1 package ObjectProperty;
   2 #
   3 # $RCSfile: ObjectProperty.pm,v $
   4 # $Date: 2011/12/16 00:04:11 $
   5 # $Revision: 1.19 $
   6 #
   7 # Author: Manish Sud <msud@san.rr.com>
   8 #
   9 # Copyright (C) 2004-2012 Manish Sud. All rights reserved.
  10 #
  11 # This file is part of MayaChemTools.
  12 #
  13 # MayaChemTools is free software; you can redistribute it and/or modify it under
  14 # the terms of the GNU Lesser General Public License as published by the Free
  15 # Software Foundation; either version 3 of the License, or (at your option) any
  16 # later version.
  17 #
  18 # MayaChemTools is distributed in the hope that it will be useful, but without
  19 # any warranty; without even the implied warranty of merchantability of fitness
  20 # for a particular purpose.  See the GNU Lesser General Public License for more
  21 # details.
  22 #
  23 # You should have received a copy of the GNU Lesser General Public License
  24 # along with MayaChemTools; if not, see <http://www.gnu.org/licenses/> or
  25 # write to the Free Software Foundation Inc., 59 Temple Place, Suite 330,
  26 # Boston, MA, 02111-1307, USA.
  27 #
  28 
  29 use strict;
  30 use Carp;
  31 
  32 use vars qw($AUTOLOAD);
  33 
  34 # Set property for an object...
  35 sub SetProperty {
  36   my($This, $Name, $Value) = @_;
  37 
  38   if (!(defined($Name) && defined($Value))) {
  39     return undef;
  40   }
  41   return $This->_SetProperty($Name, $Value);
  42 }
  43 
  44 # Set properties for an object...
  45 sub SetProperties {
  46   my($This, %NamesAndValues) = @_;
  47   my($Name, $Value);
  48 
  49   while (($Name, $Value) = each  %NamesAndValues) {
  50     $This->_SetProperty($Name, $Value);
  51   }
  52 
  53   return $This;
  54 }
  55 
  56 # Set object property...
  57 sub _SetProperty {
  58   my($This, $Name, $Value) = @_;
  59 
  60   $This->{$Name} = $Value;
  61 }
  62 
  63 # Get property for an object...
  64 sub GetProperty {
  65   my($This, $Name) = @_;
  66 
  67   if (!defined $Name) {
  68     return undef;
  69   }
  70   return $This->_GetProperty($Name);
  71 }
  72 
  73 # Get object property...
  74 sub _GetProperty {
  75   my($This, $Name) = @_;
  76 
  77   if (exists $This->{$Name}) {
  78     return $This->{$Name};
  79   }
  80   else {
  81     return undef;
  82   }
  83 }
  84 
  85 # Does this property exist?
  86 sub HasProperty {
  87   my($This, $Name) = @_;
  88 
  89   if (!defined $Name) {
  90     return 0;
  91   }
  92   return (exists $This->{$Name}) ? 1 : 0;
  93 }
  94 
  95 # Delete object property...
  96 sub DeleteProperty {
  97   my($This, $Name) = @_;
  98 
  99   if (!defined $Name) {
 100     return undef;
 101   }
 102   return $This->_DeleteProperty($Name);
 103 }
 104 
 105 # Delete object property...
 106 sub _DeleteProperty {
 107   my($This, $Name) = @_;
 108 
 109   if (exists $This->{$Name}) {
 110     delete $This->{$Name};
 111   }
 112   return $This;
 113 }
 114 
 115 # Implements Set<PropertyName> and Get<PropertyName> methods...
 116 sub AUTOLOAD {
 117   my($This, $PropertyValue) = @_;
 118   my($PackageName, $MethodName, $PropertyName, $ThisType);
 119 
 120   ($PackageName, $MethodName) = $AUTOLOAD =~ /^(.*?)::(.*?)$/;
 121 
 122   if ($MethodName =~ /^(BEGIN|DESTROY)$/) {
 123     return;
 124   }
 125 
 126   $ThisType = ref($This) or croak "Error: Invocation of function ${PackageName}::${MethodName} invocation is not supported: It must be invoked using an object reference...";
 127 
 128   if (!($MethodName =~ /^Get/ || $MethodName =~ /^Set/ || $MethodName =~ /^Delete/)) {
 129     croak "Error: Can't locate object method \"$MethodName\" via package \"$ThisType\": This method is not automatically implemented by AUTOLOAD: Only Get<PropertyName>, Set<PropertyName> and Delete<PropertyName> functions are implemented via AUTOLOAD...";
 130   }
 131   if ($MethodName =~ /^Delete/) {
 132     ($PropertyName) = $MethodName =~ /^Delete(.*?)$/;
 133   }
 134   else {
 135     ($PropertyName) = $MethodName =~ /^[SG]et(.*?)$/;
 136   }
 137   if ($MethodName =~ /^Set/ && !defined($PropertyValue)) {
 138     carp "Warning:  ${PackageName}::${MethodName}: Didn't set value for property $PropertyName: Property value for must be specified...\n";
 139     return undef;
 140   }
 141 
 142   if ($MethodName =~ /^Get/) {
 143     return $This->_GetProperty($PropertyName);
 144   }
 145   elsif ($MethodName =~ /^Set/) {
 146     return $This->_SetProperty($PropertyName, $PropertyValue);
 147   }
 148   elsif ($MethodName =~ /^Delete/) {
 149     return $This->_DeleteProperty($PropertyName);
 150   }
 151 
 152 }
 153