NAME
Simo - Very simple framework for Object Oriented Perl.
VERSION
Version 0.05_06
FEATURES
Simo is framework that simplify Object Oriented Perl.
The feature is that
- 1. You can define accessors in very simple way.
- 2. Overridable new method is prepared.
- 3. You can define default value of attribute.
- 4. Simo is very small. so You can install and excute it very fast.
If you use Simo, you are free from bitter work writing new and accessors repeatedly.
SYNOPSIS
Define class and accessors.
package
Book;
use
Simo;
# define accessors
sub
title{ ac }
# define default value
sub
author{ ac
default
=>
'Kimoto'
}
# define constrain subroutine
sub
price{ ac
constrain
=>
sub
{ /^\d+$/ } }
# price must be integer.
# define filter subroutine
sub
description{ ac
filter
=>
sub
{
uc
} }
# convert to upper case.
# define trigger subroutine
sub
issue_datetime{ ac
trigger
=> \
&update_issue_date
}
sub
issue_date{ ac }
# if issue_datetime is updated, issue_date is updated.
sub
update_issue_date{
my
$self
=
shift
;
my
$date
=
substr
(
$self
->issue_datetime, 0, 10 );
$self
->issue_date(
$date
);
}
# read only accessor
sub
get_size{ ac
default
=> 5,
read_only
=> 1 }
1;
Using class and accessors
use
strict;
use
warnings;
use
Book;
# create object
my
$book
= Book->new(
title
=>
'OO tutorial'
);
# get attribute
my
$author
=
$book
->author;
# set attribute
$book
->author(
'Ken'
);
# constrain( If try to set illegal value, this call will die )
$book
->price(
'a'
);
# filter ( convert to 'IT IS USEFUL' )
$book
->description(
'It is useful'
);
# trigger( issue_date is updated '2009-01-01' )
$book
->issue_datetime(
'2009-01-01 12:33:45'
);
my
$issue_date
=
$book
->issue_date;
# read only accessor
$book
->get_size;
DESCRIPTION
Define class and accessors
You can define class and accessors in simple way.
new method is automatically created, and title accessor is defined.
Using class and accessors
You can pass key-value pairs to new, and can get and set value.
use
Book;
# create object
my
$book
= Book->new(
title
=>
'OO tutorial'
,
);
# get value
my
$title
=
$book
->title;
# set value
$book
->title(
'The simplest OO'
);
Automatically array convert
If you pass array to accessor, array convert to array ref.
$book
->title(
'a'
,
'b'
);
$book
->title;
# get [ 'a', 'b' ], not ( 'a', 'b' )
Accessor options
default option
You can define default value of attribute.
sub
title{ ac
default
=>
'Perl is very interesting'
}
constrain option
you can constrain setting value.
sub
price{ ac
constrain
=>
sub
{ /^\d+$/ } }
For example, If you call $book->price( 'a' ), this call is die, because 'a' is not number.
'a' is set to $_. so if you can use regular expression, omit $_.
you can write not omiting $_.
sub
price{ ac
constrain
=>
sub
{
$_
> 0 &&
$_
< 3 } }
If you display your message when program is die, you call craok.
use
Carp;
sub
price{ ac
constrain
=>
sub
{
$_
> 0 &&
$_
< 3 or croak
"Illegal value"
} }
and 'a' is alse set to first argument. So you can receive 'a' as first argument.
sub
price{ ac
constrain
=> \
&_is_number
}
sub
_is_number{
my
$val
=
shift
;
return
$val
=~ /^\d+$/;
}
and you can define more than one constrain.
sub
price{ ac
constrain
=> [ \
&_is_number
, \
&_is_non_zero
] }
filter option
you can filter setting value.
sub
description{ ac
filter
=>
sub
{
uc
} }
setting value is $_ and frist argument like constrain.
and you can define more than one filter.
sub
description{ ac
filter
=> [ \
&uc
, \
&quoute
] }
trigger option
You can define subroutine called after value is set.
For example, issue_datetime is set, issue_date is update.
$self is set to $_ and $_[0] different from constrain and filter.
sub
issue_datetime{ ac
trigger
=> \
&update_issue_date
}
sub
issue_date{ ac }
sub
update_issue_date{
my
$self
=
shift
;
my
$date
=
substr
(
$self
->issue_datetime, 0, 10 );
$self
->issue_date(
$date
);
}
and you can define more than one trigger.
sub
issue_datetime{ ac
trigger
=> [ \
&update_issue_date
, \
&update_issue_time
] }
read_only option
Read only accessor is defined
sub
get_size{ ac
default
=> 5,
read_only
=> 1 }
Accessor name should be contain 'get_'.If not, warnings is happen.
hash_force option
If you pass array to accessor, Normally list convert to array ref. $book->title( 'a' , 'b' ); # convert to [ 'a', 'b' ]
Even if you write $book->title( a => 'b' )
( a => 'b' ) converted to [ 'a', 'b' ]
If you use hash_force option, you convert list to hash ref
sub
country_id{ ac
hash_force
=> 1 }
$book
->title(
a
=>
'b'
);
# convert to { a => 'b' }
set_hook option
set_hook option is now not recommended. this option will be deleted in future 2019/01/01
get_hook option
get_hook option is now not recommended. this option will be deleted in future 2019/01/01
Order of constrain, filter and trigger
- 1. val is passed to constrain subroutine.
- 2. val is passed to filter subroutine.
- 3. val is set
- 4. trigger subroutine is called
|---------| |------| |-------|
| | | | | |
val-->|constrain|-->|filter|-->(val is set)-->|trigger|
| | | | | |
|---------| |------| |-------|
Get old value
You can get old value when you use accessor as setter.
$book
->author(
'Ken'
);
my
$old_value
=
$book
->author(
'Taro'
);
# $old_value is 'Ken'
FUNCTIONS
ac
ac is exported. This is used by define accessor.
new
orveridable new method.
MORE TECHNIQUES
I teach you useful techniques.
New method overriding
by default, new method receive key-value pairs. But you can change this action by overriding new method.
For example, Point class. You want to call new method this way.
my
$point
= Point->new( 3, 5 );
# xPos and yPos
You can override new method.
Simo implement inheritable new method. Whenever You change argments or add initializetion, You override new method.
Extend base class
you may want to extend base class. It is OK.
But I should say to you that there are one thing you should know. The order of Inheritance is very important.
I write good sample and bad sample.
If you call new method in Good sample, you call Book::new method. This is what you wanto to do.
If you call new method in Bad sample, you call Simo::new method. you will think why Book::new method is not called?
Maybe, You will be wrong sometime. So I recomend you the following writing.
It is like other language class Definition and I think looking is not bat. and you are not likely to choose wrong order.
CAUTION
set_hook and get_hook option is now not recomended. these option will be deleted in future 2019/01/01
and non named defalut value definition is not recommended. this expression cannot be available in future 2019/01/01
sub
title{ ac
'OO tutorial'
}
# not recommend. cannot be available in future.
AUTHOR
Yuki Kimoto, <kimoto.yuki at gmail.com>
BUGS
Please report any bugs or feature requests to bug-simo at rt.cpan.org
, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Simo. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.
SUPPORT
You can find documentation for this module with the perldoc command.
perldoc Simo
You can also look for information at:
RT: CPAN's request tracker
AnnoCPAN: Annotated CPAN documentation
CPAN Ratings
Search CPAN
SEE ALSO
Class::Accessor,Class::Accessor::Fast, Moose, Mouse.
COPYRIGHT & LICENSE
Copyright 2008 Yuki Kimoto, all rights reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.