1 |
## --------------------------------------------------------------------------- |
2 |
## $Id: Object.pm,v 1.2 2002/12/27 16:05:42 joko Exp $ |
3 |
## --------------------------------------------------------------------------- |
4 |
## $Log: Object.pm,v $ |
5 |
## Revision 1.2 2002/12/27 16:05:42 joko |
6 |
## + played with Devel::CallerItem and Devel::StackTrace |
7 |
## |
8 |
## Revision 1.1 2002/12/13 21:46:29 joko |
9 |
## + initial check-in |
10 |
## |
11 |
## --------------------------------------------------------------------------- |
12 |
|
13 |
|
14 |
package DesignPattern::Object; |
15 |
|
16 |
use strict; |
17 |
use warnings; |
18 |
|
19 |
|
20 |
use Data::Dumper; |
21 |
#use Devel::CallerItem; |
22 |
#use Devel::StackTrace; |
23 |
|
24 |
|
25 |
# get logger instance |
26 |
my $logger = Log::Dispatch::Config->instance; |
27 |
|
28 |
sub new { |
29 |
|
30 |
# the classname in most cases |
31 |
my $classname = shift; |
32 |
|
33 |
# use already blessed reference, if passed in - else use the very classname |
34 |
my $class = ref ($classname) || $classname; |
35 |
|
36 |
$logger->debug( "$classname->new( ... )" . "\t[via " . __PACKAGE__ . "]" ); |
37 |
|
38 |
# the base for our object - a plain perl hash, which .... |
39 |
my $self = {}; |
40 |
# note: |
41 |
# this makes an instance of an arbitrary perl variable, |
42 |
# the most often used for this purpose is - guess it - the hash, |
43 |
# since it resembles object-properties in a convenient way: |
44 |
# $object->{property} = 'Hello World!'; |
45 |
# if you _do_ care about privacy you might take a look |
46 |
# at CPAN's Tie::SecureHash or Class::Contract ... have fun! |
47 |
|
48 |
# TODO: what about logging in here? inherit from |
49 |
# DesignPattern::Object::Logger for this purpose.... |
50 |
# ... or would this give us (harmful) circular module dependencies??? |
51 |
#$logger->debug( __PACKAGE__ . "->new( @args )" ); # this is not "common"! |
52 |
|
53 |
|
54 |
# remember the stacktrace: abstract this out (DesignPattern::Object::Trace) or parametrize! |
55 |
#my $trace = Devel::StackTrace->new(); |
56 |
#print Dumper($trace); |
57 |
#print Dumper($trace->frame(1)->args()); |
58 |
|
59 |
#print "args: ", $self->{'__caller'}->hasargs(), "\n"; |
60 |
|
61 |
#print Dumper($self); |
62 |
#exit; |
63 |
|
64 |
|
65 |
# argument-handling ... |
66 |
|
67 |
# ... get them ... |
68 |
my @args = (); |
69 |
@_ && (@args = @_); |
70 |
|
71 |
# ... check if we can coerce them into an array (this needs an even number of arguments) |
72 |
my $argcount = $#args + 1; |
73 |
my $fract = $argcount / 2; |
74 |
|
75 |
my $seperate = pop @args if $fract != int($fract); |
76 |
|
77 |
# mixin arguments |
78 |
$self = { @args }; |
79 |
|
80 |
# mixin seperate |
81 |
$self->{'__arg'} = $seperate if $seperate; |
82 |
|
83 |
# ... bless hash into object using classname |
84 |
bless $self, $class; |
85 |
|
86 |
# remember the caller |
87 |
$self->{'__caller'} = caller; |
88 |
#print Dumper(caller(2)); |
89 |
#exit; |
90 |
|
91 |
$self->{__classname} = $classname; |
92 |
|
93 |
$self->_init() if $self->can('_init'); |
94 |
|
95 |
return $self; |
96 |
} |
97 |
|
98 |
sub _abstract_function { |
99 |
my $self = shift; |
100 |
my $self_classname = ref $self; |
101 |
my $function_name = shift; |
102 |
# was: |
103 |
$logger->warning( __PACKAGE__ . ": function '$function_name' is an abstract method, please implement it in '$self_classname'."); |
104 |
# is: |
105 |
#die( __PACKAGE__ . ": Function '$function_name' is an abstract method, please implement it in '$self_classname'."); |
106 |
#exit; |
107 |
} |
108 |
|
109 |
sub fromPackage { |
110 |
my $self = shift; |
111 |
#my $self_classname = ref $self; |
112 |
my $pkgname = shift; |
113 |
my @args = @_; |
114 |
# my $args = shift; |
115 |
|
116 |
# my $caller = $self->{'__caller'}; |
117 |
|
118 |
#print Dumper($args); |
119 |
|
120 |
$logger->debug( __PACKAGE__ . "->fromPackage( pkgname $pkgname args @args )" ); |
121 |
|
122 |
# perl-load |
123 |
my $evstring = "use $pkgname;"; |
124 |
eval($evstring); |
125 |
|
126 |
# report errors |
127 |
if ($@) { |
128 |
# build error-messages |
129 |
my $errmsg_native = __PACKAGE__ . ':' . __LINE__ . " Error in eval \"$evstring\": " . $@; |
130 |
#my $classname = $self->{__classname}; |
131 |
my $errmsg_critical = ''; |
132 |
if ($errmsg_native =~ m/Can't locate (.+?) in \@INC/) { |
133 |
$errmsg_critical = "Could not instantiate object from package '$pkgname' - location of '$1' failed."; |
134 |
} else { |
135 |
$errmsg_critical = $errmsg_native; |
136 |
} |
137 |
# write error to logging-output (console|file|database) |
138 |
$logger->debug( $errmsg_native ); |
139 |
$logger->critical( $errmsg_critical ); |
140 |
return; |
141 |
} |
142 |
|
143 |
# object-creation |
144 |
my $object = $pkgname->new(@args); |
145 |
|
146 |
# run boot-methods on object |
147 |
$object->_init() if $object->can('_init'); |
148 |
|
149 |
return $object; |
150 |
} |
151 |
|
152 |
1; |