102 lines
2.4 KiB
Perl
102 lines
2.4 KiB
Perl
# $Id: ErrorHandler.pm,v 1.1.1.1 2004/08/15 14:55:43 btrott Exp $
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package Class::ErrorHandler;
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use strict;
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use vars qw( $VERSION $ERROR );
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$VERSION = '0.04';
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sub error {
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my $msg = $_[1] || '';
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if (ref($_[0])) {
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$_[0]->{_errstr} = $msg;
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} else {
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$ERROR = $msg;
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}
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return;
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}
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sub errstr {
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ref($_[0]) ? $_[0]->{_errstr} : $ERROR
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}
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1;
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__END__
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=for stopwords errstr
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=head1 NAME
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Class::ErrorHandler - Base class for error handling
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=head1 SYNOPSIS
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package Foo;
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use base qw( Class::ErrorHandler );
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sub class_method {
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my $class = shift;
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...
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return $class->error("Help!")
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unless $continue;
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}
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sub object_method {
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my $obj = shift;
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...
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return $obj->error("I am no more")
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unless $continue;
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}
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package main;
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use Foo;
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Foo->class_method or die Foo->errstr;
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my $foo = Foo->new;
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$foo->object_method or die $foo->errstr;
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=head1 DESCRIPTION
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I<Class::ErrorHandler> provides an error-handling mechanism that's generic
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enough to be used as the base class for a variety of OO classes. Subclasses
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inherit its two error-handling methods, I<error> and I<errstr>, to
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communicate error messages back to the calling program.
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On failure (for whatever reason), a subclass should call I<error> and return
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to the caller; I<error> itself sets the error message internally, then
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returns C<undef>. This has the effect of the method that failed returning
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C<undef> to the caller. The caller should check for errors by checking for a
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return value of C<undef>, and calling I<errstr> to get the value of the
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error message on an error.
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As demonstrated in the L<SYNOPSIS>, I<error> and I<errstr> work as both class
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methods and object methods.
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=head1 USAGE
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=head2 Class->error($message)
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=head2 $object->error($message)
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Sets the error message for either the class I<Class> or the object
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I<$object> to the message I<$message>. Returns C<undef>.
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=head2 Class->errstr
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=head2 $object->errstr
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Accesses the last error message set in the class I<Class> or the
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object I<$object>, respectively, and returns that error message.
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=head1 LICENSE
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This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
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=head1 AUTHOR & COPYRIGHT
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Except where otherwise noted, I<Class::ErrorHandler> is Copyright 2004
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Benjamin Trott, cpan@stupidfool.org. All rights reserved.
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=cut
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