Hi Monks,
I am confused in the Perl object serialization (or serialization in general) topic. Please shed some light and enlighten me.
I understand that perl serialization (using Storable module for example) can perfectly do the object / variables-value serialization. This means that, if I serialize a Moose class (ofcourse object), all the properties / variable values will be saved in a file and I can get them later to reconstruct the Moose object.
I also understand that, the code part (Subs) can not be / will not be by default serialized. When we talk about Object Oriented Programming, The object contains two parts
- Data
- Procedure / function to operate on the Data
I thought only Data part will be serialized. But I am wrong, To illustrate my confusion, Please see my example code below,
package MooseClass;
#MooseClass.pm file
use strict;
use warnings;
use Moose;
use namespace::autoclean;
#--------ONLY for Eclipse ----
#Just for the Perl Eclipse IDE to auto complete $self variable
#$self = MooseClass->new();
#--------ONLY for Eclipse ----
# Members
has 'name',is=>'rw',isa=>'Str',required=>1;
has 'age',is=>'rw',isa=>'Int',required=>1;
has 'gender', is=>'rw', isa=>'Str', required=>0;
sub BUILD
{
my $self = shift @_;
my $constArgsHashRef = shift @_; # Hash ref of arguments passed to
+ constructor at the time of object creation
return 1;
}
sub increaseAge
{
my $self = shift @_;
$self->age($self->age()+1);
print "\n ", $self->name(), " is now ",$self->age()," old. ";
return 1;
}
sub getAgeIterator
{
my $self = shift @_;
my $iter = sub
{
print "\n iterate to next age", " AgeNow: ",$
+self->age();
return $self->age($self->age()+1);
};
return $iter;
}
#Do it for all classes so Moose will create fast object creation, so a
+pplication runs faster
__PACKAGE__->meta->make_immutable();
no Moose;
1;
#serialize.pl
use strict;
use warnings;
use Storable;
use MooseClass;
use Data::Dumper;
my $obj = MooseClass->new(name=>'Eva',age=>'20',gender=>'girl');
print "\n Class dump \n", Dumper($obj);
$obj->increaseAge();
print "\n Class dump 2\n", Dumper($obj);
my $nextage = $obj->getAgeIterator();
$nextage->();
$nextage->();
print "\n Class dump 3\n", Dumper($obj);
#Lets serailize the $obj
store ($obj,'serialize.bin');
#Lets deserialize the object
#--------ONLY for Eclipse ----
#Just for the Perl Eclipse IDE to auto complete $self variable
#$newObj = MooseClass->new();
#--------ONLY for Eclipse ----
my $newObj = retrieve ('serialize.bin');
print "\n \n New Class dump1 \n", Dumper($newObj);
$newObj->increaseAge();
print "\n \n New Class dump2 \n", Dumper($newObj);
my $newnextAge = $newObj->getAgeIterator();
$newnextAge->();
$newnextAge->();
print "\n \n New Class dump3 \n", Dumper($newObj);
#Output
Class dump
$VAR1 = bless( {
'name' => 'Eva',
'age' => '20',
'gender' => 'girl'
}, 'MooseClass' );
Eva is now 21 old.
Class dump 2
$VAR1 = bless( {
'name' => 'Eva',
'age' => 21,
'gender' => 'girl'
}, 'MooseClass' );
iterate to next age AgeNow: 21
iterate to next age AgeNow: 22
Class dump 3
$VAR1 = bless( {
'name' => 'Eva',
'age' => 23,
'gender' => 'girl'
}, 'MooseClass' );
New Class dump1
$VAR1 = bless( {
'gender' => 'girl',
'age' => 23,
'name' => 'Eva'
}, 'MooseClass' );
Eva is now 24 old.
New Class dump2
$VAR1 = bless( {
'gender' => 'girl',
'age' => 24,
'name' => 'Eva'
}, 'MooseClass' );
iterate to next age AgeNow: 24
iterate to next age AgeNow: 25
New Class dump3
$VAR1 = bless( {
'gender' => 'girl',
'age' => 26,
'name' => 'Eva'
}, 'MooseClass' );
I thought $newObj (which is de-serialized), Can not call the class methods (Closure also working !). How its possible? This means, I can send this object to some other perl script / process which does not "use" the MooseClass and can it operate on the class member functions? So the serialization by default embeds the moose class member function code as well?
forgive me, If I miss the obvious.
