Moo::Role(3) User Contributed Perl Documentation Moo::Role(3)NAME
Moo::Role - Minimal Object Orientation support for Roles
SYNOPSIS
package My::Role;
use Moo::Role;
sub foo { ... }
sub bar { ... }
has baz => (
is => 'ro',
);
1;
And elsewhere:
package Some::Class;
use Moo;
# bar gets imported, but not foo
with('My::Role');
sub foo { ... }
1;
DESCRIPTION
"Moo::Role" builds upon Role::Tiny, so look there for most of the documentation on how this works. The main addition here is extra bits to
make the roles more "Moosey;" which is to say, it adds "has".
IMPORTED SUBROUTINES
See "IMPORTED SUBROUTINES" in Role::Tiny for all the other subroutines that are imported by this module.
has
has attr => (
is => 'ro',
);
Declares an attribute for the class to be composed into. See "has" in Moo for all options.
AUTHORS
See Moo for authors.
COPYRIGHT AND LICENSE
See Moo for the copyright and license.
perl v5.16.2 2012-10-08 Moo::Role(3)
Check Out this Related Man Page
Role::Tiny(3) User Contributed Perl Documentation Role::Tiny(3)NAME
Role::Tiny - Roles. Like a nouvelle cuisine portion size slice of Moose.
SYNOPSIS
package Some::Role;
use Role::Tiny;
sub foo { ... }
sub bar { ... }
around baz => sub { ... }
1;
else where
package Some::Class;
use Role::Tiny::With;
# bar gets imported, but not foo
with 'Some::Role';
sub foo { ... }
# baz is wrapped in the around modifier by Class::Method::Modifiers
sub baz { ... }
1;
If you wanted attributes as well, look at Moo::Role.
DESCRIPTION
"Role::Tiny" is a minimalist role composition tool.
ROLE COMPOSITION
Role composition can be thought of as much more clever and meaningful multiple inheritance. The basics of this implementation of roles is:
o If a method is already defined on a class, that method will not be composed in from the role.
o If a method that the role "requires" to be implemented is not implemented, role application will fail loudly.
Unlike Class::C3, where the last class inherited from "wins," role 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.
IMPORTED SUBROUTINES
requires
requires qw(foo bar);
Declares a list of methods that must be defined to compose role.
with
with 'Some::Role1';
with 'Some::Role1', 'Some::Role2';
Composes another role into the current role (or class via 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';
If you have conflicts and want to resolve different conflicts in favour of different roles, please refactor your codebase.
before
before foo => sub { ... };
See "before method(s) => sub { ... }" in Class::Method::Modifiers for full documentation.
Note that since you are not required to use method modifiers, Class::Method::Modifiers is lazily loaded and we do not declare it as a
dependency. If your Role::Tiny role uses modifiers you must depend on both Class::Method::Modifiers and Role::Tiny.
around
around foo => sub { ... };
See "around method(s) => sub { ... }" in Class::Method::Modifiers for full documentation.
Note that since you are not required to use method modifiers, Class::Method::Modifiers is lazily loaded and we do not declare it as a
dependency. If your Role::Tiny role uses modifiers you must depend on both Class::Method::Modifiers and Role::Tiny.
after
after foo => sub { ... };
See "after method(s) => sub { ... }" in Class::Method::Modifiers for full documentation.
Note that since you are not required to use method modifiers, Class::Method::Modifiers is lazily loaded and we do not declare it as a
dependency. If your Role::Tiny role uses modifiers you must depend on both Class::Method::Modifiers and Role::Tiny.
SUBROUTINES
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 "DOES" method for your class. However, if "any" class in your class' inheritance
hierarchy provides "DOES", then Role::Tiny will not override it.
METHODS
apply_roles_to_package
Role::Tiny->apply_roles_to_package(
'Some::Package', 'Some::Role', 'Some::Other::Role'
);
Composes role with package. See also Role::Tiny::With.
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.
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.
is_role
Role::Tiny->is_role('Some::Role1')
Returns true if the given package is a role.
SEE ALSO
Role::Tiny is the attribute-less subset of Moo::Role; Moo::Role is a meta-protocol-less subset of the king of role systems, 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 Role::Basic exists.
But Stevan Little (the Moose author) and I don't find the additional restrictions to be amazingly helpful in most cases; 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.
AUTHOR
mst - Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
CONTRIBUTORS
dg - David Leadbeater (cpan:DGL) <dgl@dgl.cx>
frew - Arthur Axel "fREW" Schmidt (cpan:FREW) <frioux@gmail.com>
hobbs - Andrew Rodland (cpan:ARODLAND) <arodland@cpan.org>
jnap - John Napiorkowski (cpan:JJNAPIORK) <jjn1056@yahoo.com>
ribasushi - Peter Rabbitson (cpan:RIBASUSHI) <ribasushi@cpan.org>
chip - Chip Salzenberg (cpan:CHIPS) <chip@pobox.com>
ajgb - Alex J. G. BurzyXski (cpan:AJGB) <ajgb@cpan.org>
doy - Jesse Luehrs (cpan:DOY) <doy at tozt dot net>
perigrin - Chris Prather (cpan:PERIGRIN) <chris@prather.org>
Mithaldu - Christian Walde (cpan:MITHALDU) <walde.christian@googlemail.com>
ilmari - Dagfinn Ilmari Mannsaaker (cpan:ILMARI) <ilmari@ilmari.org>
tobyink - Toby Inkster (cpan:TOBYINK) <tobyink@cpan.org>
COPYRIGHT
Copyright (c) 2010-2012 the Role::Tiny "AUTHOR" and "CONTRIBUTORS" as listed above.
LICENSE
This library is free software and may be distributed under the same terms as perl itself.
perl v5.18.2 2013-09-04 Role::Tiny(3)