NAME
MooseX::Params::Validate - an extension of Params::Validate using
Moose's types
VERSION
version 0.21
SYNOPSIS
package Foo;
use Moose;
use MooseX::Params::Validate;
sub foo {
my ( $self, %params ) = validated_hash(
\@_,
bar => { isa => 'Str', default => 'Moose' },
);
return "Hooray for $params{bar}!";
}
sub bar {
my $self = shift;
my ( $foo, $baz, $gorch ) = validated_list(
\@_,
foo => { isa => 'Foo' },
baz => { isa => 'ArrayRef | HashRef', optional => 1 },
gorch => { isa => 'ArrayRef[Int]', optional => 1 }
);
[ $foo, $baz, $gorch ];
}
DESCRIPTION
This module fills a gap in Moose by adding method parameter validation
to Moose. This is just one of many developing options, it should not be
considered the "official" one by any means though.
You might also want to explore MooseX::Method::Signatures and
MooseX::Declare.
CAVEATS
It is not possible to introspect the method parameter specs; they are
created as needed when the method is called and cached for subsequent
calls.
EXPORTS
validated_hash( \@_, %parameter_spec )
This behaves similarly to the standard Params::Validate validate
function and returns the captured values in a HASH. The one exception
is where if it spots an instance in the @_, then it will handle it
appropriately (unlike Params::Validate which forces you to shift you
$self first).
The values in @_ can either be a set of name-value pairs or a single
hash reference.
The %parameter_spec accepts the following options:
isa
The isa option can be either; class name, Moose type constraint
name or an anon Moose type constraint.
does
The does option can be either; role name or an anon Moose type
constraint.
default
This is the default value to be used if the value is not supplied.
optional
As with Params::Validate, all options are considered required
unless otherwise specified. This option is passed directly to
Params::Validate.
coerce
If this is true and the parameter has a type constraint which has
coercions, then the coercion will be called for this parameter. If
the type does have coercions, then this parameter is ignored.
depends
Another parameter that this one depends on. See the
Params::Validate documentation for more details.
This function is also available under its old name, validate.
validated_list( \@_, %parameter_spec )
The %parameter_spec accepts the same options as above, but returns
the parameters as positional values instead of a HASH. This is best
explained by example:
sub foo {
my ( $self, $foo, $bar ) = validated_list(
\@_,
foo => { isa => 'Foo' },
bar => { isa => 'Bar' },
);
$foo->baz($bar);
}
We capture the order in which you defined the parameters and then
return them as a list in the same order. If a param is marked
optional and not included, then it will be set to undef.
The values in @_ can either be a set of name-value pairs or a single
hash reference.
Like validated_hash, if it spots an object instance as the first
parameter of @_, it will handle it appropriately, returning it as the
first argument.
This function is also available under its old name, validatep.
pos_validated_list( \@_, $spec, $spec, ... )
This function validates a list of positional parameters. Each $spec
should validate one of the parameters in the list:
sub foo {
my $self = shift;
my ( $foo, $bar ) = pos_validated_list(
\@_,
{ isa => 'Foo' },
{ isa => 'Bar' },
);
...
}
Unlike the other functions, this function cannot find $self in the
argument list. Make sure to shift it off yourself before doing
validation.
The values in @_ must be a list of values. You cannot pass the values
as an array reference, because this cannot be distinguished from
passing one value which is itself an array reference.
If a parameter is marked as optional and is not present, it will
simply not be returned.
If you want to pass in any of the cache control parameters described
below, simply pass them after the list of parameter validation specs:
sub foo {
my $self = shift;
my ( $foo, $bar ) = pos_validated_list(
\@_,
{ isa => 'Foo' },
{ isa => 'Bar' },
MX_PARAMS_VALIDATE_NO_CACHE => 1,
);
...
}
EXCEPTION FOR FAILED VALIDATION
If a type constraint check for a parameter fails, then the error is
thrown as a
MooseX::Params::Validate::Exception::ValidationFailedForTypeConstraint
object. When stringified, this object will use the error message
generated by the type constraint that failed.
Other errors are simply percolated up from Params::Validate as-is, and
are not turned into exception objects. This may change in the future
(or more likely, Params::Validate may start throwing objects of its
own).
ALLOWING EXTRA PARAMETERS
By default, any parameters not mentioned in the parameter spec cause
this module to throw an error. However, you can have this module simply
ignore them by setting MX_PARAMS_VALIDATE_ALLOW_EXTRA to a true value
when calling a validation subroutine.
When calling validated_hash or pos_validated_list the extra parameters
are simply returned in the hash or list as appropriate. However, when
you call validated_list the extra parameters will not be returned at
all. You can get them by looking at the original value of @_.
EXPORTS
By default, this module exports the validated_hash, validated_list, and
pos_validated_list.
If you would prefer to import the now deprecated functions validate and
validatep instead, you can use the :deprecated tag to import them.
IMPORTANT NOTE ON CACHING
When a validation subroutine is called the first time, the parameter
spec is prepared and cached to avoid unnecessary regeneration. It uses
the fully qualified name of the subroutine (package + subname) as the
cache key. In 99.999% of the use cases for this module, that will be
the right thing to do.
However, I have (ab)used this module occasionally to handle dynamic
sets of parameters. In this special use case you can do a couple things
to better control the caching behavior.
* Passing in the MX_PARAMS_VALIDATE_NO_CACHE flag in the parameter
spec this will prevent the parameter spec from being cached.
sub foo {
my ( $self, %params ) = validated_hash(
\@_,
foo => { isa => 'Foo' },
MX_PARAMS_VALIDATE_NO_CACHE => 1,
);
}
* Passing in MX_PARAMS_VALIDATE_CACHE_KEY with a value to be used as
the cache key will bypass the normal cache key generation.
sub foo {
my ( $self, %params ) = validated_hash(
\@_,
foo => { isa => 'Foo' },
MX_PARAMS_VALIDATE_CACHE_KEY => 'foo-42',
);
}
MAINTAINER
Dave Rolsky <autarch@urth.org>
BUGS
Please submit bugs to the CPAN RT system at
http://rt.cpan.org/NoAuth/ReportBug.html?Queue=moosex-params-validate
or via email at bug-moosex-params-validate@rt.cpan.org.
AUTHORS
* Stevan Little <stevan@cpan.org>
* Dave Rolsky <autarch@urth.org>
CONTRIBUTORS
* Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
* Hans Staugaard <h.staugaard@tweakker.com>
* Karen Etheridge <ether@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2013 - 2015 by Stevan Little
<stevan@cpan.org>.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.