C4/Boolean.pm

   1 package C4::Boolean;
   2
   3 #package to handle Boolean values in the parameters table
   4 # Note: This is just a utility module; it should not be instantiated.
   5
   6
   7 # Copyright 2003 Katipo Communications
   8 #
   9 # This file is part of Koha.
  10 #
  11 # Koha is free software; you can redistribute it and/or modify it under the
  12 # terms of the GNU General Public License as published by the Free Software
  13 # Foundation; either version 2 of the License, or (at your option) any later
  14 # version.
  15 #
  16 # Koha is distributed in the hope that it will be useful, but WITHOUT ANY
  17 # WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  18 # A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
  19 #
  20 # You should have received a copy of the GNU General Public License along with
  21 # Koha; if not, write to the Free Software Foundation, Inc., 59 Temple Place,
  22 # Suite 330, Boston, MA  02111-1307 USA
  23
  24 use strict;
  25 use POSIX;
  26
  27 use vars qw($VERSION @ISA @EXPORT @EXPORT_OK);
  28
  29 BEGIN {
  30         # set the version for version checking
  31         $VERSION = 0.02;
  32         require Exporter;
  33         @EXPORT = qw(
  34                 &INVALID_BOOLEAN_STRING_EXCEPTION
  35     );
  36         @EXPORT_OK = qw(
  37                 true_p
  38     );
  39         @ISA = qw(Exporter);
  40 }
  41
  42 =head1 NAME
  43
  44 C4::Boolean - Convenience functions to handle boolean values
  45 in the parameter table
  46
  47 =head1 SYNOPSIS
  48
  49   use C4::Boolean;
  50
  51 =head1 DESCRIPTION
  52
  53 In the parameter table, there are various Boolean values that
  54 variously require a 0/1, no/yes, false/true, or off/on values.
  55 This module aims to provide scripts a means to interpret these
  56 Boolean values in a consistent way which makes common sense.
  57
  58 =head1 FUNCTIONS
  59
  60 =over 2
  61
  62 =cut
  63
  64 sub INVALID_BOOLEAN_STRING_EXCEPTION ()
  65     { 'The given value does not seem to be interpretable as a Boolean value' }
  66
  67 use vars qw( %strings );
  68
  69 %strings = (
  70    '0'     => 0,        '1'     => 1,   # C
  71                         '-1'    => 1,   # BASIC
  72    'nil'   => 0,        't'     => 1,   # LISP
  73    'false' => 0,        'true'  => 1,   # Pascal
  74    'off'   => 0,        'on'    => 1,
  75    'no'    => 0,        'yes'   => 1,
  76    'n'     => 0,        'y'     => 1,
  77 );
  78
  79 =item true_p
  80
  81     if ( C4::Boolean::true_p(C4::Context->preference("insecure")) ) {
  82         ...
  83     }
  84
  85 Tries to interpret the passed string as a Boolean value. Returns
  86 the value if the string can be interpreted as such; otherwise an
  87 exception is thrown.
  88
  89 =cut
  90
  91 sub true_p ($) {
  92     my($x) = @_;
  93     my $it;
  94     if (!defined $x || ref($x) ne '') {
  95         die INVALID_BOOLEAN_STRING_EXCEPTION;
  96     }
  97     $x = lc($x);
  98     $x =~ s/\s//g;
  99     if (defined $strings{$x}) {
 100         $it = $strings{$x};
 101     } else {
 102         die INVALID_BOOLEAN_STRING_EXCEPTION;
 103     }
 104     return $it;
 105 }
 106
 107
 108 #---------------------------------
 109
 110 END { }       # module clean-up code here (global destructor)
 111
 112 1;
 113 __END__
 114
 115 =back
 116
 117 =head1 AUTHOR
 118
 119 Koha Developement team <info@koha.org>
 120
 121 =cut