Net::Amazon::Request::ASIN - Class for submitting ASIN requests

  use Net::Amazon;
  use Net::Amazon::Request::ASIN;

  my $ua = Net::Amazon->new(
      token       => 'YOUR_AMZN_TOKEN'
  );

  my $req = Net::Amazon::Request::ASIN->new( 
      asin  => '0201360683'
  );

    # Response is of type Net::Amazon::Response::ASIN
  my $resp = $ua->request($req);

######################################################################
package Net::Amazon::Request::ASIN;
######################################################################
use warnings;
use strict;
use base qw(Net::Amazon::Request);

# These values are defined in the AWS SDK
# (http://amazon.com/webservices) under
# "Product and Catalog Data" / "ASIN and ISBN Searches"
use constant MAX_ASINS_PER_REQUEST => 10;


##################################################
sub new {
##################################################
    my($class, %options) = @_;

    $class->_assert_options_defined(\%options, 'asin');

    $class->_convert_option(\%options,
                            'asin',
                            'ItemId',
                            \&_process_asin_option);
    
    my $self = $class->SUPER::new(%options);

    bless $self, $class;   # reconsecrate
}

##
## PRIVATE FUNCTIONS
##

# _process_asin_option( OPTIONS, KEY )
#
# Takes a reference to a hash of OPTIONS and checks the value keyed by
# KEY to make sure it looks legitimate.  If the value associated with
# KEY is an array, we check to make sure that we're not asking for
# too many asins at once.
#
# Returns true if all goes well. If any problems are encountered,
# die() will be called.
#
sub _process_asin_option {
    my ($options, $key) = @_;

    # If the asins are supplied in the form of an array, we have to
    # make sure that the caller isn't trying to ask for too many at a
    # time. If we don't make this test, those excessive asins will be
    # silently ignored by the AWS servers...resulting in potentially
    # confusing results for the user.
    if ( ref $options->{$key} eq 'ARRAY' ) {
        my $max_asins = MAX_ASINS_PER_REQUEST;

        # Dying is the right thing to do here because this is
        # indicative of a programming error.
        die "Only $max_asins may be requested at a time"
            if ( @{$options->{$key}} > $max_asins );

        $options->{$key} = join ',', @{$options->{$key}};
    } elsif ( ref $options->{$key} ) {
        die "The 'asin' parameter must either be a scalar or an array";
    }

    return 1;
}

1;

__END__