WebService::ISBNDB::Agent is a base Perl class for data-retrieval agents.
use base 'WebService::ISBNDB::Agent';
The WebService::ISBNDB::Agent class is a base class for all the classes that provide actual communication protocol support for the WebService::ISBNDB::API module. Unlike the API class, this class is not usable on its own except as a factory to create instances of classes that derive from it.
The agent classes are responsible for actually setting up the web requests to retrieve data, parsing the results of those calls, and returning the data in formats usable by the API classes.
This class (and all sub-classes of it) are based on the Class::Std inside-out objects pattern. See Class::Std for more detail.
All error conditions in the methods of this class are handled using the exception model provided by the Error module. Most errors are thrown in the form of Error::Simple exception objects. See Error for more detail.