1 package ## Hide from PAUSE
2 MooseX::Meta::TypeConstraint::Dependent;
5 use Moose::Util::TypeConstraints ();
6 use MooseX::Meta::TypeCoercion::Dependent;
7 extends 'Moose::Meta::TypeConstraint';
11 MooseX::Meta::TypeConstraint::Dependent - Metaclass for Dependent type constraints.
15 see L<MooseX::Types::Dependent> for examples and details of how to use dependent
16 types. This class is a subclass of L<Moose::Meta::TypeConstraint> which
17 provides the gut functionality to enable dependent type constraints.
21 This class defines the following attributes.
23 =head2 dependent_type_constraint
25 The type constraint whose validity is being made dependent on a value that is a
26 L</constraining_type_constraint>
30 has 'dependent_type_constraint' => (
33 predicate=>'has_dependent_type_constraint',
36 check_dependent=>'check',
40 =head2 constraining_type_constraint
42 This is a type constraint which defines what kind of value is allowed to be the
43 constraining value of the depending type.
47 has 'constraining_type_constraint' => (
50 predicate=>'has_constraining_type_constraint',
53 check_constraining=>'check',
57 =head2 comparison_callback
59 This is a callback which returns a boolean value. It get's passed the value
60 L</constraining_type_constraint> validates as well as the check value.
62 This callback is executed in addition to anything you put into a 'where' clause.
63 However, the 'where' clause only get's the check value.
65 Exercise some sanity, this should be limited to actual comparision operations,
66 not as a sneaky way to mess with the constraining value.
70 has 'comparison_callback' => (
73 predicate=>'has_comparison_callback',
77 =head2 constraint_generator
79 A subref or closure that contains the way we validate incoming values against
80 a set of type constraints.
84 has 'constraint_generator' => (
87 predicate=>'has_constraint_generator',
93 This class defines the following methods.
101 around 'new' => sub {
102 my ($new, $class, @args) = @_;
103 my $self = $class->$new(@args);
104 $self->coercion(MooseX::Meta::TypeCoercion::Dependent->new(
105 type_constraint => $self,
110 =head2 check($check_value, $constraining_value)
112 Make sure when properly dispatch all the right values to the right spots
116 around 'check' => sub {
117 my ($check, $self, @args) = @_;
118 return $self->$check(@args);
121 =head2 generate_constraint_for ($type_constraints)
123 Given some type constraints, use them to generate validation rules for an ref
124 of values (to be passed at check time)
128 sub generate_constraint_for {
129 my ($self, $callback, $constraining) = @_;
131 my ($dependent_pair) = @_;
132 my ($check_value, $constraining_value) = @$dependent_pair;
134 ## First need to test the bits
135 unless($self->check_dependent($check_value)) {
139 unless($self->check_constraining($constraining_value)) {
143 my $constraint_generator = $self->constraint_generator;
144 return $constraint_generator->(
152 =head2 parameterize ($dependent, $callback, $constraining)
154 Given a ref of type constraints, create a structured type.
159 my ($self, $dependent, $callback, $constraining) = @_;
160 my $class = ref $self;
161 my $name = $self->_generate_subtype_name($dependent, $callback, $constraining);
162 my $constraint_generator = $self->__infer_constraint_generator;
167 dependent_type_constraint=>$dependent,
168 comparison_callback=>$callback,
169 constraint_generator => $constraint_generator,
170 constraining_type_constraint => $constraining,
174 =head2 _generate_subtype_name
176 Returns a name for the dependent type that should be unique
180 sub _generate_subtype_name {
181 my ($self, $dependent, $callback, $constraining) = @_;
183 "%s_depends_on_%s_via_%s",
184 $dependent, $constraining, $callback
188 =head2 __infer_constraint_generator
190 This returns a CODEREF which generates a suitable constraint generator. Not
191 user servicable, you'll never call this directly.
193 TBD, this is definitely going to need some work.
197 sub __infer_constraint_generator {
199 if($self->has_constraint_generator) {
200 return $self->constraint_generator;
203 ## I'm not sure about this stuff but everything seems to work
207 $self->comparison_callback,
208 $self->constraining_type_constraint,
211 $self->constraint->($merged_tc, @_);
216 =head2 compile_type_constraint
218 hook into compile_type_constraint so we can set the correct validation rules.
222 around 'compile_type_constraint' => sub {
223 my ($compile_type_constraint, $self) = @_;
225 if($self->has_comparison_callback &&
226 $self->has_constraining_type_constraint) {
227 my $generated_constraint = $self->generate_constraint_for(
228 $self->comparison_callback,
229 $self->constraining_type_constraint,
231 $self->_set_constraint($generated_constraint);
234 return $self->$compile_type_constraint;
237 =head2 create_child_type
239 modifier to make sure we get the constraint_generator
241 around 'create_child_type' => sub {
242 my ($create_child_type, $self, %opts) = @_;
243 return $self->$create_child_type(
245 constraint_generator => $self->__infer_constraint_generator,
255 Override the base class behavior.
260 my ( $self, $type_or_name ) = @_;
261 my $other = Moose::Util::TypeConstraints::find_type_constraint($type_or_name);
263 return unless $other->isa(__PACKAGE__);
266 $self->type_constraints_equals($other)
268 $self->parent->equals( $other->parent )
272 =head2 type_constraints_equals
274 Checks to see if the internal type contraints are equal.
278 sub type_constraints_equals {
279 my ($self, $other) = @_;
280 my @self_type_constraints = @{$self->type_constraints||[]};
281 my @other_type_constraints = @{$other->type_constraints||[]};
283 ## Incoming ay be either arrayref or hashref, need top compare both
284 while(@self_type_constraints) {
285 my $self_type_constraint = shift @self_type_constraints;
286 my $other_type_constraint = shift @other_type_constraints
287 || return; ## $other needs the same number of children.
289 if( ref $self_type_constraint) {
290 $self_type_constraint->equals($other_type_constraint)
291 || return; ## type constraints obviously need top be equal
293 $self_type_constraint eq $other_type_constraint
294 || return; ## strings should be equal
299 return 1; ##If we get this far, everything is good.
304 Give you a better peek into what's causing the error. For now we stringify the
305 incoming deep value with L<Devel::PartialDump> and pass that on to either your
306 custom error message or the default one. In the future we'll try to provide a
307 more complete stack trace of the actual offending elements
311 around 'get_message' => sub {
312 my ($get_message, $self, $value) = @_;
313 my $new_value = Devel::PartialDump::dump($value);
314 return $self->$get_message($new_value);
319 The following modules or resources may be of interest.
321 L<Moose>, L<Moose::Meta::TypeConstraint>
325 John Napiorkowski, C<< <jjnapiork@cpan.org> >>
327 =head1 COPYRIGHT & LICENSE
329 This program is free software; you can redistribute it and/or modify
330 it under the same terms as Perl itself.
334 __PACKAGE__->meta->make_immutable;