package MooseX::Types::Structured;
use 5.008;
+
use Moose::Util::TypeConstraints;
use MooseX::Meta::TypeConstraint::Structured;
+use MooseX::Types::Structured::OverflowHandler;
use MooseX::Types -declare => [qw(Dict Tuple Optional)];
+use Sub::Exporter -setup => { exports => [ qw(Dict Tuple Optional slurpy) ] };
+use Devel::PartialDump;
+use Scalar::Util qw(blessed);
-our $VERSION = '0.06';
+our $VERSION = '0.19';
our $AUTHORITY = 'cpan:JJNAPIORK';
=head1 NAME
The following is example usage for this module.
package Person;
-
+
use Moose;
use MooseX::Types::Moose qw(Str Int HashRef);
use MooseX::Types::Structured qw(Dict Tuple Optional);
middle => Optional[Str],
],
);
-
+
## description is a string field followed by a HashRef of tagged data.
has description => (
isa=>Tuple[
],
);
+ ## Remainder of your class attributes and methods
+
Then you can instantiate this class with something like:
my $john = Person->new(
## Value for 'name' not a HashRef
Person->new( name => 'John' );
-
+
## Value for 'name' has incorrect hash key and missing required keys
Person->new( name => {
first_name => 'John'
});
-
+
## Also incorrect keys
Person->new( name => {
first_name => 'John',
age => 39,
});
-
+
## key 'middle' incorrect type, should be a Str not a ArrayRef
Person->new( name => {
first => 'Vanessa',
middle => [1,2],
last => 'Li',
- });
+ });
And these would cause a constraint error for the 'description' attribute:
## Should be an ArrayRef
Person->new( description => 'Hello I am a String' );
-
+
## First element must be a string not a HashRef.
Person->new (description => [{
tag1 => 'value1',
TypeConstraint[@TypeParameters or %TypeParameters]
-Where 'TypeParameters' is an array or hash of L<Moose::Meta::TypeConstraint>.
+Where 'TypeParameters' is an array reference or hash references of
+L<Moose::Meta::TypeConstraint> objects.
This type library enables structured type constraints. It is built on top of the
L<MooseX::Types> library system, so you should review the documentation for that
you could define a parameterized constraint like:
subtype ArrayOfInts,
- as Arrayref[Int];
+ as ArrayRef[Int];
-which would constraint a value to something like [1,2,3,...] and so on. On the
+which would constrain 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
'internal' type parameter constraints. For the example:
subtype StringFollowedByInt,
as Tuple[Str,Int];
-
-would constrain it's value to something like ['hello', 111] but ['hello', 'world']
+
+would constrain it's value to things like ['hello', 111] but ['hello', 'world']
would fail, as well as ['hello', 111, 'world'] and so on. Here's another
example:
+ package MyApp::Types;
+
+ use MooseX::Types -declare [qw(StringIntOptionalHashRef)];
+ use MooseX::Types::Moose qw(Str Int);
+ use MooseX::Types::Structured qw(Tuple Optional);
+
subtype StringIntOptionalHashRef,
as Tuple[
Str, Int,
Optional[HashRef]
];
-
+
This defines a type constraint that validates values like:
['Hello', 100, {key1 => 'value1', key2 => 'value2'}];
['World', 200];
-
+
Notice that the last type constraint in the structure is optional. This is
enabled via the helper Optional type constraint, which is a variation of the
core Moose type constraint 'Maybe'. The main difference is that Optional type
-constraints are required to validate if they exist, while Maybe permits undefined
-values. So the following example would not validate:
+constraints are required to validate if they exist, while 'Maybe' permits
+undefined values. So the following example would not validate:
StringIntOptionalHashRef->validate(['Hello Undefined', 1000, undef]);
-
+
Please note the subtle difference between undefined and null. If you wish to
allow both null and undefined, you should use the core Moose 'Maybe' type
constraint instead:
- use MooseX::Types -declare [qw(StringIntOptionalHashRef)];
- use MooseX::Types::Moose qw(Maybe);
+ package MyApp::Types;
+
+ use MooseX::Types -declare [qw(StringIntMaybeHashRef)];
+ use MooseX::Types::Moose qw(Str Int Maybe);
use MooseX::Types::Structured qw(Tuple);
- subtype StringIntOptionalHashRef,
+ subtype StringIntMaybeHashRef,
as Tuple[
Str, Int, Maybe[HashRef]
];
This would validate the following:
['Hello', 100, {key1 => 'value1', key2 => 'value2'}];
- ['World', 200, undef];
+ ['World', 200, undef];
['World', 200];
-Structured Constraints are not limited to arrays. You can define a structure
-against a hashref with 'Dict' as in this example:
+Structured constraints are not limited to arrays. You can define a structure
+against a HashRef with the 'Dict' type constaint as in this example:
subtype FirstNameLastName,
as Dict[
lastname => Str,
];
-This would constrain a HashRef to something like:
+This would constrain a HashRef that validates something like:
+
+ {firstname => 'Christopher', lastname => 'Parsons'};
- {firstname => 'Christopher', lastname= > 'Parsons'};
-
but all the following would fail validation:
## Incorrect keys
{first => 'Christopher', last => 'Parsons'};
-
+
## Too many keys
{firstname => 'Christopher', lastname => 'Parsons', middlename => 'Allen'};
-
+
## Not a HashRef
- ['Christopher', 'Christopher'];
+ ['Christopher', 'Parsons'];
These structures can be as simple or elaborate as you wish. You can even
combine various structured, parameterized and simple constraints all together:
- subtype crazy,
+ subtype Crazy,
as Tuple[
Int,
Dict[name=>Str, age=>Int],
ArrayRef[Int]
];
-
-Which would match "[1, {name=>'John', age=>25},[10,11,12]]". Please notice how
-the type parameters can be visually arranged to your liking and to improve the
-clarity of your meaning. You don't need to run then altogether onto a single
-line.
+
+Which would match:
+
+ [1, {name=>'John', age=>25},[10,11,12]];
+
+Please notice how the type parameters can be visually arranged to your liking
+and to improve the clarity of your meaning. You don't need to run then
+altogether onto a single line. Additionally, since the 'Dict' type constraint
+defines a hash constraint, the key order is not meaningful. For example:
+
+ subtype AnyKeyOrder,
+ as Dict[
+ key1=>Int,
+ key2=>Str,
+ key3=>Int,
+ ];
+
+Would validate both:
+
+ {key1 => 1, key2 => "Hi!", key3 => 2};
+ {key2 => "Hi!", key1 => 100, key3 => 300};
+
+As you would expect, since underneath its just a plain old Perl hash at work.
=head2 Alternatives
package MyApp::MyStruct;
use Moose;
-
+
## lazy way to make a bunch of attributes
has $_ for qw(full_name age_in_years);
-
+
package MyApp::MyClass;
use Moose;
-
- has person => (isa => 'MyApp::MyStruct');
-
+
+ has person => (isa => 'MyApp::MyStruct');
+
my $instance = MyApp::MyClass->new(
person=>MyApp::MyStruct->new(
full_name => 'John',
- age_in_years => 39
+ age_in_years => 39,
),
);
-
+
This method may take some additional time to setup but will give you more
flexibility. However, structured constraints are highly compatible with this
method, granting some interesting possibilities for coercion. Try:
package MyApp::MyClass;
-
+
use Moose;
use MyApp::MyStruct;
-
+
## It's recommended your type declarations live in a separate class in order
## to promote reusability and clarity. Inlined here for brevity.
-
+
use MooseX::Types::DateTime qw(DateTime);
use MooseX::Types -declare [qw(MyStruct)];
use MooseX::Types::Moose qw(Str Int);
## Just a shorter version really.
subtype MyStruct,
as 'MyApp::MyStruct';
-
+
## Add the coercions.
coerce MyStruct,
from Dict[
], via {
my $name = $_->{firstname} .' '. $_->{lastname};
my $age = DateTime->now - $_->{dob};
-
+
MyApp::MyStruct->new(
full_name=>$name,
age_in_years=>$age->years,
);
};
-
- has person => (isa=>MyStruct);
-
+
+ has person => (isa=>MyStruct);
+
This would allow you to instantiate with something like:
my $obj = MyApp::MyClass->new( person => {
full_name=>'John Napiorkowski',
age_in_years=>39,
});
-
+
Or even:
my $obj = MyApp::MyClass->new( person => {
subtype Person,
as Dict[name => Str];
-
+
subtype FriendlyPerson,
as Person[
name => Str,
total_friends => Int,
];
-
+
This will actually work BUT you have to take care that the subtype has a
structure that does not contradict the structure of it's parent. For now the
above works, but I will clarify the syntax for this at a future point, so
name => Str,
age => Int
];
-
+
subtype Fullname,
as Dict[
first => Str,
last => Str
];
-
+
coerce Person,
## Coerce an object of a particular class
from BlessedPersonObject, via {
age=>$_->age,
};
},
-
+
## Coerce from [$name, $age]
from ArrayRef, via {
+{
age =>$age->years
}
};
-
+
And that should just work as expected. However, if there are any 'inner'
coercions, such as a coercion on 'Fullname' or on 'DateTime', that coercion
won't currently get activated.
extending coercions to support this welcome on the Moose development channel or
mailing list.
+=head2 Recursion
+
+Newer versions of L<MooseX::Types> support recursive type constraints. That is
+you can include a type constraint as a contained type constraint of itself. For
+example:
+
+ subtype Person,
+ as Dict[
+ name=>Str,
+ friends=>Optional[
+ ArrayRef[Person]
+ ],
+ ];
+
+This would declare a Person subtype that contains a name and an optional
+ArrayRef of Persons who are friends as in:
+
+ {
+ name => 'Mike',
+ friends => [
+ { name => 'John' },
+ { name => 'Vincent' },
+ {
+ name => 'Tracey',
+ friends => [
+ { name => 'Stephenie' },
+ { name => 'Ilya' },
+ ],
+ },
+ ],
+ };
+
+Please take care to make sure the recursion node is either Optional, or declare
+a Union with an non recursive option such as:
+
+ subtype Value
+ as Tuple[
+ Str,
+ Str|Tuple,
+ ];
+
+Which validates:
+
+ [
+ 'Hello', [
+ 'World', [
+ 'Is', [
+ 'Getting',
+ 'Old',
+ ],
+ ],
+ ],
+ ];
+
+Otherwise you will define a subtype thatis impossible to validate since it is
+infinitely recursive. For more information about defining recursive types,
+please see the documentation in L<MooseX::Types> and the test cases.
+
=head1 TYPE CONSTRAINTS
This type library defines the following constraints.
list of contained constraints. For example:
Tuple[Int,Str]; ## Validates [1,'hello']
- Tuple[Str|Object, Int]; ##Validates ['hello', 1] or [$object, 2]
+ Tuple[Str|Object, Int]; ## Validates ['hello', 1] or [$object, 2]
+
+The Values of @constraints should ideally be L<MooseX::Types> declared type
+constraints. We do support 'old style' L<Moose> string based constraints to a
+limited degree but these string type constraints are considered deprecated.
+There will be limited support for bugs resulting from mixing string and
+L<MooseX::Types> in your structures. If you encounter such a bug and really
+need it fixed, we will required a detailed test case at the minimum.
=head2 Dict[%constraints]
Dict[name=>Str, age=>Int]; ## Validates {name=>'John', age=>39}
+The keys in %constraints follow the same rules as @constraints in the above
+section.
+
=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
+this allows is 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
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
{first=>'John', middle=>'James', last=>'Napiorkowski'}
{first=>'Vanessa', last=>'Li'}
-
+
+If you use the 'Maybe' type constraint instead, your values will also validate
+against 'undef', which may be incorrect for you.
+
+=head1 EXPORTABLE SUBROUTINES
+
+This type library makes available for export the following subroutines
+
+=head2 slurpy
+
+Structured type constraints by their nature are closed; that is validation will
+depend on an exact match between your structure definition and the arguments to
+be checked. Sometimes you might wish for a slightly looser amount of validation.
+For example, you may wish to validate the first 3 elements of an array reference
+and allow for an arbitrary number of additional elements. At first thought you
+might think you could do it this way:
+
+ # I want to validate stuff like: [1,"hello", $obj, 2,3,4,5,6,...]
+ subtype AllowTailingArgs,
+ as Tuple[
+ Int,
+ Str,
+ Object,
+ ArrayRef[Int],
+ ];
+
+However what this will actually validate are structures like this:
+
+ [10,"Hello", $obj, [11,12,13,...] ]; # Notice element 4 is an ArrayRef
+
+In order to allow structured validation of, "and then some", arguments, you can
+use the L</slurpy> method against a type constraint. For example:
+
+ use MooseX::Types::Structured qw(Tuple slurpy);
+
+ subtype AllowTailingArgs,
+ as Tuple[
+ Int,
+ Str,
+ Object,
+ slurpy ArrayRef[Int],
+ ];
+
+This will now work as expected, validating ArrayRef structures such as:
+
+ [1,"hello", $obj, 2,3,4,5,6,...]
+
+A few caveats apply. First, the slurpy type constraint must be the last one in
+the list of type constraint parameters. Second, the parent type of the slurpy
+type constraint must match that of the containing type constraint. That means
+that a Tuple can allow a slurpy ArrayRef (or children of ArrayRefs, including
+another Tuple) and a Dict can allow a slurpy HashRef (or children/subtypes of
+HashRef, also including other Dict constraints).
+
+Please note the the technical way this works 'under the hood' is that the
+slurpy keyword transforms the target type constraint into a coderef. Please do
+not try to create your own custom coderefs; always use the slurpy method. The
+underlying technology may change in the future but the slurpy keyword will be
+supported.
+
+=head1 ERROR MESSAGES
+
+Error reporting has been improved to return more useful debugging messages. Now
+I will stringify the incoming check value with L<Devel::PartialDump> so that you
+can see the actual structure that is tripping up validation. Also, I report the
+'internal' validation error, so that if a particular element inside the
+Structured Type is failing validation, you will see that. There's a limit to
+how deep this internal reporting goes, but you shouldn't see any of the "failed
+with ARRAY(XXXXXX)" that we got with earlier versions of this module.
+
+This support is continuing to expand, so it's best to use these messages for
+debugging purposes and not for creating messages that 'escape into the wild'
+such as error messages sent to the user.
+
+Please see the test '12-error.t' for a more lengthy example. Your thoughts and
+preferable tests or code patches very welcome!
+
=head1 EXAMPLES
Here are some additional example usage for structured types. All examples can
other MooseX::Types libraries.
package Test::MooseX::Meta::TypeConstraint::Structured::Examples::Normalize;
-
+
use Moose;
use DateTime;
-
+
use MooseX::Types::Structured qw(Dict Tuple);
use MooseX::Types::DateTime qw(DateTime);
use MooseX::Types::Moose qw(Int Str Object);
use MooseX::Types -declare => [qw(Name Age Person)];
-
+
subtype Person,
- as Dict[name=>Str, age=>Int];
-
+ as Dict[
+ name=>Str,
+ age=>Int,
+ ];
+
coerce Person,
- from Dict[first=>Str, last=>Str, years=>Int],
- via { +{
+ from Dict[
+ first=>Str,
+ last=>Str,
+ years=>Int,
+ ], via { +{
name => "$_->{first} $_->{last}",
- age=>$_->{years},
+ age => $_->{years},
}},
- from Dict[fullname=>Dict[last=>Str, first=>Str], dob=>DateTime],
+ from Dict[
+ fullname=>Dict[
+ last=>Str,
+ first=>Str,
+ ],
+ dob=>DateTime,
+ ],
## DateTime needs to be inside of single quotes here to disambiguate the
## class package from the DataTime type constraint imported via the
## line "use MooseX::Types::DateTime qw(DateTime);"
name => "$_->{fullname}{first} $_->{fullname}{last}",
age => ($_->{dob} - 'DateTime'->now)->years,
}};
-
+
has person => (is=>'rw', isa=>Person, coerce=>1);
-
+
And now you can instantiate with all the following:
__PACKAGE__->new(
- name=>'John Napiorkowski',
- age=>39,
+ person=>{
+ name=>'John Napiorkowski',
+ age=>39,
+ },
);
-
+
__PACKAGE__->new(
- first=>'John',
- last=>'Napiorkowski',
- years=>39,
+ person=>{
+ first=>'John',
+ last=>'Napiorkowski',
+ years=>39,
+ },
);
-
+
__PACKAGE__->new(
- fullname => {
- first=>'John',
- last=>'Napiorkowski'
+ person=>{
+ fullname => {
+ first=>'John',
+ last=>'Napiorkowski'
+ },
+ dob => 'DateTime'->new(
+ year=>1969,
+ month=>2,
+ day=>13
+ ),
},
- dob => 'DateTime'->new(
- year=>1969,
- month=>2,
- day=>13
- ),
);
-
+
This technique is a way to support various ways to instantiate your class in a
clean and declarative way.
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, $values) = @_;
my @type_constraints = defined $type_constraints ?
- @$type_constraints : ();
+ @$type_constraints : ();
+
+ my $overflow_handler;
+ if($type_constraints[-1] && blessed $type_constraints[-1]
+ && $type_constraints[-1]->isa('MooseX::Types::Structured::OverflowHandler')) {
+ $overflow_handler = pop @type_constraints;
+ }
+
my @values = defined $values ? @$values: ();
## Perform the checking
while(@type_constraints) {
if(@values) {
my $value = shift @values;
unless($type_constraint->check($value)) {
+ $_[2]->{message} = $type_constraint->get_message($value)
+ if ref $_[2];
return;
- }
+ }
} else {
## Test if the TC supports null values
unless($type_constraint->check()) {
+ $_[2]->{message} = $type_constraint->get_message('NULL')
+ if ref $_[2];
return;
}
}
}
## Make sure there are no leftovers.
if(@values) {
- return;
+ if($overflow_handler) {
+ return $overflow_handler->check([@values], $_[2]);
+ } else {
+ $_[2]->{message} = "More values than Type Constraints!"
+ if ref $_[2];
+ return;
+ }
} elsif(@type_constraints) {
+ $_[2]->{message} =
+ "Not enough values for all defined type constraints. Remaining: ". join(', ',@type_constraints)
+ if ref $_[2];
return;
} else {
return 1;
}
)
);
-
+
Moose::Util::TypeConstraints::get_type_constraint_registry->add_type_constraint(
MooseX::Meta::TypeConstraint::Structured->new(
name => "MooseX::Types::Structured::Dict",
parent => find_type_constraint('HashRef'),
- constraint_generator=> sub {
+ constraint_generator=> sub {
## Get the constraints and values to check
my ($type_constraints, $values) = @_;
- my %type_constraints = defined $type_constraints ?
- @$type_constraints : ();
+ my @type_constraints = defined $type_constraints ?
+ @$type_constraints : ();
+
+ my $overflow_handler;
+ if($type_constraints[-1] && blessed $type_constraints[-1]
+ && $type_constraints[-1]->isa('MooseX::Types::Structured::OverflowHandler')) {
+ $overflow_handler = pop @type_constraints;
+ }
+ my (%type_constraints) = @type_constraints;
my %values = defined $values ? %$values: ();
## Perform the checking
while(%type_constraints) {
my $value = $values{$key};
delete $values{$key};
unless($type_constraint->check($value)) {
+ $_[2]->{message} = $type_constraint->get_message($value)
+ if ref $_[2];
return;
}
} else {
## Test to see if the TC supports null values
unless($type_constraint->check()) {
+ $_[2]->{message} = $type_constraint->get_message('NULL')
+ if ref $_[2];
return;
}
}
}
## Make sure there are no leftovers.
- if(%values) {
- return;
+ if(%values) {
+ if($overflow_handler) {
+ return $overflow_handler->check(+{%values});
+ } else {
+ $_[2]->{message} = "More values than Type Constraints!"
+ if ref $_[2];
+ return;
+ }
} elsif(%type_constraints) {
+ $_[2]->{message} =
+ "Not enough values for all defined type constraints. Remaining: ". join(', ',values %values)
+ if ref $_[2];
return;
} else {
return 1;
Moose::Util::TypeConstraints::add_parameterizable_type($Optional);
}
+sub slurpy ($) {
+ my ($tc) = @_;
+ return MooseX::Types::Structured::OverflowHandler->new(
+ type_constraint => $tc,
+ );
+}
=head1 SEE ALSO
=head1 TODO
-Need to clarify deep coercions, need to clarify subtypes of subtypes. Would
-like more and better examples and probably some best practices guidence.
+Here's a list of stuff I would be happy to get volunteers helping with:
+
+ * All POD examples need test cases in t/documentation/*.t
+ * Want to break out the examples section to a separate cookbook style POD.
+ * Want more examples and best practice / usage guidance for authors
+ * Need to clarify deep coercions,
=head1 AUTHOR
-John Napiorkowski, C<< <jjnapiork@cpan.org> >>
+John Napiorkowski <jjnapiork@cpan.org>
+
+=head1 CONTRIBUTORS
+
+The following people have contributed to this module and agree with the listed
+Copyright & license information included below:
+
+ Florian Ragwitz, <rafl@debian.org>
+ Yuval Kogman, <nothingmuch@woobling.org>
+ Tomas Doran, <bobtfish@bobtfish.net>
=head1 COPYRIGHT & LICENSE
-This program is free software; you can redistribute it and/or modify
-it under the same terms as Perl itself.
+Copyright 2008-2009, John Napiorkowski <jjnapiork@cpan.org>
+
+This program is free software; you can redistribute it and/or modify it under
+the same terms as Perl itself.
=cut
-
+
1;
projects / gitmo/MooseX-Types-Structured.git / blobdiff