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',
35 check_dependent=>'check',
36 get_message_dependent=>'get_message',
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',
52 check_constraining=>'check',
56 =head2 comparison_callback
58 This is a callback which returns a boolean value. It get's passed the value
59 L</constraining_type_constraint> validates as well as the check value.
61 This callback is executed in addition to anything you put into a 'where' clause.
62 However, the 'where' clause only get's the check value.
64 Exercise some sanity, this should be limited to actual comparision operations,
65 not as a sneaky way to mess with the constraining value.
67 This should return a Bool, suitable for ->check (That is true for valid, false
72 has 'comparison_callback' => (
75 predicate=>'has_comparison_callback',
78 =head2 constraint_generator
80 A subref or closure that contains the way we validate incoming values against
81 a set of type constraints.
85 has 'constraint_generator' => (
88 predicate=>'has_constraint_generator',
94 This class defines the following methods.
102 around 'new' => sub {
103 my ($new, $class, @args) = @_;
104 my $self = $class->$new(@args);
105 $self->coercion(MooseX::Meta::TypeCoercion::Dependent->new(
106 type_constraint => $self,
113 We intercept validate in order to custom process the message
118 around 'check' => sub {
119 my ($check, $self, @args) = @_;
120 my ($result, $message) = $self->_compiled_type_constraint->(@args);
125 around 'validate' => sub {
126 my ($validate, $self, @args) = @_;
127 my ($result, $message) = $self->_compiled_type_constraint->(@args);
132 if(defined $message) {
133 return "Inner: $message";
134 } else { warn '......................';
135 return $self->get_message(@args);
140 =head2 generate_constraint_for ($type_constraints)
142 Given some type constraints, use them to generate validation rules for an ref
143 of values (to be passed at check time)
147 sub generate_constraint_for {
148 my ($self, $callback) = @_;
150 my $dependent_pair = shift @_;
151 my ($dependent, $constraining) = @$dependent_pair;
153 ## First need to test the bits
154 unless($self->check_dependent($dependent)) {
155 return (undef, 'bbbbbb');
158 unless($self->check_constraining($constraining)) {
162 my $constraint_generator = $self->constraint_generator;
163 return $constraint_generator->(
171 =head2 parameterize ($dependent, $callback, $constraining)
173 Given a ref of type constraints, create a structured type.
178 my ($self, $dependent_tc, $callback, $constraining_tc) = @_;
179 my $class = ref $self;
180 my $name = $self->_generate_subtype_name($dependent_tc, $callback, $constraining_tc);
181 my $constraint_generator = $self->__infer_constraint_generator;
186 dependent_type_constraint=>$dependent_tc,
187 comparison_callback=>$callback,
188 constraint_generator => $constraint_generator,
189 constraining_type_constraint => $constraining_tc,
193 =head2 _generate_subtype_name
195 Returns a name for the dependent type that should be unique
199 sub _generate_subtype_name {
200 my ($self, $dependent_tc, $callback, $constraining_tc) = @_;
202 "%s_depends_on_%s_via_%s",
203 $dependent_tc, $constraining_tc, $callback,
207 =head2 __infer_constraint_generator
209 This returns a CODEREF which generates a suitable constraint generator. Not
210 user servicable, you'll never call this directly.
212 TBD, this is definitely going to need some work.
216 sub __infer_constraint_generator {
218 if($self->has_constraint_generator) {
219 return $self->constraint_generator;
221 warn "I'm doing the questioning infer generator thing";
223 ## I'm not sure about this stuff but everything seems to work
227 $self->comparison_callback,
228 $self->constraining_type_constraint,
231 $self->constraint->($merged_tc, @_);
236 =head2 compile_type_constraint
238 hook into compile_type_constraint so we can set the correct validation rules.
242 around 'compile_type_constraint' => sub {
243 my ($compile_type_constraint, $self) = @_;
245 if($self->has_comparison_callback &&
246 $self->has_constraining_type_constraint) {
247 my $generated_constraint = $self->generate_constraint_for(
248 $self->comparison_callback,
250 $self->_set_constraint($generated_constraint);
253 return $self->$compile_type_constraint;
256 =head2 create_child_type
258 modifier to make sure we get the constraint_generator
262 around 'create_child_type' => sub {
263 my ($create_child_type, $self, %opts) = @_;
264 return $self->$create_child_type(
266 constraint_generator => $self->__infer_constraint_generator,
276 Override the base class behavior.
281 my ( $self, $type_or_name ) = @_;
282 my $other = Moose::Util::TypeConstraints::find_type_constraint($type_or_name);
284 return unless $other->isa(__PACKAGE__);
287 $self->type_constraints_equals($other)
289 $self->parent->equals( $other->parent )
293 =head2 type_constraints_equals
295 Checks to see if the internal type contraints are equal.
299 sub type_constraints_equals {
300 my ($self, $other) = @_;
301 my @self_type_constraints = @{$self->type_constraints||[]};
302 my @other_type_constraints = @{$other->type_constraints||[]};
304 ## Incoming ay be either arrayref or hashref, need top compare both
305 while(@self_type_constraints) {
306 my $self_type_constraint = shift @self_type_constraints;
307 my $other_type_constraint = shift @other_type_constraints
308 || return; ## $other needs the same number of children.
310 if( ref $self_type_constraint) {
311 $self_type_constraint->equals($other_type_constraint)
312 || return; ## type constraints obviously need top be equal
314 $self_type_constraint eq $other_type_constraint
315 || return; ## strings should be equal
320 return 1; ##If we get this far, everything is good.
325 Give you a better peek into what's causing the error. For now we stringify the
326 incoming deep value with L<Devel::PartialDump> and pass that on to either your
327 custom error message or the default one. In the future we'll try to provide a
328 more complete stack trace of the actual offending elements
332 around 'get_message' => sub {
333 my ($get_message, $self, $value) = @_;
334 my $new_value = Devel::PartialDump::dump($value);
335 return $self->$get_message($new_value);
340 The following modules or resources may be of interest.
342 L<Moose>, L<Moose::Meta::TypeConstraint>
346 John Napiorkowski, C<< <jjnapiork@cpan.org> >>
348 =head1 COPYRIGHT & LICENSE
350 This program is free software; you can redistribute it and/or modify
351 it under the same terms as Perl itself.
355 __PACKAGE__->meta->make_immutable;