1#
2# $Id: Gomor.pm 2000 2015-01-13 18:24:09Z gomor $
3#
4package Class::Gomor;
5use strict; use warnings;
6
7our $VERSION = '1.03';
8
9use Exporter;
10use base qw(Exporter);
11
12use Carp;
13
14no strict 'refs';
15
16our $Debug   = 0;
17our $NoCheck = 0;
18our @EXPORT_OK = qw($Debug $NoCheck);
19
20sub cgCheckParams {
21   my $self = shift;
22   my ($userParams, $accessors) = @_;
23   for my $u (keys %$userParams) {
24      my $valid;
25      my $defined;
26      for (@$accessors) {
27         ($u eq $_) ? $valid++ : next;
28         defined($userParams->{$u}) && do { $defined++; last };
29      }
30      if (! $valid) {
31         carp("$self: parameter is invalid: `$u'");
32         next;
33      }
34      if (! $defined) {
35         carp("$self: parameter is undef: `$u'");
36         next;
37      }
38   }
39}
40
41sub cgGetIsaTree {
42   my $self = shift;
43   my ($classes) = @_;
44   for (@{$self.'::ISA'}) {
45      push @$classes, $_;
46      $_->cgGetIsaTree($classes) if $_->can('cgGetIsaTree');
47   }
48}
49
50sub cgGetAttributes {
51   my $self = shift;
52   my $classes = [ $self ];
53   $self->cgGetIsaTree($classes);
54   my @attributes = ();
55   {
56      # On perl 5.10.0, we have a warning message:
57      # "::AS" used only once: possible typo ...
58      no warnings;
59      for (@$classes) {
60         push @attributes, @{$_.'::AS'} if @{$_.'::AS'};
61         push @attributes, @{$_.'::AA'} if @{$_.'::AA'};
62         push @attributes, @{$_.'::AO'} if @{$_.'::AO'};
63      }
64   }
65   \@attributes;
66}
67
68sub cgClone {
69   my $self = shift;
70   my $class = ref($self) || $self;
71   return bless([ @$self ], $class)
72      if UNIVERSAL::isa($self, 'Class::Gomor::Array');
73   return bless({ %$self }, $class)
74      if UNIVERSAL::isa($self, 'Class::Gomor::Hash');
75   $self;
76}
77
78sub cgFullClone {
79   my $self = shift;
80   my ($n) = @_;
81   return [ map { $self->cgFullClone } 1..$n ];
82}
83
84sub cgBuildAccessorsScalar {
85   my $self = shift;
86   my ($accessors) = @_;
87   for my $a (@$accessors) {
88      *{$self.'::'.$a} = sub { shift->_cgAccessorScalar($a, @_) }
89   }
90}
91
92sub cgBuildAccessorsArray {
93   my $self = shift;
94   my ($accessors) = @_;
95   for my $a (@{$accessors}) {
96      *{$self.'::'.$a} = sub { shift->_cgAccessorArray($a, @_) }
97   }
98}
99
100sub cgDebugPrint {
101   my $self = shift;
102   my ($level, $msg) = @_;
103   return if $Debug < $level;
104   my $class = ref($self) || $self;
105   $class =~ s/^.*:://;
106   $msg =~ s/^/DEBUG: $class: /gm;
107   print STDERR $msg."\n";
108}
109
1101;
111
112=head1 NAME
113
114Class::Gomor - another class and object builder
115
116=head1 DESCRIPTION
117
118This module is yet another class builder. This one adds parameter checking in B<new> constructor, that is to check for attributes existence, and definedness.
119
120In order to validate parameters, the module needs to find attributes, and that is the reason for declaring attributes in global variables named B<@AS>, B<@AA>, B<@AO>. They respectively state for Attributes Scalar, Attributes Array and Attributes Other. The last one is used to avoid autocreation of accessors, that is to let you declare your own ones.
121
122Attribute validation is performed by looking at classes hierarchy, by following @ISA tree inheritance.
123
124The loss in speed by validating all attributes is quite negligeable on a decent machine (Pentium IV, 2.4 GHz) with Perl 5.8.x. But if you want to avoid checking, you can do it, see below.
125
126This class is the base class for B<Class::Gomor::Array> and B<Class::Gomor::Hash>, so they will inherite the following methods.
127
128=head1 GLOBAL VARIABLES
129
130=over 4
131
132=item B<$NoCheck>
133
134Import it in your namespace like this:
135
136use Class::Gomor qw($NoCheck);
137
138If you want to disable B<cgCheckParams> to improve speed once your program is frozen, you can use this variable. Set it to 1 to disable parameter checking.
139
140=item B<$Debug>
141
142Import it in your namespace like this:
143
144use Class::Gomor qw($Debug);
145
146This variable is used by the B<cgDebugPrint> method.
147
148=back
149
150=head1 METHODS
151
152=over 4
153
154=item B<cgCheckParams> (hash ref, array ref)
155
156The attribute checking method takes two arguments, the first is user passed attributes (as a hash reference), the second is the list of valid attributes, gathered via B<cgGetAttributes> method (as an array ref). A message is displayed if passed parameters are not valid.
157
158=item B<cgGetIsaTree> (array ref)
159
160A recursive method. You pass a class in an array reference as an argument, and then the @ISA array is browsed, recursively. The array reference passed as an argument is increased with new classes, pushed into it. It returns nothing, result is stored in the array ref.
161
162=item B<cgGetAttributes>
163
164This method returns available attributes for caller's object class. It uses B<cgGetIsaTree> to search recursively in class hierarchy. It then returns an array reference with all possible attributes.
165
166=item B<cgBuildAccessorsScalar> (array ref)
167
168Accessor creation method. Takes an array reference containing all scalar attributes to create. Scalar accessors are stored in a global variable names B<@AS>. So you call this method at the beginning of your class like that:
169
170__PACKAGE__->cgBuildAccessorsScalar(\@AS);
171
172=item B<cgBuildAccessorsArray> (array ref)
173
174Accessor creation method. Takes an array reference containing all array attributes to create. Array accessors are stored in a global variable names B<@AA>. So you call this method at the beginning of your class like that:
175
176__PACKAGE__->cgBuildAccessorsArray(\@AA);
177
178=item B<cgClone> [ (scalar) ]
179
180You can clone one of your objects by calling this method. An optional parameter may be used to create multiple clones. Cloning will occure only on the first level attributes, that is, if you have attributes containing other objects, they will not be cloned.
181
182=item B<cgFullClone> [ (scalar) ]
183
184This method is the same as B<cgClone>, but will clone all attributes recursively, but only if they are subclassed from B<Class::Gomor>. So, objects created with other modules than B<Class::Gomor::Array> or B<Class::Gomor::Hash> will not be cloned.
185
186Another thing to note, there is no catch for cycling references (when you link two objects with each others). You have been warned.
187
188=item B<cgDebugPrint> (scalar, scalar)
189
190First argument is a debug level. It is compared with global B<$Debug>, and if it is less than it, the second argument (a message string) is displayed. This method exists because I use it, maybe you will not like it.
191
192=back
193
194=head1 SEE ALSO
195
196L<Class::Gomor::Array>, L<Class::Gomor::Hash>
197
198=head1 AUTHOR
199
200Patrice E<lt>GomoRE<gt> Auffret
201
202=head1 COPYRIGHT AND LICENSE
203
204Copyright (c) 2004-2015, Patrice E<lt>GomoRE<gt> Auffret
205
206You may distribute this module under the terms of the Artistic license.
207See LICENSE.Artistic file in the source distribution archive.
208
209=cut
210