1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
|
# Movable Type (r) Open Source (C) 2001-2008 Six Apart, Ltd.
# This program is distributed under the terms of the
# GNU General Public License, version 2.
#
# $Id: ErrorHandler.pm 1174 2008-01-08 21:02:50Z bchoate $
package MT::ErrorHandler;
use strict;
use vars qw( $ERROR );
sub new { bless {}, shift }
sub error {
my $class = shift;
my $msg = $_[0] || '';
$msg .= "\n" if ($msg ne '') && ($msg !~ /\n$/);
if (ref($class)) {
$class->{_errstr} = $msg;
} else {
$ERROR = $msg;
}
return;
}
sub trans_error {
my $obj = shift;
return $obj->error($obj->can('translate') ? $obj->translate(@_) : MT->translate(@_));
}
sub errstr { ref($_[0]) ? $_[0]->{_errstr} : $ERROR }
1;
__END__
=head1 NAME
MT::ErrorHandler - MT error handling
=head1 SYNOPSIS
package Foo;
use MT::ErrorHandler;
@Foo::ISA = qw( MT::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 $foo->errstr;
=head1 DESCRIPTION
I<MT::ErrorHandler> provides an error-handling mechanism for all <MT>
modules/classes. It is meant to be used as a base class for classes that wish
to use its error-handling methods: derived classes use its two methods,
I<error> and I<errstr>, to communicate error messages back to the calling
program.
On failure (for whatever reason), a subclass should call I<error> and return
to the caller; I<error> itself sets the error message internally, then returns
C<undef>. This has the effect of the method internally, then returns C<undef>.
This has the effect of the method that failed returning C<undef> to the
caller. The caller should check for errors by checking for a return value of
C<undef>, and in this case should call I<errstr> to get the value of the error
message. Note that calling I<errstr> when an error has not occurred is
undefined behavior and will I<rarely> do what you want.
As demonstrated in the I<SYNOPSIS> (above), I<error> and I<errstr> work both
as class methods and as object methods.
=head1 USAGE
=head2 Class->new
Constructs a new I<MT::ErrorHandler> instance.
=head2 Class->error($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 AUTHOR & COPYRIGHTS
Please see the I<MT> manpage for author, copyright, and license information.
=cut
|
