| 1 |
## --------------------------------------------------------------------------- |
| 2 |
## $Id: Object.pm,v 1.7 2003/02/18 18:34:35 joko Exp $ |
| 3 |
## --------------------------------------------------------------------------- |
| 4 |
## $Log: Object.pm,v $ |
| 5 |
## Revision 1.7 2003/02/18 18:34:35 joko |
| 6 |
## + fix: just logs if possible (sub log_basic) |
| 7 |
## |
| 8 |
## Revision 1.6 2003/02/11 11:04:27 joko |
| 9 |
## + metadata (args, caller, etc.) are now stored inside {__bridge} |
| 10 |
## |
| 11 |
## Revision 1.5 2003/02/09 16:24:46 joko |
| 12 |
## + pseudo constructor mechanism by calling method 'constructor' on object instantiation |
| 13 |
## |
| 14 |
## Revision 1.4 2003/01/22 17:56:49 root |
| 15 |
## + fix: just use the logger if it's available |
| 16 |
## |
| 17 |
## Revision 1.3 2003/01/20 16:54:22 joko |
| 18 |
## + sub fromPackage: refactored from libp's 'getNewPerlObjFromPkgName' or s.th.l.th. |
| 19 |
## |
| 20 |
## Revision 1.2 2002/12/27 16:05:42 joko |
| 21 |
## + played with Devel::CallerItem and Devel::StackTrace |
| 22 |
## |
| 23 |
## Revision 1.1 2002/12/13 21:46:29 joko |
| 24 |
## + initial check-in |
| 25 |
## |
| 26 |
## --------------------------------------------------------------------------- |
| 27 |
|
| 28 |
|
| 29 |
package DesignPattern::Object; |
| 30 |
|
| 31 |
use strict; |
| 32 |
use warnings; |
| 33 |
|
| 34 |
|
| 35 |
use Data::Dumper; |
| 36 |
#use Devel::CallerItem; |
| 37 |
#use Devel::StackTrace; |
| 38 |
|
| 39 |
|
| 40 |
my $_dp_globals; |
| 41 |
|
| 42 |
$_dp_globals = { |
| 43 |
TRACE => 0, |
| 44 |
}; |
| 45 |
|
| 46 |
|
| 47 |
sub new { |
| 48 |
|
| 49 |
# the classname in most cases |
| 50 |
my $classname = shift; |
| 51 |
|
| 52 |
# use already blessed reference, if passed in - else use the very classname |
| 53 |
my $class = ref ($classname) || $classname; |
| 54 |
|
| 55 |
#$self->log_basic( "$classname->new( ... )" . "\t[via " . __PACKAGE__ . "]" , 'debug'); |
| 56 |
|
| 57 |
# the base for our object - a plain perl hash, which .... |
| 58 |
my $self = {}; |
| 59 |
# note: |
| 60 |
# this makes an instance of an arbitrary perl variable, |
| 61 |
# the most often used for this purpose is - guess it - the hash, |
| 62 |
# since it resembles object-properties in a convenient way: |
| 63 |
# $object->{property} = 'Hello World!'; |
| 64 |
# if you _do_ care about privacy you might take a look |
| 65 |
# at CPAN's Tie::SecureHash or Class::Contract ... have fun! |
| 66 |
|
| 67 |
# TODO: what about logging in here? inherit from |
| 68 |
# DesignPattern::Object::Logger for this purpose.... |
| 69 |
# ... or would this give us (harmful) circular module dependencies??? |
| 70 |
#$self->log_basic( __PACKAGE__ . "->new( @args )", 'debug' ); # this is not "common"! |
| 71 |
|
| 72 |
|
| 73 |
# remember the stacktrace: abstract this out (DesignPattern::Object::Trace) or parametrize! |
| 74 |
#my $trace = Devel::StackTrace->new(); |
| 75 |
#print Dumper($trace); |
| 76 |
#print Dumper($trace->frame(1)->args()); |
| 77 |
|
| 78 |
#print "args: ", $self->{'__caller'}->hasargs(), "\n"; |
| 79 |
|
| 80 |
#print Dumper($self); |
| 81 |
#exit; |
| 82 |
|
| 83 |
|
| 84 |
# argument-handling ... |
| 85 |
|
| 86 |
# ... get them ... |
| 87 |
my @args = (); |
| 88 |
@_ && (@args = @_); |
| 89 |
|
| 90 |
# ... check if we can coerce them into an array (this needs an even number of arguments) |
| 91 |
my $argcount = $#args + 1; |
| 92 |
my $fract = $argcount / 2; |
| 93 |
|
| 94 |
my $seperate = pop @args if $fract != int($fract); |
| 95 |
|
| 96 |
# mixin arguments |
| 97 |
$self = { @args }; |
| 98 |
|
| 99 |
# scan for arguments prefixed by a double underscore '__' |
| 100 |
foreach (keys %$self) { |
| 101 |
if (/^__(.+?)$/) { |
| 102 |
$self->{__bridge}->{$1} = $self->{$_}; |
| 103 |
delete $self->{$_}; |
| 104 |
} |
| 105 |
} |
| 106 |
|
| 107 |
# mixin seperate - FIXME: should this not be done after blessing? |
| 108 |
$self->{__bridge}->{'arg'} = $seperate if $seperate; |
| 109 |
|
| 110 |
# ... bless hash into object using classname |
| 111 |
bless $self, $class; |
| 112 |
|
| 113 |
# remember the caller |
| 114 |
$self->{__bridge}->{caller_module} = caller; |
| 115 |
#print Dumper(caller(2)); |
| 116 |
#exit; |
| 117 |
|
| 118 |
$self->{__bridge}->{class_name} = $classname; |
| 119 |
|
| 120 |
# patches for backward compatibility |
| 121 |
$self->{'__arg'} = $self->{__bridge}->{'arg'} if $self->{__bridge}->{'arg'}; |
| 122 |
$self->{'__caller'} = $self->{__bridge}->{caller_module} if $self->{__bridge}->{caller_module}; |
| 123 |
$self->{'__classname'} = $self->{__bridge}->{class_name} if $self->{__bridge}->{class_name}; |
| 124 |
|
| 125 |
$self->_init() if $self->can('_init'); |
| 126 |
$self->constructor() if $self->can('constructor'); |
| 127 |
|
| 128 |
# trace |
| 129 |
#print Dumper($self); |
| 130 |
#exit; |
| 131 |
|
| 132 |
return $self; |
| 133 |
} |
| 134 |
|
| 135 |
sub _abstract_function { |
| 136 |
my $self = shift; |
| 137 |
my $self_classname = ref $self; |
| 138 |
my $function_name = shift; |
| 139 |
# was: |
| 140 |
$self->log_basic( __PACKAGE__ . ": function '$function_name' is an abstract method, please implement it in '$self_classname'.", 'warning'); |
| 141 |
# is: |
| 142 |
#die( __PACKAGE__ . ": Function '$function_name' is an abstract method, please implement it in '$self_classname'."); |
| 143 |
#exit; |
| 144 |
} |
| 145 |
|
| 146 |
sub fromPackage { |
| 147 |
my $self = shift; |
| 148 |
#my $self_classname = ref $self; |
| 149 |
my $pkgname = shift; |
| 150 |
my @args = @_; |
| 151 |
# my $args = shift; |
| 152 |
|
| 153 |
# my $caller = $self->{'__caller'}; |
| 154 |
|
| 155 |
#print Dumper($args); |
| 156 |
|
| 157 |
$self->log_basic( __PACKAGE__ . "->fromPackage( pkgname $pkgname args @args )", 'debug'); |
| 158 |
|
| 159 |
# perl-load |
| 160 |
my $evstring = "use $pkgname;"; |
| 161 |
eval($evstring); |
| 162 |
|
| 163 |
# report errors |
| 164 |
if ($@) { |
| 165 |
# build error-messages |
| 166 |
my $issuer = __PACKAGE__ . ':' . __LINE__; |
| 167 |
my $errmsg_native = "Error in eval: " . $@; |
| 168 |
#my $classname = $self->{__classname}; |
| 169 |
my $errmsg_critical = ''; |
| 170 |
if ($errmsg_native =~ m/Can't locate (.+?) in \@INC/) { |
| 171 |
$errmsg_critical = "Could not instantiate object from package '$pkgname' ('$1' not found)."; |
| 172 |
} else { |
| 173 |
$errmsg_critical = $errmsg_native; |
| 174 |
} |
| 175 |
# write error to logging-output (console|file|database) |
| 176 |
$self->log_basic( $errmsg_native . " (issuer='$issuer', code='$evstring')", 'debug' ); |
| 177 |
$self->log_basic( $errmsg_critical, 'warning' ); |
| 178 |
return; |
| 179 |
} |
| 180 |
|
| 181 |
# object-creation |
| 182 |
my $object = $pkgname->new(@args); |
| 183 |
|
| 184 |
# run boot-methods on object |
| 185 |
$object->_init() if $object->can('_init'); |
| 186 |
$object->constructor() if $object->can('constructor'); |
| 187 |
|
| 188 |
return $object; |
| 189 |
} |
| 190 |
|
| 191 |
sub log_basic { |
| 192 |
my $self = shift; |
| 193 |
my $message = shift; |
| 194 |
my $level = shift; |
| 195 |
|
| 196 |
#return; |
| 197 |
$level ||= 'info'; |
| 198 |
|
| 199 |
if ($_dp_globals->{TRACE} || ($level && $level =~ /warning|error|critical/)) { |
| 200 |
print $level, ": ", $message, "\n"; |
| 201 |
} |
| 202 |
|
| 203 |
# get logger instance |
| 204 |
if (!$_dp_globals->{logger}) { |
| 205 |
$_dp_globals->{logger} = eval { Log::Dispatch::Config->instance; }; |
| 206 |
} |
| 207 |
|
| 208 |
if ($_dp_globals->{logger}) { |
| 209 |
$_dp_globals->{logger}->log( level => $level, message => $message); |
| 210 |
#} else { |
| 211 |
#print $level, ": ", $message, "\n"; |
| 212 |
} |
| 213 |
|
| 214 |
} |
| 215 |
|
| 216 |
1; |
| 217 |
__END__ |
Parent Directory
| 
Revision Log
