Re: "automatically" wrapping methods.

I'd look to moving this logic into a parameterised role, with the parameters being the methods you are looking at validating. Have a look at MooseX::Role::Parameterized for details on how to do this. 

Take care,
Mark. 

On 9 Jan 2012, at 05:14, Bill Moseley <[email protected]> wrote:

> I have have a number of classes that include methods that need input
> validation.  I use a validation class for each method which means
> validation is called the same way every time its used.  That is, I have a
> common pattern I'm using on a number of methods and wondering if anyone can
> suggest a more clever approach so I don't end up repeating similar code.
> 
> A code example might make it clearer:
> 
> package MyModel::User;
> use Moose;
> extends 'MyModel::Base';
> 
> 
> # This method is called by the consumer to create a new user,
> # and the $user_data passed here is assumed to have been validated.
> 
> sub new_user {
>    my ( $self, $user_data ) = @_;
> 
>    return $self->ORM_layer( 'User' )->create( $user_data );
> }
> 
> 
> # Here's the code that gets repeated for every method that requires
> validation.
> 
> around new_user => sub {
>    my ( $orig, $self, $args ) = @_;
> 
>    # Fetch validation instance for
>    my $validation_class = $self->validation_class_for_method( 'new_user' );
>    my $validation_instance = $validation_class->new( $args );
> 
>    # Throw exception object with validation failures unless data passes
> validation.
>    $validation_instance->thow_exception unless
> $validation_instance->validates_ok;
> 
>    return;
> };
> 
> 
> So, I'm looking for a suggestion how to avoid the explicit wrapper.  One
> option I was considering was something Catalyst-like with subroutine
> attributes:
> 
> sub new_user : Validate {
>    ...
> }
> 
> Then all methods with the "Validate" attribute would automatically get
> wrapped, although I'm not clear if that's the best approach or even its
> implementation.
> 
> Thanks,
> 
> 
> 
> 
> 
> -- 
> Bill Moseley
> [email protected]