NAME

EO - A generic base class

SYNOPSIS

        package Some::Package
        use EO;

        use base qw(EO);

        sub init {
          my $self = shift;

          if ($self->SUPER::init( @_ ) {
            # .. perform initilisation
            return 1;
          }

          return 0;
        }

DESCRIPTION

This is a base class for the EO module tree. EO is designed to be a well tested, solid, simple, and long living base class that other modules can rely on.

CONSTRUCTOR

new()

        The constructor takes no arguments and will call the init method.
        The programmer should ensure that the init method in turn calls its
        SUPER::init method. If the EO init method is not called then a
        warning will be issued to the effect. Furthermore the init method
        should return true to the constructor. Your init method should
        probably look something like this:

          sub init {
            my $self = shift;
            if ($self->SUPER::init( @_ )) {
              # ... perform initialisation ...
              return 1;
            }
            return 0;
          }

        This will ensure that the initialisation occurs all the way up the
        parent-class chain.

METHODS

oid()

        Returns the object id of this object. Object id's are UUIDs as
        created by the Data::UUID module.

generate_oid()

Returns a new object id.

clone()

        The clone method is creates a copy of the object and returns it.
        This is the only method that should be used for cloning in order to
        preserve id's. The clone method guarantees that all objects
        contained within an object that respond true to ->isa('EO') will
        have their id's regenerated.

ATTRIBUTES

abstract

        The abstract attribute can be assigned to any method. When it is
        assigned it will cause any attempt to call that method to throw an
        EO::Error::Method::Abstract exception. This will happen at runtime.

private

        The private attribute can be assigned to any method. Any attempt to
        call this method from outside the package it is defined in will
        cause an EO::Error::Method::Private exception to be thrown. This
        will happen at runtime.

EXCEPTIONS

EO::Error::New;

        This exception is thrown whenever the constructor fails to
        successfully initialise an object. This usually occurs when the
        init() method does not return a true value.

EO::Error::Method::NotFound

        This exception is thrown whenever a message sent to an object cannot
        be successfully sent.

EO::Error::Method::Abstract

        This exception is thrown whenever there is a method call on a method
        marked with the abstract attribute.

EO::Error::Method::Private

        This exception is thrown whenever there is a method call from
        outside the defining package on a method marked with the private
        attribute.

EO::Error::InvalidParameters

        This exception is throw whenever the a message is sent to an object
        with incorrect parameters.

AUTHOR

        Arthur Bergman <abergman@fotango.com> James A. Duncan
        <jduncan@fotango.com>

COPYRIGHT

Copyright 2004 Fotango Ltd. All Rights Reserved.

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

SEE ALSO

perl(1), Data::UUID(3)