6 MooseX::Types - Organise your Moose types in libraries
13 use Moose::Util::TypeConstraints;
14 use MooseX::Types::Base ();
15 use MooseX::Types::Util qw( filter_tags );
16 use MooseX::Types::UndefinedType;
17 use Carp::Clan qw( ^MooseX::Types );
19 use namespace::clean -except => [qw( meta )];
23 my $UndefMsg = q{Action for type '%s' not yet defined in library '%s'};
27 =head2 Library Definition
31 # predeclare our own types
33 -declare => [qw( PositiveInt NegativeInt )];
35 # import builtin types
36 use MooseX::Types::Moose 'Int';
42 message { "Int is not larger than 0" };
47 message { "Int is not smaller than 0" };
60 use MyLibrary qw( PositiveInt NegativeInt );
62 # use the exported constants as type names
74 print "positive\n" if is_PositiveInt($value);
75 print "negative\n" if is_NegativeInt($value);
77 # coerce the value, NegativeInt doesn't have a coercion
78 # helper, since it didn't define any coercions.
79 $value = to_PositiveInt($value) or die "Cannot coerce";
86 The types provided with L<Moose> are by design global. This package helps
87 you to organise and selectively import your own and the built-in types in
88 libraries. As a nice side effect, it catches typos at compile-time too.
90 However, the main reason for this module is to provide an easy way to not
91 have conflicts with your type names, since the internal fully qualified
92 names of the types will be prefixed with the library's name.
94 This module will also provide you with some helper functions to make it
95 easier to use Moose types in your code.
97 =head1 TYPE HANDLER FUNCTIONS
101 A constant with the name of your type. It contains the type's fully
102 qualified name. Takes no value, as all constants.
106 This handler takes a value and tests if it is a valid value for this
107 C<$type>. It will return true or false.
111 A handler that will take a value and coerce it into the C<$type>. It will
112 return a false value if the type could not be coerced.
114 B<Important Note>: This handler will only be exported for types that can
115 do type coercion. This has the advantage that a coercion to a type that
116 cannot hasn't defined any coercions will lead to a compile-time error.
118 =head1 LIBRARY DEFINITION
120 A MooseX::Types is just a normal Perl module. Unlike Moose
121 itself, it does not install C<use strict> and C<use warnings> in your
122 class by default, so this is up to you.
124 The only thing a library is required to do is
126 use MooseX::Types -declare => \@types;
128 with C<@types> being a list of types you wish to define in this library.
129 This line will install a proper base class in your package as well as the
130 full set of L<handlers|/"TYPE HANDLER FUNCTIONS"> for your declared
131 types. It will then hand control over to L<Moose::Util::TypeConstraints>'
132 C<import> method to export the functions you will need to declare your
135 If you want to use Moose' built-in types (e.g. for subtyping) you will
138 use MooseX::Types::Moose @types;
140 to import the helpers from the shipped L<MooseX::Types::Moose>
141 library which can export all types that come with Moose.
143 You will have to define coercions for your types or your library won't
144 export a L</to_$type> coercion helper for it.
146 Note that you currently cannot define types containing C<::>, since
147 exporting would be a problem.
149 You also don't need to use C<warnings> and C<strict>, since the
150 definition of a library automatically exports those.
154 You can import the L<"type helpers"|/"TYPE HANDLER FUNCTIONS"> of a
155 library by C<use>ing it with a list of types to import as arguments. If
156 you want all of them, use the C<:all> tag. For example:
158 use MyLibrary ':all';
159 use MyOtherLibrary qw( TypeA TypeB );
161 MooseX::Types comes with a library of Moose' built-in types called
162 L<MooseX::Types::Moose>.
164 The exporting mechanism is, since version 0.5, implemented via a wrapper
165 around L<Sub::Exporter>. This means you can do something like this:
167 use MyLibrary TypeA => { -as => 'MyTypeA' },
168 TypeB => { -as => 'MyTypeB' };
170 =head1 WRAPPING A LIBRARY
172 You can define your own wrapper subclasses to manipulate the behaviour
173 of a set of library exports. Here is an example:
178 use base 'MooseX::Types::Wrapper';
180 sub coercion_export_generator {
182 my $code = $class->next::method(@_);
184 my $value = $code->(@_);
185 warn "Coercion returned undef!"
186 unless defined $value;
193 This class wraps the coercion generator (e.g., C<to_Int()>) and warns
194 if a coercion returned an undefined value. You can wrap any library
199 use MyWrapper MyLibrary => [qw( Foo Bar )],
200 Moose => [qw( Str Int )];
205 The C<Moose> library name is a special shortcut for
206 L<MooseX::Types::Moose>.
208 =head2 Generator methods you can overload
212 =item type_export_generator( $short, $full )
214 Creates a closure returning the type's L<Moose::Meta::TypeConstraint>
217 =item check_export_generator( $short, $full, $undef_message )
219 This creates the closure used to test if a value is valid for this type.
221 =item coercion_export_generator( $short, $full, $undef_message )
223 This is the closure that's doing coercions.
227 =head2 Provided Parameters
233 The short, exported name of the type.
237 The fully qualified name of this type as L<Moose> knows it.
241 A message that will be thrown when type functionality is used but the
242 type does not yet exist.
250 Installs the L<MooseX::Types::Base> class into the caller and
251 exports types according to the specification described in
252 L</"LIBRARY DEFINITION">. This will continue to
253 L<Moose::Util::TypeConstraints>' C<import> method to export helper
254 functions you will need to declare your types.
259 my ($class, %args) = @_;
262 # everyone should want this
266 # inject base class into new library
268 unshift @{ $callee . '::ISA' }, 'MooseX::Types::Base';
271 # generate predeclared type helpers
272 if (my @orig_declare = @{ $args{ -declare } || [] }) {
273 my ($tags, $declare) = filter_tags @orig_declare;
276 for my $type (@$declare) {
278 croak "Cannot create a type containing '::' ($type) at the moment"
281 # add type to library and remember to export
282 $callee->add_type($type);
283 push @to_export, $type;
286 $callee->import({ -full => 1, -into => $callee }, @to_export);
289 # run type constraints import
290 return Moose::Util::TypeConstraints->import({ into => $callee });
293 =head2 type_export_generator
295 Generate a type export, e.g. C<Int()>. This will return either a
296 L<Moose::Meta::TypeConstraint> object, or alternatively a
297 L<MooseX::Types::UndefinedType> object if the type was not
302 sub type_export_generator {
303 my ($class, $type, $full) = @_;
305 return find_type_constraint($full)
306 || MooseX::Types::UndefinedType->new($full);
310 =head2 coercion_export_generator
312 This generates a coercion handler function, e.g. C<to_Int($value)>.
316 sub coercion_export_generator {
317 my ($class, $type, $full, $undef_msg) = @_;
321 # we need a type object
322 my $tobj = find_type_constraint($full) or croak $undef_msg;
323 my $return = $tobj->coerce($value);
325 # non-successful coercion returns false
326 return unless $tobj->check($return);
332 =head2 check_export_generator
334 Generates a constraint check closure, e.g. C<is_Int($value)>.
338 sub check_export_generator {
339 my ($class, $type, $full, $undef_msg) = @_;
343 # we need a type object
344 my $tobj = find_type_constraint($full) or croak $undef_msg;
346 return $tobj->check($value);
352 A library makes the types quasi-unique by prefixing their names with (by
353 default) the library package name. If you're only using the type handler
354 functions provided by MooseX::Types, you shouldn't ever have to use
355 a type's actual full name.
360 L<Moose::Util::TypeConstraints>,
361 L<MooseX::Types::Moose>,
364 =head1 AUTHOR AND COPYRIGHT
366 Robert 'phaylon' Sedlacek C<E<lt>rs@474.atE<gt>>, with many thanks to
367 the C<#moose> cabal on C<irc.perl.org>.
371 This program is free software; you can redistribute it and/or modify
372 it under the same terms as perl itself.