######################################################################
    Net::Amazon 0.20
######################################################################

NAME
    Net::Amazon - Framework for accessing amazon.com via SOAP and XML/HTTP

SYNOPSIS
      use Net::Amazon;

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

        # 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
      SOAP and XML/HTTP interfaces. 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(
          token     => 'YOUR_AMZN_TOKEN',
          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).

    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. Returns at most one result.

    "$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(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(keyword => "perl xml", mode => "books")"
        Search by keyword, mandatory parameters "keyword" and "mode". Can
        return many results.

    "$ua->search(wishlist => "1XL5DWOUFMFVJ")"
        Search for all items in a specified wishlist. Can return many
        results.

    "$ua->search(upc => "075596278324", mode => "music")"
        Music search by UPC (product barcode), mandatory parameter "upc".
        "mode" has to be set to "music". Returns at most one result.

    "$ua->search(similar => "0201360683")"
        Search for all items similar to the one represented by the ASIN
        provided. Can return many results.

    "$ua->search(power => "subject: perl and author: schwartz", mode =>
    "books")"
        Initiate a power search for all books matching the power query. Can
        return many results. See Net::Amazon::Request::Power for details.

    "$ua->search(manufacturer => "o'reilly", mode => "books")"
        Initiate a search for all items made by a given manufacturrer. Can
        return many results. See Net::Amazon::Request::Manufacturer for
        details.

    The user agent's "search" method returns a response object, which can be
    checked for success or failure:

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

    In case the request succeeds, the response contains one or more Amazon
    'properties', as it calls the products found. All matches can be
    retrieved from the Response object using it's "properties()" method.

    In case the request fails, the response contains one or more error
    messages. The response object's "message()" method will return it (or
    them) as a single string, while "messages()" (notice the plural) will
    return a reference to an array of message strings.

    Response objects always have the methods "is_success()", "is_error()",
    "message()", "as_string()" and "properties()" available.

    "properties()" returns one or more "Net::Amazon::Property" objects of
    type "Net::Amazon::Property" (or one of its subclasses like
    "Net::Amazon::Property::Book", "Net::Amazon::Property::Music" or
    Net::Amazon::Property::DVD), each of which features accessors named
    after the attributes of the product found in Amazon's database:

        for ($resp->properties) {
           print $_->Asin(), " ",
                 $_->OurPrice(), "\n";
        }

    Also the specialized classes "Net::Amazon::Property::Book" and
    "Net::Amazon::Property::Music" feature convenience methods like
    "authors()" (returning the list of authors of a book) or "album()" for
    CDs, returning the album title.

    Customer reviews: Every property features a "review_set()" method which
    returns a "Net::Amazon::Attribute::ReviewSet" object, which in turn
    offers a list of "Net::Amazon::Attribute::Review" objects. Check the
    respective man pages for details on what's available.

  Requests behind the scenes
    "Net::Amazon"'s "search()" method is just a convenient way to create
    different kinds of request objects behind the scenes and trigger them to
    send requests to Amazon.

    Depending on the parameters fed to the "search" method, "Net::Amazon"
    will determine the kind of search requested and create one of the
    following request objects:

    Net::Amazon::Request::ASIN
        Search by ASIN, mandatory parameter "asin". Returns at most one
        result.

    Net::Amazon::Request::Artist
        Music search by Artist, mandatory parameter "artist". Can return
        many results.

    Net::Amazon::Request::BrowseNode
        Returns category (node) listing. Mandatory parameters "browsenode"
        (must be numeric) and "mode". Can return many results.

    Net::Amazon::Request::Keyword
        Keyword search, mandatory parameters "keyword" and "mode". Can
        return many results.

    Net::Amazon::Request::UPC
        Music search by UPC (product barcode), mandatory parameter "upc".
        "mode" has to be set to "music". Returns at most one result.

    Net::Amazon::Request::Blended
        'Blended' search on a keyword, resulting in matches across the
        board. No 'mode' parameter is allowed. According to Amazon's
        developer's kit, this will result in up to three matches per
        category and can yield a total of 45 matches.

    Net::Amazon::Request::Power
        Understands power search strings. See Net::Amazon::Request::Power
        for details. Mandatory parameter "power".

    Net::Amazon::Request::Manufacturer
        Searches for all items made by a given manufacturer. Mandatory
        parameter "manufacturer".

    Check the respective man pages for details on these request objects.
    Request objects are typically created like this (with a Keyword query as
    an example):

        my $req = Net::Amazon::Request::Keyword->new(
            keyword   => 'perl',
            mode      => 'books',
        );

    and are handed over to the user agent like that:

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

    The convenient "search()" method just does these two steps in one.

  METHODS
    $ua = Net::Amazon->new(token => $token, ...)
        Create a new Net::Amazon useragent. $token is the value of the
        mandatory Amazon developer's token, which can be obtained from
        <http://amazon.com/soap>.

        Additional optional parameters:

        "max_pages => $max_pages"
            sets how many result pages the module is supposed to fetch back
            from Amazon, which only sends back 10 results per page.

        "affiliate_id => $affiliate_id"
            your Amazon affiliate ID, if you have one. It defaults to
            "webservices-20" which is currently (as of 06/2003) required by
            Amazon.

    "$resp = $ua->request($request)"
        Sends a request to the Amazon web service. $request is of a
        "Net::Amazon::Request::*" type and $response will be of the
        corresponding "Net::Amazon::Response::*" type.

  Accessing foreign Amazon Catalogs
    As of this writing (07/2003), Amazon also offers its web service for the
    UK, Germany, and Japan. Just pass in

        locale => 'uk'
        locale => 'de'
        locale => 'jp'

    respectively to "Net::Amazon"'s constructor "new()" and instead of
    returning results sent by the US mothership, it will query the
    particular country's catalog and show prices in (gack!) local
    currencies.

  EXAMPLE
    Here's a full-fledged example doing a artist search:

        use Net::Amazon;
        use Net::Amazon::Request::Artist;
        use Data::Dumper;

        die "usage: $0 artist\n(use Zwan as an example)\n"
            unless defined $ARGV[0];

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

        my $req = Net::Amazon::Request::Artist->new(
            artist  => $ARGV[0],
        );

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

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

    And here's one displaying someone's wishlist:

        use Net::Amazon;
        use Net::Amazon::Request::Wishlist;

        die "usage: $0 wishlist_id\n" .
            "(use 1XL5DWOUFMFVJ as an example)\n" unless $ARGV[0];

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

        my $req = Net::Amazon::Request::Wishlist->new(
            id  => $ARGV[0]
        );

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

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

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',
            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);

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_mike.txt

    *   Email me "patch_to_mike.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
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

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

    Contributors (thanks y'all!):

        Barnaby Claydon <bclaydon@perseus.com>
        Bill Fitzpatrick
        Brian Hirt <bhirt@mobygames.com>
        Dan Sully <daniel@electricrain.com>
        Jackie Hamilton <kira@cgi101.com>
        Konstantin Gredeskoul <kig@get.topica.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>
        Tony Bowden <tony@kasei.com>

COPYRIGHT AND LICENSE
    Copyright 2003, 2004 by Mike Schilli <na@perlmeister.com>

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

