/usr/man2/cat.3/Class::ISA.3.Z
NAME
Class::ErrorHandler - Base class for error handling
SYNOPSIS
package Foo;
use base qw( Class::ErrorHandler );
sub class_method {
my $class = shift;
...
return $class->error("Help!")
unless $continue;
}
sub object_method {
my $obj = shift;
...
return $obj->error("I am no more")
unless $continue;
}
package main;
use Foo;
Foo->class_method or die Foo->errstr;
my $foo = Foo->new;
$foo->object_method or die $foo->errstr;
DESCRIPTION
Class::ErrorHandler provides an error-handling mechanism that's generic
enough to be used as the base class for a variety of OO classes. Sub-
classes inherit its two error-handling methods, error and errstr, to
communicate error messages back to the calling program.
On failure (for whatever reason), a subclass should call error and
return to the caller; error itself sets the error message internally,
then returns "undef". This has the effect of the method that failed
returning "undef" to the caller. The caller should check for errors by
checking for a return value of "undef", and calling errstr to get the
value of the error message on an error.
As demonstrated in the SYNOPSIS, error and errstr work as both class
methods and object methods.
USAGE
Class->error($message)
$object->error($message)
Sets the error message for either the class Class or the object $object
to the message $message. Returns "undef".
Class->errstr
$object->errstr
Accesses the last error message set in the class Class or the object
$object, respectively, and returns that error message.
LICENSE
Class::ErrorHandler is free software; you may redistribute it and/or
modify it under the same terms as Perl itself.
AUTHOR & COPYRIGHT
Except where otherwise noted, Class::ErrorHandler is Copyright 2004
Benjamin Trott, cpan@stupidfool.org. All rights reserved.
perl v5.8.8 2004-08-15 Class::ErrorHandler(3)
See also Class::ISA(3)
See also Class::Loader(3)
See also Class::Struct(3)
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