NAME

Net::Amazon - Framework for accessing amazon.com via REST

SYNOPSIS

  use Net::Amazon;

  my $ua = Net::Amazon->new(
        associate_tag => 'YOUR_AMZN_ASSOCIATE_TAG',
	token         => 'YOUR_AMZN_TOKEN',
	secret_key    => 'YOUR_AMZN_SECRET_KEY');

    # Get a request object
  my $response = $ua->search(asin => '0201360683');

  if($response->is_success()) {
      print $response->as_string(), "\n";
  } else {
      print "Error: ", $response->message(), "\n";
  }

ABSTRACT

Net::Amazon provides an object-oriented interface to amazon.com's
REST interface. This way it's possible to create applications
using Amazon's vast amount of data via a functional interface, without
having to worry about the underlying communication mechanism.

DESCRIPTION

Net::Amazon works very much like LWP: First you define a useragent like

my $ua = Net::Amazon->new(
    associate_tag => 'YOUR_AMZN_ASSOCIATE_TAG',
    token         => 'YOUR_AMZN_TOKEN',
    secret_key    => 'YOUR_AMZN_SECRET_KEY',
    max_pages     => 3,
);

which you pass your personal amazon developer's token (can be obtained from http://amazon.com/soap) and (optionally) the maximum number of result pages the agent is going to request from Amazon in case all results don't fit on a single page (typically holding 20 items). Note that each new page requires a minimum delay of 1 second to comply with Amazon's one-query-per-second policy.

According to the different search methods on Amazon, there's a bunch of different request types in Net::Amazon. The user agent's convenience method search() triggers different request objects, depending on which parameters you pass to it:

$ua->search(asin => "0201360683")

The asin parameter has Net::Amazon search for an item with the specified ASIN. If the specified value is an arrayref instead of a single scalar, like in

$ua->search(asin => ["0201360683", "0596005083"]) 

then a search for multiple ASINs is performed, returning a list of results.

$ua->search(actor => "Adam Sandler")

The actor parameter has the user agent search for items created by the specified actor. Can return many results.

$ua->search(artist => "Rolling Stones")

The artist parameter has the user agent search for items created by the specified artist. Can return many results.

$ua->search(author => "Robert Jordan")

The author parameter has the user agent search for items created by the specified author. Can return many results.

$ua->search(browsenode=>"4025", mode=>"books" [, keywords=>"perl"])

Returns a list of items by category ID (node). For example node "4025" is the CGI books category. You can add a keywords parameter to filter the results by that keyword.

$ua->search(exchange => 'Y04Y3424291Y2398445')

Returns an item offered by a third-party seller. The item is referenced by the so-called exchange ID.

$ua->search(keyword => "perl xml", mode => "books")

Search by keyword, mandatory parameters keyword and mode. Can return many results.

DETAILS Net::Amazon is based on Amazon Web Services version 4, and uses WSDL version 2011-08-01.

CACHING

Responses returned by Amazon's web service can be cached locally. Net::Amazon's new method accepts a reference to a Cache object. Cache (or one of its companions like Cache::Memory, Cache::File, etc.) can be downloaded from CPAN, please check their documentation for details. In fact, any other type of cache implementation will do as well, see the requirements below.

Here's an example utilizing a file cache which causes Net::Amazon to cache responses for 30 minutes:

use Cache::File;

my $cache = Cache::File->new( 
    cache_root        => '/tmp/mycache',
    default_expires   => '30 min',
);

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

Net::Amazon uses positive caching only, errors won't be cached. Erroneous requests will be sent to Amazon every time. Positive cache entries are keyed by the full URL used internally by requests submitted to Amazon.

Caching isn't limited to the Cache class. Any cache object which adheres to the following interface can be used:

    # Set a cache value
$cache->set($key, $value);

    # Return a cached value, 'undef' if it doesn't exist
$cache->get($key);

COMPRESSION

By default Net::Amazon will attempt to use HTTP compression if the Compress::Zlib module is available. Pass compress => 0 to ->new() to disable this feature.

PROXY SETTINGS

Net::Amazon uses LWP::UserAgent under the hood to send web requests to Amazon's web site. If you're in an environment where all Web traffic goes through a proxy, there's two ways to configure that.

First, Net::Amazon picks up proxy settings from environment variables:

export http_proxy=http://proxy.my.place:8080

in the surrounding shell or setting

$ENV{http_proxy} = "http://proxy.my.place:8080";

in your Perl script will route all requests through the specified proxy.

Secondly, you can pass a user agent instance to Net::Amazon's constructor:

    use Net::Amazon;
    use LWP::UserAgent;

    my $ua = LWP::UserAgent->new();
    my $na = Net::Amazon->new(
	ua            => $ua, 
        associate_tag => 'YOUR_AMZN_ASSOCIATE_TAG',
	token         => 'YOUR_AMZN_TOKEN',
        secret_key    => 'YOUR_AMZN_SECRET_KEY',
    );
    # ...

This way, you can configure $ua up front before Net::Amazon will use it.

DEBUGGING

If something's going wrong and you want more verbosity, just bump up Net::Amazon's logging level. Net::Amazon comes with Log::Log4perl statements embedded, which are disabled by default. However, if you initialize Log::Log4perl, e.g. like

use Net::Amazon;
use Log::Log4perl qw(:easy);

Log::Log4perl->easy_init($DEBUG);
my Net::Amazon->new();
# ...

you'll see what's going on behind the scenes, what URLs the module is requesting from Amazon and so forth. Log::Log4perl allows all kinds of fancy stuff, like writing to a file or enabling verbosity in certain parts only -- check http://log4perl.sourceforge.net for details.

LIVE TESTING

Results returned by Amazon can be incomplete or simply wrong at times, due to their "best effort" design of the service. This is why the test suite that comes with this module has been changed to perform its test cases against canned data. If you want to perform the tests against the live Amazon servers instead, just set the environment variable

NET_AMAZON_LIVE_TESTS=1

WHY ISN'T THERE SUPPORT FOR METHOD XYZ?

Because nobody wrote it yet. If Net::Amazon doesn't yet support a method advertised on Amazon's web service, you could help us out. Net::Amazon has been designed to be expanded over time, usually it only takes a couple of lines to support a new method, the rest is done via inheritance within Net::Amazon.

Here's the basic plot:

• Get Net::Amazon from CVS. Use

      # (Just hit enter when prompted for a password)
  cvs -d:pserver:anonymous@cvs.net-amazon.sourceforge.net:/cvsroot/net-amazon login
  cvs -z3 -d:pserver:anonymous@cvs.net-amazon.sourceforge.net:/cvsroot/net-amazon co Net-Amazon

  If this doesn't work, just use the latest distribution from net-amazon.sourceforge.net.

• Write a new Net::Amazon::Request::XYZ package, start with this template

  ######################################
  package Net::Amazon::Request::XYZ;
  ######################################
  use base qw(Net::Amazon::Request);
  
  ######################################
  sub new {
  ######################################
      my($class, %options) = @_;
  
      if(!exists $options{XYZ_option}) {
          die "Mandatory parameter 'XYZ_option' not defined";
      }
  
      my $self = $class->SUPER::new(%options);
  
      bless $self, $class;   # reconsecrate
  }

  and add documentation. Then, create a new Net::Amazon::Response::XYZ module:

  ##############################
  package Net::Amazon::Response;
  ##############################
  use base qw(Net::Amazon::Response);
  
  use Net::Amazon::Property;
  
  ##############################
  sub new {
  ##############################
      my($class, %options) = @_;
  
      my $self = $class->SUPER::new(%options);
  
      bless $self, $class;   # reconsecrate
  }

  and also add documentation to it. Then, add the line

  use Net::Amazon::Request::XYZ;

  to Net/Amazon.pm.

And that's it! Again, don't forget the add documentation part. Modules without documentation are of no use to anybody but yourself.

Check out the different Net::Amazon::Request::* and Net::Amazon::Response modules in the distribution if you need to adapt your new module to fulfil any special needs, like a different Amazon URL or a different way to handle the as_string() method. Also, post and problems you might encounter to the mailing list, we're gonna help you out.

If possible, provide a test case for your extension. When finished, send a patch to the mailing list at

net-amazon-devel@lists.sourceforge.net

and if it works, I'll accept it and will work it into the main distribution. Your name will show up in the contributor's list below (unless you tell me otherwise).

SAMPLE SCRIPTS

There's a number of useful scripts in the distribution's eg/ directory. Take power for example, written by Martin Streicher <martin.streicher@apress.com>: I lets you perform a power search using Amazon's query language. To search for all books written by Randal Schwartz about Perl, call this from the command line:

power 'author: schwartz subject: perl'

Note that you need to quote the query string to pass it as one argument to power. If a power search returns more results than you want to process at a time, just limit the number of pages, telling power which page to start at (-s) and which one to finish with (-f). Here's a search for all books on the subject computer, limited to the first 10 pages:

power -s 1 -f 10 'subject: computer'

Check out the script power in eg/ for more options.

HOW TO SEND ME PATCHES

If you want me to include your modification or enhancement in the distribution of Net::Amazon, please do the following:

• Work off the latest CVS version. Here's the steps to get it:

  CVSROOT=:pserver:anonymous@cvs.net-amazon.sourceforge.net:/cvsroot/net-amazon
  export CVSROOT
  cvs login (just hit Enter)
  cvs co Net-Amazon

  This will create a new Net-Amazon directory with the latest development version of Net::Amazon on your local machine.

• Apply your changes to this development tree.

• Run a diff between the tree and your changes it in this way:

  cd Net-Amazon
  cvs diff -Nau >patch_to_christopher.txt

• Email me patch_to_christopher.txt. If your patch works (and you've included test cases and documentation), I'll apply it on the spot.

INSTALLATION

Net::Amazon depends on Log::Log4perl, which can be pulled from CPAN by simply saying

perl -MCPAN -eshell 'install Log::Log4perl'

Also, it needs LWP::UserAgent and XML::Simple 2.x, which can be obtained in a similar way.

Once all dependencies have been resolved, Net::Amazon installs with the typical sequence

perl Makefile.PL
make
make test
make install

Make sure you're connected to the Internet while running make test because it will actually contact amazon.com and run a couple of live tests.

The module's distribution tarball and documentation are available at

http://perlmeister.com/devel/#amzn 

and on CPAN.

SEE ALSO

The following modules play well within the Net::Amazon framework:

Net::Amazon::RemoteCart

by David Emery <dave@skiddlydee.com> provides a complete API for creating Amazon shopping carts on a local site, managing them and finally submitting them to Amazon for checkout. It is available on CPAN.

CONTACT

The Net::Amazon project's home page is hosted on

http://net-amazon.sourceforge.net

where you can find documentation, news and the latest development and stable releases for download. If you have questions about how to use Net::Amazon, want to report a bug or just participate in its development, please send a message to the mailing list net-amazon-devel@lists.sourceforge.net

The source code has moved from sourceforge.net to github.com. The git URL is

git://github.com/boumenot/p5-Net-Amazon.git

The hope is that github.com makes collaboration much easier, and git is a much more modern SCM tool.

AUTHOR

Mike Schilli, <na@perlmeister.com> (Please contact me via the mailing list: net-amazon-devel@lists.sourceforge.net )

Maintainers: Christopher Boumenot, <boumenot+na@gmail.com>

Contributors (thanks y'all!):

Andy Grundman <andy@hybridized.org>
Barnaby Claydon <bclaydon@perseus.com>
Batara Kesuma <bkesuma@gaijinweb.com>
Bill Fitzpatrick
Brian <brianbrian@gmail.com>
Brian Hirt <bhirt@mobygames.com>
Dan Kreft <dan@kreft.net>
Dan Sully <daniel@electricrain.com>
Dave Cardwell <http://davecardwell.co.uk/>
Jackie Hamilton <kira@cgi101.com>
Konstantin Gredeskoul <kig@get.topica.com>
Lance Cleveland <lancec@proactivewm.com>
Martha Greenberg <marthag@mit.edu>
Martin Streicher <martin.streicher@apress.com>
Mike Evron <evronm@dtcinc.net>
Padraic Renaghan <padraic@renaghan.com>
rayg <rayg@varchars.com>
Robert Graff <rgraff@workingdemo.com>
Robert Rothenberg <wlkngowl@i-2000.com>
Steve Rushe <steve@deeden.co.uk>
Tatsuhiko Miyagawa <miyagawa@livedoor.jp>
Tony Bowden <tony@kasei.com>
Vince Veselosky

COPYRIGHT AND LICENSE

Copyright 2003, 2004 by Mike Schilli <na@perlmeister.com> Copyright 2007-2009 by Christopher Boumenot <boumenot+na@gmail.com>

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

cpanm Net::Amazon

perl -MCPAN -e shell
install Net::Amazon