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MooseX::Params::Validate(3) |
User Contributed Perl Documentation |
MooseX::Params::Validate(3) |
MooseX::Params::Validate - an extension of Params::Validate using Moose's types
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 ];
}
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".
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.
- 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,
);
...
}
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).
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 @_.
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.
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',
);
}
Dave Rolsky <autarch@urth.org>
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.
- Stevan Little <stevan@cpan.org>
- Dave Rolsky <autarch@urth.org>
- Dagfinn Ilmari Mannsåker <ilmari@ilmari.org>
- Hans Staugaard <h.staugaard@tweakker.com>
- Karen Etheridge <ether@cpan.org>
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.
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