
sub is_role {
my ($me, $role) = @_;
- return !!$INFO{$role};
+ return !!($INFO{$role} && $INFO{$role}{is_role});
}
1;
+__END__
=encoding utf-8
Composes another role into the current role (or class via L<Role::Tiny::With>).
If you have conflicts and want to resolve them in favour of Some::Role1 you
-can instead write:
+can instead write:
with 'Some::Role1';
with 'Some::Role2';
a dependency. If your L<Role::Tiny> role uses modifiers you must depend on
both L<Class::Method::Modifiers> and L<Role::Tiny>.
+=head2 Strict and Warnings
+
+In addition to importing subroutines, using C<Role::Tiny> applies L<strict> and
+L<fatal warnings|perllexwarn/Fatal Warnings> to the caller. It's possible to
+disable these if desired:
+
+ use Role::Tiny;
+ use warnings NONFATAL => 'all';
+
=head1 SUBROUTINES
=head2 does_role
Returns true if the given package is a role.
+=head1 CAVEATS
+
+=over 4
+
+=item * On perl 5.8.8 and earlier, applying a role to an object won't apply any
+overloads from the role to all copies of the object.
+
+=back
+
=head1 SEE ALSO
L<Role::Tiny> is the attribute-less subset of L<Moo::Role>; L<Moo::Role> is
a meta-protocol-less subset of the king of role systems, L<Moose::Role>.
-If you don't want method modifiers and do want to be forcibly restricted
-to a single role application per class, Ovid's L<Role::Basic> exists. But
-Stevan Little (the L<Moose> author) and I don't find the additional
-restrictions to be amazingly helpful in most cases; L<Role::Basic>'s choices
-are more a guide to what you should prefer doing, to our mind, rather than
-something that needs to be enforced.
+Ovid's L<Role::Basic> provides roles with a similar scope, but without method
+modifiers, and having some extra usage restrictions.
=head1 AUTHOR
tobyink - Toby Inkster (cpan:TOBYINK) <tobyink@cpan.org>
+haarg - Graham Knop (cpan:HAARG) <haarg@haarg.org>
+
=head1 COPYRIGHT
Copyright (c) 2010-2012 the Role::Tiny L</AUTHOR> and L</CONTRIBUTORS>