6 MooseX::Types - Organise your Moose types in libraries
13 use Moose::Util::TypeConstraints;
14 use MooseX::Types::TypeDecorator;
15 use MooseX::Types::Base ();
16 use MooseX::Types::Util qw( filter_tags );
17 use MooseX::Types::UndefinedType;
18 use Carp::Clan qw( ^MooseX::Types );
20 use namespace::clean -except => [qw( meta )];
24 my $UndefMsg = q{Action for type '%s' not yet defined in library '%s'};
28 =head2 Library Definition
32 # predeclare our own types
35 PositiveInt NegativeInt
36 ArrayRefOfPositiveInt ArrayRefOfAtLeastThreeNegativeInts
37 LotsOfInnerConstraints StrOrArrayRef
40 # import builtin types
41 use MooseX::Types::Moose 'Int';
47 message { "Int is not larger than 0" };
52 message { "Int is not smaller than 0" };
59 # with parameterized constraints. Please note the containing '(...)'
61 subtype ArrayRefOfPositiveInt,
62 as (ArrayRef[PositiveInt]);
64 subtype ArrayRefOfAtLeastThreeNegativeInts,
65 as (ArrayRef[NegativeInt]),
66 where { scalar(@$_) > 2 };
68 subtype LotsOfInnerConstraints,
69 as (ArrayRef[ArrayRef[HashRef[Int]]]);
71 # with TypeConstraint Unions
73 subtype StrOrArrayRef,
82 use MyLibrary qw( PositiveInt NegativeInt );
84 # use the exported constants as type names
96 print "positive\n" if is_PositiveInt($value);
97 print "negative\n" if is_NegativeInt($value);
99 # coerce the value, NegativeInt doesn't have a coercion
100 # helper, since it didn't define any coercions.
101 $value = to_PositiveInt($value) or die "Cannot coerce";
108 The types provided with L<Moose> are by design global. This package helps
109 you to organise and selectively import your own and the built-in types in
110 libraries. As a nice side effect, it catches typos at compile-time too.
112 However, the main reason for this module is to provide an easy way to not
113 have conflicts with your type names, since the internal fully qualified
114 names of the types will be prefixed with the library's name.
116 This module will also provide you with some helper functions to make it
117 easier to use Moose types in your code.
119 =head1 TYPE HANDLER FUNCTIONS
123 A constant with the name of your type. It contains the type's fully
124 qualified name. Takes no value, as all constants.
128 This handler takes a value and tests if it is a valid value for this
129 C<$type>. It will return true or false.
133 A handler that will take a value and coerce it into the C<$type>. It will
134 return a false value if the type could not be coerced.
136 B<Important Note>: This handler will only be exported for types that can
137 do type coercion. This has the advantage that a coercion to a type that
138 cannot hasn't defined any coercions will lead to a compile-time error.
140 =head1 LIBRARY DEFINITION
142 A MooseX::Types is just a normal Perl module. Unlike Moose
143 itself, it does not install C<use strict> and C<use warnings> in your
144 class by default, so this is up to you.
146 The only thing a library is required to do is
148 use MooseX::Types -declare => \@types;
150 with C<@types> being a list of types you wish to define in this library.
151 This line will install a proper base class in your package as well as the
152 full set of L<handlers|/"TYPE HANDLER FUNCTIONS"> for your declared
153 types. It will then hand control over to L<Moose::Util::TypeConstraints>'
154 C<import> method to export the functions you will need to declare your
157 If you want to use Moose' built-in types (e.g. for subtyping) you will
160 use MooseX::Types::Moose @types;
162 to import the helpers from the shipped L<MooseX::Types::Moose>
163 library which can export all types that come with Moose.
165 You will have to define coercions for your types or your library won't
166 export a L</to_$type> coercion helper for it.
168 Note that you currently cannot define types containing C<::>, since
169 exporting would be a problem.
171 You also don't need to use C<warnings> and C<strict>, since the
172 definition of a library automatically exports those.
176 You can import the L<"type helpers"|/"TYPE HANDLER FUNCTIONS"> of a
177 library by C<use>ing it with a list of types to import as arguments. If
178 you want all of them, use the C<:all> tag. For example:
180 use MyLibrary ':all';
181 use MyOtherLibrary qw( TypeA TypeB );
183 MooseX::Types comes with a library of Moose' built-in types called
184 L<MooseX::Types::Moose>.
186 The exporting mechanism is, since version 0.5, implemented via a wrapper
187 around L<Sub::Exporter>. This means you can do something like this:
189 use MyLibrary TypeA => { -as => 'MyTypeA' },
190 TypeB => { -as => 'MyTypeB' };
192 =head1 WRAPPING A LIBRARY
194 You can define your own wrapper subclasses to manipulate the behaviour
195 of a set of library exports. Here is an example:
200 use base 'MooseX::Types::Wrapper';
202 sub coercion_export_generator {
204 my $code = $class->next::method(@_);
206 my $value = $code->(@_);
207 warn "Coercion returned undef!"
208 unless defined $value;
215 This class wraps the coercion generator (e.g., C<to_Int()>) and warns
216 if a coercion returned an undefined value. You can wrap any library
221 use MyWrapper MyLibrary => [qw( Foo Bar )],
222 Moose => [qw( Str Int )];
227 The C<Moose> library name is a special shortcut for
228 L<MooseX::Types::Moose>.
230 =head2 Generator methods you can overload
234 =item type_export_generator( $short, $full )
236 Creates a closure returning the type's L<Moose::Meta::TypeConstraint>
239 =item check_export_generator( $short, $full, $undef_message )
241 This creates the closure used to test if a value is valid for this type.
243 =item coercion_export_generator( $short, $full, $undef_message )
245 This is the closure that's doing coercions.
249 =head2 Provided Parameters
255 The short, exported name of the type.
259 The fully qualified name of this type as L<Moose> knows it.
263 A message that will be thrown when type functionality is used but the
264 type does not yet exist.
268 =head1 NOTES REGARDING PARAMETERIZED CONSTRAINTS
270 L<MooseX::Types> uses L<MooseX::Types::TypeDecorator> to do some overloading
271 which generally allows you to easily create types with parameters such as:
273 subtype ParameterType,
276 However, due to an outstanding issue you will need to wrap the parameterized
277 type inside parenthesis, as in the example above. Hopefully this limitation
278 will be lifted in a future version of this module.
280 If you are using paramterized types in the options section of an attribute
281 declaration, the parenthesis are not needed:
284 use MooseX::Types::Moose qw(HashRef Int);
286 has 'attr' => (isa=>HashRef[Str]);
288 =head1 NOTES REGARDING TYPE UNIONS
290 L<MooseX::Types> uses L<MooseX::Types::TypeDecorator> to do some overloading
291 which generally allows you to easily create union types:
293 subtype StrOrArrayRef,
296 As with parameterized constrains, this overloading extends to modules using the
297 types you define in a type library.
300 use MooseX::Types::Moose qw(HashRef Int);
302 has 'attr' => (isa=>HashRef|Int);
304 And everything should just work as you'd think.
310 Installs the L<MooseX::Types::Base> class into the caller and
311 exports types according to the specification described in
312 L</"LIBRARY DEFINITION">. This will continue to
313 L<Moose::Util::TypeConstraints>' C<import> method to export helper
314 functions you will need to declare your types.
319 my ($class, %args) = @_;
322 # everyone should want this
326 # inject base class into new library
328 unshift @{ $callee . '::ISA' }, 'MooseX::Types::Base';
331 # generate predeclared type helpers
332 if (my @orig_declare = @{ $args{ -declare } || [] }) {
333 my ($tags, $declare) = filter_tags @orig_declare;
336 for my $type (@$declare) {
338 croak "Cannot create a type containing '::' ($type) at the moment"
341 # add type to library and remember to export
342 $callee->add_type($type);
343 push @to_export, $type;
346 $callee->import({ -full => 1, -into => $callee }, @to_export);
349 # run type constraints import
350 return Moose::Util::TypeConstraints->import({ into => $callee });
353 =head2 type_export_generator
355 Generate a type export, e.g. C<Int()>. This will return either a
356 L<Moose::Meta::TypeConstraint> object, or alternatively a
357 L<MooseX::Types::UndefinedType> object if the type was not
362 sub type_export_generator {
363 my ($class, $type, $name) = @_;
366 if(defined(my $params = shift @_)) {
367 if(ref $params eq 'ARRAY') {
368 $type_constraint = $class->create_arged_type_constraint($name, @$params);
370 croak 'Arguments must be an ArrayRef, not '. ref $params;
373 $type_constraint = $class->create_base_type_constraint($name);
375 $type_constraint = defined($type_constraint) ? $type_constraint
376 : MooseX::Types::UndefinedType->new($name);
378 return $class->create_type_decorator($type_constraint);
383 =head2 create_arged_type_constraint ($name, @args)
385 Given a String $name with @args find the matching typeconstraint.
389 sub create_arged_type_constraint {
390 my ($class, $name, @args) = @_;
391 my $type_constraint = Moose::Util::TypeConstraints::find_or_create_type_constraint($name);
392 return $type_constraint->parameterize(@args)
395 =head2 create_base_type_constraint ($name)
397 Given a String $name, find the matching typeconstraint.
401 sub create_base_type_constraint {
402 my ($class, $name) = @_;
403 return find_type_constraint($name);
406 =head2 create_type_decorator ($type_constraint)
408 Given a $type_constraint, return a lightweight L<MooseX::Types::TypeDecorator>
413 sub create_type_decorator {
414 my ($class, $type_constraint) = @_;
415 return MooseX::Types::TypeDecorator->new($type_constraint);
418 =head2 coercion_export_generator
420 This generates a coercion handler function, e.g. C<to_Int($value)>.
424 sub coercion_export_generator {
425 my ($class, $type, $full, $undef_msg) = @_;
429 # we need a type object
430 my $tobj = find_type_constraint($full) or croak $undef_msg;
431 my $return = $tobj->coerce($value);
433 # non-successful coercion returns false
434 return unless $tobj->check($return);
440 =head2 check_export_generator
442 Generates a constraint check closure, e.g. C<is_Int($value)>.
446 sub check_export_generator {
447 my ($class, $type, $full, $undef_msg) = @_;
451 # we need a type object
452 my $tobj = find_type_constraint($full) or croak $undef_msg;
454 return $tobj->check($value);
460 A library makes the types quasi-unique by prefixing their names with (by
461 default) the library package name. If you're only using the type handler
462 functions provided by MooseX::Types, you shouldn't ever have to use
463 a type's actual full name.
468 L<Moose::Util::TypeConstraints>,
469 L<MooseX::Types::Moose>,
472 =head1 AUTHOR AND COPYRIGHT
474 Robert 'phaylon' Sedlacek C<E<lt>rs@474.atE<gt>>, with many thanks to
475 the C<#moose> cabal on C<irc.perl.org>.
477 Additional features by John Napiorkowski (jnapiorkowski) <jjnapiork@cpan.org>.
481 This program is free software; you can redistribute it and/or modify
482 it under the same terms as perl itself.