package MooseX::Types::Structured;
+use 5.008;
use Moose;
use Moose::Util::TypeConstraints;
use MooseX::Meta::TypeConstraint::Structured;
-use MooseX::Types -declare => [qw(Dict Tuple)];
+use MooseX::Types -declare => [qw(Dict Tuple Optional)];
-our $VERSION = '0.03';
+our $VERSION = '0.06';
our $AUTHORITY = 'cpan:JJNAPIORK';
=head1 NAME
use Moose;
use MooseX::Types::Moose qw(Str Int);
- use MooseX::Types::Structured qw(Dict Tuple);
-
- has name => (isa=>Dict[first_name=>Str, last_name=>Str]);
+ use MooseX::Types::Structured qw(Dict Optional);
+
+ ## A name has a first and last part, but middle names are not required
+ has name => (
+ isa=>Dict[
+ first=>Str,
+ last=>Str,
+ middle=>Optional[Str],
+ ],
+ );
Then you can instantiate this class with something like:
- my $instance = MyApp::MyClass->new(
- name=>{first_name=>'John', last_name=>'Napiorkowski'},
- );
-
-But all of these would cause an error:
+ my $john = MyApp::MyClass->new(
+ name => {
+ first=>'John',
+ middle=>'James'
+ last=>'Napiorkowski',
+ },
+ );
+
+ my $vanessa = MyApp::MyClass->new(
+ name => {
+ first=>'Vanessa',
+ last=>'Li'
+ },
+ );
- my $instance = MyApp::MyClass->new(name=>'John');
- my $instance = MyApp::MyClass->new(name=>{first_name=>'John'});
- my $instance = MyApp::MyClass->new(name=>{first_name=>'John', age=>39});
+But all of these would cause a constraint error for the 'name' attribute:
+ MyApp::MyClass->new( name=>'John' );
+ MyApp::MyClass->new( name=>{first_name=>'John'} );
+ MyApp::MyClass->new( name=>{first_name=>'John', age=>39} );
+ MyApp::MyClass->new( name=>{first=>'Vanessa', middle=>[1,2], last=>'Li'} );
+
Please see the test cases for more examples.
=head1 DESCRIPTION
TypeConstraint[TypeParameters]
-Where TypeParameters is a list of type constraints.
+Where 'TypeParameters' is an array or hash of L</Moose::Meta::TypeConstraint>
+type constraints.
This type library enables structured type constraints. It is build on top of the
L<MooseX::Types> library system, so you should review the documentation for that
if you are not familiar with it.
-=head Comparing Parameterized types to Structured types
+=head2 Comparing Parameterized types to Structured types
Parameterized constraints are built into the core Moose types 'HashRef' and
'ArrayRef'. Structured types have similar functionality, so their syntax is
likewise similar. For example, you could define a parameterized constraint like:
- subtype HashOfInts,
- as Hashref[Int];
+ subtype ArrayOfInts,
+ as Arrayref[Int];
which would constraint a value to something like [1,2,3,...] and so on. On the
other hand, a structured type constraint explicitly names all it's allowed type
as Tuple[Str,Int];
would constrain it's value to something like ['hello', 111] but ['hello', 'world']
-would fail, as well as ['hello', 111, 'world']
+would fail, as well as ['hello', 111, 'world'] and so on.
+
+Structured Constraints are not limited to arrays. You can define a structure
+against a hashref with 'Dict' as in this example:
+
+ subtype FirstNameLastName,
+ as Dict[firste=>Str, lastname=>Str];
+
+This would constrain a hashref to something like:
+
+ {firstname=>'Vanessa', lastname=>'Li'};
+
+but all the following would fail validation:
+
+ {first=>'Vanessa', last=>'Li'};
+ {firstname=>'Vanessa', lastname=>'Li', middlename=>'NA'};
+ ['Vanessa', 'Li'];
These structures can be as simple or elaborate as you wish. You can even
combine various structured, parameterized and simple constraints all together:
as in this example:
subtype Person,
- as Dict[name=>Str, age=>iIt];
+ as Dict[name=>Str, age=>Int];
subtype FriendlyPerson,
as Person[name=>Str, age=>Int, totalFriends=>Int];
as Dict[first=>Str, last=>Str];
coerce Person,
+ ## Coerce an object of a particular class
from BlessedPersonObject,
via { +{name=>$_->name, age=>$_->age} },
+ ## Coerce from [$name, $age]
from ArrayRef,
via { +{name=>$_->[0], age=>$_->[1] },
+ ## Coerce from {fullname=>{first=>...,last=>...}, dob=>$DateTimeObject}
from Dict[fullname=>Fullname, dob=>DateTime],
via {
my $age = $_->dob - DateTime->now;
Dict[name=>Str, age=>Int]; ## Validates {name=>'John', age=>39}
+=head2 Optional [$constraint]
+
+This is primarily a helper constraint for Dict and Tuple type constraints. What
+this allows if for you to assert that a given type constraint is allowed to be
+null (but NOT undefined). If the value is null, then the type constraint passes
+but if the value is defined it must validate against the type constraint. This
+makes it easy to make a Dict where one or more of the keys doesn't have to exist
+or a tuple where some of the values are not required. For example:
+
+ subtype Name() => as Dict[
+ first=>Str,
+ last=>Str,
+ middle=>Optional[Str],
+ ];
+
+Creates a constraint that validates against a hashref with the keys 'first' and
+'last' being strings and required while an optional key 'middle' is must be a
+string if it appears but doesn't have to appear. So in this case both the
+following are valid:
+
+ {first=>'John', middle=>'James', last=>'Napiorkowski'}
+ {first=>'Vanessa', last=>'Li'}
+
=head1 EXAMPLES
Here are some additional example usage for structured types. All examples can
MooseX::Meta::TypeConstraint::Structured->new(
name => "MooseX::Types::Structured::Tuple" ,
parent => find_type_constraint('ArrayRef'),
- constraint_generator=> sub {
+ constraint_generator=> sub {
## Get the constraints and values to check
- my @type_constraints = @{shift @_};
- my @values = @{shift @_};
+ my ($type_constraints, $values) = @_;
+ my @type_constraints = defined $type_constraints ? @$type_constraints: ();
+ my @values = defined $values ? @$values: ();
## Perform the checking
while(@type_constraints) {
my $type_constraint = shift @type_constraints;
return;
}
} else {
- return;
+ unless($type_constraint->check()) {
+ return;
+ }
}
}
## Make sure there are no leftovers.
MooseX::Meta::TypeConstraint::Structured->new(
name => "MooseX::Types::Structured::Dict",
parent => find_type_constraint('HashRef'),
- constraint_generator=> sub {
+ constraint_generator=> sub {
## Get the constraints and values to check
- my %type_constraints = @{shift @_};
- my %values = %{shift @_};
+ my ($type_constraints, $values) = @_;
+ my %type_constraints = defined $type_constraints ? @$type_constraints: ();
+ my %values = defined $values ? %$values: ();
## Perform the checking
while(%type_constraints) {
my($key, $type_constraint) = each %type_constraints;
unless($type_constraint->check($value)) {
return;
}
- } else {
- return;
+ } else {
+ unless($type_constraint->check()) {
+ return;
+ }
}
}
## Make sure there are no leftovers.
- if(%values) {
+ if(%values) {
return;
} elsif(%type_constraints) {
return;
)
);
+OPTIONAL: {
+ my $Optional = Moose::Meta::TypeConstraint::Parameterizable->new(
+ name => 'MooseX::Types::Structured::Optional',
+ package_defined_in => __PACKAGE__,
+ parent => find_type_constraint('Item'),
+ constraint => sub { 1 },
+ constraint_generator => sub {
+ my ($type_parameter, @args) = @_;
+ my $check = $type_parameter->_compiled_type_constraint();
+ return sub {
+ my (@args) = @_;
+ if(exists($args[0])) {
+ ## If it exists, we need to validate it
+ $check->($args[0]);
+ } else {
+ ## But it's is okay if the value doesn't exists
+ return 1;
+ }
+ }
+ }
+ );
+
+ Moose::Util::TypeConstraints::register_type_constraint($Optional);
+ Moose::Util::TypeConstraints::add_parameterizable_type($Optional);
+}
+
+
=head1 SEE ALSO
The following modules or resources may be of interest.
projects / gitmo/MooseX-Types-Structured.git / blobdiff