NAME

WWW::Scraper::ISBN::Driver - Driver class for WWW::Scraper::ISBN module.

SYNOPSIS

    use WWW::Scraper::ISBN::Driver;
    $driver = WWW::Scraper::ISBN->driver();
    $driver->search($isbn);
    if ($driver->found) { ... }
    $driver->verbosity(1);
    print $driver->book{'title'};
    print $driver->error;

REQUIRES

Requires the following modules be installed:

    Carp

DESCRIPTION

This is a base class, all site-specific drivers should inherit its members and methods. Driver subclasses named '$name' should be packaged as WWW::Scraper::ISBN::$name_Driver, e.g. WWW::Scraper::ISBN::LOC_Driver for LOC (Library of Congress) driver. Each driver need only implement the search() method, though they may have as many other methods as they need to get their job done. Only search() will be called by WWW::Scraper::ISBN->search().

Standard Fields

It is important that the different drivers return at least a core set of information, though they may return additional information. The following self-explanatory fields should exist in $driver-book>:

author

title

isbn

Additional standard fields may be added in the future. 'volume' and 'edition' are common. In some cases, there may be no information available for 'volume' or 'edition', and so these may be set to the empty string. However, they must still be set in the hash!

Expiration

Due to the dynamic, ever-changing nature of the web, it is highly likely that the site from which many of these drivers glean their information will change. Hopefully, driver maintainers will keep drivers up to date, but they will all expire, and may behave unexpectedly. Keep this in mind if the driver continually returns weird results.

Export

None by default.

METHODS

The following methods are provided by WWW::Scraper::ISBN::Driver:

    $drv = WWW::Scraper::ISBN::Driver->new()

Class constructor. Creates new driver object and returns a reference to it. Sets the following default values:

    found = 0;
    verbosity = 0;
    book = undef;
    error = "";

found() or found($bool)

    if ($drv->found) { # ... }
    $drv->found(1);

Accessor/Mutator method for handling the search status of this record. This is 0 by default, and should only be set true if search was deemed successful and $driver->book contains appropriate information.

verbosity() or verbosity($level)

    $driver->verbosity(3);
    if ($driver->verbosity == 2) { print "blah blah blah"; }

Accessor/Mutator method for handling the verbosity level to be generated by this driver as it is going. This can be used to print useful information by the driver as it is running.

book() or book($hashref)

    my $book = $drv->book;
    print $book->{'title'}; 
    print $book->{'author'};
    $another_book = { 'title' => "Some book title",
        'author' => "Author of some book"
    };
    $drv->book( $another_book );

Accessor/Mutator method for handling the book information retrieved by the driver. The driver should create an anonymous hash containing the standard fields. WWW::Scraper::ISBN->search sets the WWW::Scraper::ISBN::Record->book() field to this value.

error() or error($error_string)

    print $driver->error;
    $driver->error("Invalid ISBN number, or some similar error.");

Accessor/Mutator method for handling any errors which occur during the search. The search drivers may add errors to record fields, which may be useful in gleaning information about failed searches.

search($isbn)

    my $record = $driver->search("123456789X");

Searches for information on the given ISBN number. Each driver must define its own search routine, doing whatever is necessary to retrieve the desired information. If found, it should set $driver->found and $driver->book accordingly.

SEE ALSO

WWW::Scraper::ISBN

WWW::Scraper::ISBN::Record

No mailing list or website currently available. Primary development done through CSX ( http://csx.calvin.edu/ ).

AUTHOR

Andy Schamp, <andy@schamp.net>

COPYRIGHT AND LICENSE

Copyright 2004 by Andy Schamp

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