use strict;
use warnings FATAL => 'all';
-our $VERSION = '1.000_900'; # 1.0.900
+our $VERSION = '1.002005'; # 1.2.5
$VERSION = eval $VERSION;
our %INFO;
our %APPLIED_TO;
our %COMPOSED;
-our %UNION_INFO;
+our %COMPOSITE_INFO;
# Module state workaround totally stolen from Zefram's Module::Runtime.
strict->import;
warnings->import(FATAL => 'all');
return if $INFO{$target}; # already exported into this package
+ $INFO{$target}{is_role} = 1;
# get symbol table reference
- my $stash = do { no strict 'refs'; \%{"${target}::"} };
+ my $stash = _getstash($target);
# install before/after/around subs
foreach my $type (qw(before after around)) {
*{_getglob "${target}::${type}"} = sub {
require Class::Method::Modifiers;
push @{$INFO{$target}{modifiers}||=[]}, [ $type => @_ ];
+ return;
};
}
*{_getglob "${target}::requires"} = sub {
push @{$INFO{$target}{requires}||=[]}, @_;
+ return;
};
*{_getglob "${target}::with"} = sub {
- $me->apply_union_of_roles_to_package($target, @_);
+ $me->apply_roles_to_package($target, @_);
+ return;
};
# grab all *non-constant* (stash slot is not a scalarref) subs present
# in the symbol table and store their refaddrs (no need to forcibly
- # inflate constant subs into real subs) - also add '' to here (this
- # is used later)
- @{$INFO{$target}{not_methods}={}}{
- '', map { *$_{CODE}||() } grep !ref($_), values %$stash
- } = ();
+ # inflate constant subs into real subs) with a map to the coderefs in
+ # case of copying or re-use
+ my @not_methods = (map { *$_{CODE}||() } grep !ref($_), values %$stash);
+ @{$INFO{$target}{not_methods}={}}{@not_methods} = @not_methods;
# a role does itself
$APPLIED_TO{$target} = { $target => undef };
}
-sub apply_role_to_package {
+sub role_application_steps {
+ qw(_install_methods _check_requires _install_modifiers _copy_applied_list);
+}
+
+sub apply_single_role_to_package {
my ($me, $to, $role) = @_;
_load_module($role);
die "This is apply_role_to_package" if ref($to);
- die "${role} is not a Role::Tiny" unless my $info = $INFO{$role};
-
- $me->_check_requires($to, $role, @{$info->{requires}||[]});
+ die "${role} is not a Role::Tiny" unless $INFO{$role};
- $me->_install_methods($to, $role);
-
- $me->_install_modifiers($to, $info->{modifiers});
-
- # only add does() method to classes and only if they don't have one
- if (not $INFO{$to} and not $to->can('does')) {
- *{_getglob "${to}::does"} = \&does_role;
+ foreach my $step ($me->role_application_steps) {
+ $me->$step($to, $role);
}
+}
+sub _copy_applied_list {
+ my ($me, $to, $role) = @_;
# copy our role list into the target's
@{$APPLIED_TO{$to}||={}}{keys %{$APPLIED_TO{$role}}} = ();
}
die "No roles supplied!" unless @roles;
+ _load_module($superclass);
{
my %seen;
$seen{$_}++ for @roles;
require MRO::Compat;
}
+ my %conflicts = %{$me->_composite_info_for(@roles)->{conflicts}};
+ if (keys %conflicts) {
+ my $fail =
+ join "\n",
+ map {
+ "Method name conflict for '$_' between roles "
+ ."'".join(' and ', sort values %{$conflicts{$_}})."'"
+ .", cannot apply these simultaneously to an object."
+ } keys %conflicts;
+ die $fail;
+ }
+
my @composable = map $me->_composable_package_for($_), reverse @roles;
*{_getglob("${new_name}::ISA")} = [ @composable, $superclass ];
do { my %h; @h{map @{$_->{requires}||[]}, @info} = (); keys %h }
);
- *{_getglob "${new_name}::does"} = \&does_role unless $new_name->can('does');
-
@{$APPLIED_TO{$new_name}||={}}{
map keys %{$APPLIED_TO{$_}}, @roles
} = ();
return $new_name;
}
-sub apply_union_of_roles_to_package {
+# preserved for compat, and apply_roles_to_package calls it to allow an
+# updated Role::Tiny to use a non-updated Moo::Role
+
+sub apply_role_to_package { shift->apply_single_role_to_package(@_) }
+
+sub apply_roles_to_package {
my ($me, $to, @roles) = @_;
return $me->apply_role_to_package($to, $roles[0]) if @roles == 1;
- my %conflicts = %{$me->_union_info_for(@roles)->{conflicts}};
- delete $conflicts{$_} for $me->_concrete_methods_of($to);
+ my %conflicts = %{$me->_composite_info_for(@roles)->{conflicts}};
+ delete $conflicts{$_} for keys %{ $me->_concrete_methods_of($to) };
if (keys %conflicts) {
my $fail =
join "\n",
} keys %conflicts;
die $fail;
}
- $me->apply_role_to_package($to, $_) for @roles;
+
+ # 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
+ }
+
+ # 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) {
+ $me->apply_single_role_to_package($to, $role);
+ }
+ }
+ else {
+ foreach my $step ($me->role_application_steps) {
+ foreach my $role (@roles) {
+ $me->$step($to, $role);
+ }
+ }
+ }
$APPLIED_TO{$to}{join('|',@roles)} = 1;
}
-sub _union_info_for {
+sub _composite_info_for {
my ($me, @roles) = @_;
- $UNION_INFO{join('|', sort @roles)} ||= do {
- _load_module($_) for @roles;
+ $COMPOSITE_INFO{join('|', sort @roles)} ||= do {
+ foreach my $role (@roles) {
+ _load_module($role);
+ }
my %methods;
foreach my $role (@roles) {
my $this_methods = $me->_concrete_methods_of($role);
return $composed_name if $COMPOSED{role}{$composed_name};
$me->_install_methods($composed_name, $role);
my $base_name = $composed_name.'::_BASE';
- *{_getglob("${composed_name}::ISA")} = [ $base_name ];
+ # Not using _getglob, since setting @ISA via the typeglob breaks
+ # inheritance on 5.10.0 if the stash has previously been accessed an
+ # then a method called on the class (in that order!), which
+ # ->_install_methods (with the help of ->_install_does) ends up doing.
+ { no strict 'refs'; @{"${composed_name}::ISA"} = ( $base_name ); }
my $modifiers = $INFO{$role}{modifiers}||[];
my @mod_base;
foreach my $modified (
$e = "Evaling failed: $@\nTrying to eval:\n${code}" if $@;
}
die $e if $e;
- $me->_install_modifiers($composed_name, $modifiers);
+ $me->_install_modifiers($composed_name, $role);
$COMPOSED{role}{$composed_name} = 1;
return $composed_name;
}
sub _check_requires {
- my ($me, $to, $name, @requires) = @_;
+ my ($me, $to, $name) = @_;
+ return unless my @requires = @{$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}) {
my ($me, $role) = @_;
my $info = $INFO{$role};
# grab role symbol table
- my $stash = do { no strict 'refs'; \%{"${role}::"}};
- my $not_methods = $info->{not_methods};
- +{
+ my $stash = _getstash($role);
+ # reverse so our keys become the values (captured coderefs) in case
+ # they got copied or re-used since
+ my $not_methods = { reverse %{$info->{not_methods}||{}} };
+ $info->{methods} ||= +{
# grab all code entries that aren't in the not_methods list
map {
my $code = *{$stash->{$_}}{CODE};
- # rely on the '' key we added in import for "no code here"
- exists $not_methods->{$code||''} ? () : ($_ => $code)
+ ( ! $code or exists $not_methods->{$code} ) ? () : ($_ => $code)
} grep !ref($stash->{$_}), keys %$stash
};
}
my $methods = $me->_concrete_methods_of($role);
# grab target symbol table
- my $stash = do { no strict 'refs'; \%{"${to}::"}};
+ my $stash = _getstash($to);
# determine already extant methods of target
my %has_methods;
no warnings 'once';
*{_getglob "${to}::${i}"} = $methods->{$i};
}
+
+ $me->_install_does($to);
}
sub _install_modifiers {
- my ($me, $to, $modifiers) = @_;
+ my ($me, $to, $name) = @_;
+ return unless my $modifiers = $INFO{$name}{modifiers};
if (my $info = $INFO{$to}) {
push @{$info->{modifiers}}, @{$modifiers||[]};
} else {
}
}
+my $vcheck_error;
+
sub _install_single_modifier {
my ($me, @args) = @_;
+ defined($vcheck_error) or $vcheck_error = do {
+ local $@;
+ eval { Class::Method::Modifiers->VERSION(1.05); 1 }
+ ? 0
+ : $@
+ };
+ $vcheck_error and die $vcheck_error;
Class::Method::Modifiers::install_modifier(@args);
}
+my $FALLBACK = sub { 0 };
+sub _install_does {
+ my ($me, $to) = @_;
+
+ # only add does() method to classes
+ return if $INFO{$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));
+
+ 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"} = $new_sub;
+}
+
sub does_role {
my ($proto, $role) = @_;
- return exists $APPLIED_TO{ref($proto)||$proto}{$role};
+ if ($] >= 5.010) {
+ require mro;
+ } else {
+ require MRO::Compat;
+ }
+ foreach my $class (@{mro::get_linear_isa(ref($proto)||$proto)}) {
+ return 1 if exists $APPLIED_TO{$class}{$role};
+ }
+ return 0;
+}
+
+sub is_role {
+ my ($me, $role) = @_;
+ return !!$INFO{$role};
}
1;
+=encoding utf-8
+
=head1 NAME
Role::Tiny - Roles. Like a nouvelle cuisine portion size slice of Moose.
=back
Unlike L<Class::C3>, where the B<last> class inherited from "wins," role
-composition is the other way around, where first wins. In a more complete
-system (see L<Moose>) roles are checked to see if they clash. The goal of this
-is to be much simpler, hence disallowing composition of multiple roles at once.
-
-=head1 METHODS
-
-=head2 apply_role_to_package
-
- Role::Tiny->apply_role_to_package('Some::Package', 'Some::Role');
-
-Composes role with package. See also L<Role::Tiny::With>.
-
-=head2 apply_roles_to_object
-
- Role::Tiny->apply_roles_to_object($foo, qw(Some::Role1 Some::Role2));
-
-Composes roles in order into object directly. Object is reblessed into the
-resulting class.
-
-=head2 create_class_with_roles
-
- Role::Tiny->create_class_with_roles('Some::Base', qw(Some::Role1 Some::Role2));
-
-Creates a new class based on base, with the roles composed into it in order.
-New class is returned.
-
-=head1 SUBROUTINES
-
-=head2 does_role
-
- if (Role::Tiny::does_role($foo, 'Some::Role')) {
- ...
- }
-
-Returns true if class has been composed with role.
-
-This subroutine is also installed as ->does on any class a Role::Tiny is
-composed into unless that class already has an ->does method, so
-
- if ($foo->does('Some::Role')) {
- ...
- }
-
-will work for classes but to test a role, one must use ::does_role directly
+composition is the other way around, where the class wins. If multiple roles
+are applied in a single call (single with statement), then if any of their
+provided methods clash, an exception is raised unless the class provides
+a method since this conflict indicates a potential problem.
=head1 IMPORTED SUBROUTINES
=head2 with
with 'Some::Role1';
+
+ with 'Some::Role1', 'Some::Role2';
+
+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:
+
+ with 'Some::Role1';
with 'Some::Role2';
-Composes another role into the current role. Only one role may be composed in
-at a time to allow the code to remain as simple as possible.
+If you have conflicts and want to resolve different conflicts in favour of
+different roles, please refactor your codebase.
=head2 before
a dependency. If your L<Role::Tiny> role uses modifiers you must depend on
both L<Class::Method::Modifiers> and L<Role::Tiny>.
+=head1 SUBROUTINES
+
+=head2 does_role
+
+ if (Role::Tiny::does_role($foo, 'Some::Role')) {
+ ...
+ }
+
+Returns true if class has been composed with role.
+
+This subroutine is also installed as ->does on any class a Role::Tiny is
+composed into unless that class already has an ->does method, so
+
+ if ($foo->does('Some::Role')) {
+ ...
+ }
+
+will work for classes but to test a role, one must use ::does_role directly.
+
+Additionally, Role::Tiny will override the standard Perl C<DOES> method
+for your class. However, if C<any> class in your class' inheritance
+hierarchy provides C<DOES>, then Role::Tiny will not override it.
+
+=head1 METHODS
+
+=head2 apply_roles_to_package
+
+ Role::Tiny->apply_roles_to_package(
+ 'Some::Package', 'Some::Role', 'Some::Other::Role'
+ );
+
+Composes role with package. See also L<Role::Tiny::With>.
+
+=head2 apply_roles_to_object
+
+ Role::Tiny->apply_roles_to_object($foo, qw(Some::Role1 Some::Role2));
+
+Composes roles in order into object directly. Object is reblessed into the
+resulting class.
+
+=head2 create_class_with_roles
+
+ Role::Tiny->create_class_with_roles('Some::Base', qw(Some::Role1 Some::Role2));
+
+Creates a new class based on base, with the roles composed into it in order.
+New class is returned.
+
+=head2 is_role
+
+ Role::Tiny->is_role('Some::Role1')
+
+Returns true if the given package is a role.
+
=head1 SEE ALSO
L<Role::Tiny> is the attribute-less subset of L<Moo::Role>; L<Moo::Role> is
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 are both still convinced that
-he's Doing It Wrong.
+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.
=head1 AUTHOR
perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>
+Mithaldu - Christian Walde (cpan:MITHALDU) <walde.christian@googlemail.com>
+
+ilmari - Dagfinn Ilmari Mannsåker (cpan:ILMARI) <ilmari@ilmari.org>
+
+tobyink - Toby Inkster (cpan:TOBYINK) <tobyink@cpan.org>
+
=head1 COPYRIGHT
Copyright (c) 2010-2012 the Role::Tiny L</AUTHOR> and L</CONTRIBUTORS>
projects / gitmo/Role-Tiny.git / blobdiff