Initial Commit

database/perl/vendor/lib/Class/ErrorHandler.pm

@@ -0,0 +1,101 @@
+# $Id: ErrorHandler.pm,v 1.1.1.1 2004/08/15 14:55:43 btrott Exp $
+
+package Class::ErrorHandler;
+use strict;
+
+use vars qw( $VERSION $ERROR );
+$VERSION = '0.04';
+
+sub error {
+    my $msg = $_[1] || '';
+    if (ref($_[0])) {
+        $_[0]->{_errstr} = $msg;
+    } else {
+        $ERROR = $msg;
+    }
+    return;
+}
+
+sub errstr {
+    ref($_[0]) ? $_[0]->{_errstr} : $ERROR
+}
+
+1;
+__END__
+
+=for stopwords errstr
+
+=head1 NAME
+
+Class::ErrorHandler - Base class for error handling
+
+=head1 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 $foo->errstr;
+
+=head1 DESCRIPTION
+
+I<Class::ErrorHandler> provides an error-handling mechanism that's generic
+enough to be used as the base class for a variety of OO classes. Subclasses
+inherit its two error-handling methods, I<error> and I<errstr>, to
+communicate error messages back to the calling program.
+
+On failure (for whatever reason), a subclass should call I<error> and return
+to the caller; I<error> itself sets the error message internally, then
+returns C<undef>. This has the effect of the method that failed returning
+C<undef> to the caller. The caller should check for errors by checking for a
+return value of C<undef>, and calling I<errstr> to get the value of the
+error message on an error.
+
+As demonstrated in the L<SYNOPSIS>, I<error> and I<errstr> work as both class
+methods and object methods.
+
+=head1 USAGE
+
+=head2 Class->error($message)
+
+=head2 $object->error($message)
+
+Sets the error message for either the class I<Class> or the object
+I<$object> to the message I<$message>. Returns C<undef>.
+
+=head2 Class->errstr
+
+=head2 $object->errstr
+
+Accesses the last error message set in the class I<Class> or the
+object I<$object>, respectively, and returns that error message.
+
+=head1 LICENSE
+
+This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
+
+=head1 AUTHOR & COPYRIGHT
+
+Except where otherwise noted, I<Class::ErrorHandler> is Copyright 2004
+Benjamin Trott, cpan@stupidfool.org. All rights reserved.
+
+=cut