NAME¶
Rose::DB::Object::MakeMethods::Std - Create object methods related to
Rose::DB::Object::Std-derived objects.
SYNOPSIS¶
package Category;
our @ISA = qw(Rose::DB::Object::Std);
...
package Color;
our @ISA = qw(Rose::DB::Object::Std);
...
package Product;
our @ISA = qw(Rose::DB::Object);
...
use Rose::DB::Object::MakeMethods::Std
(
object_by_id =>
[
color => { class => 'Color' },
category =>
{
class => 'Category',
id_method => 'cat_id',
share_db => 0,
},
],
);
...
$prod = Product->new(...);
$color = $prod->color;
# $prod->color call is roughly equivalent to:
#
# $color = Color->new(id => $prod->color_id,
# db => $prod->db);
# $ret = $color->load;
# return $ret unless($ret);
# return $color;
$cat = $prod->category;
# $prod->category call is roughly equivalent to:
#
# $cat = Category->new(id => $prod->cat_id);
# $ret = $cat->load;
# return $ret unless($ret);
# return $cat;
DESCRIPTION¶
"Rose::DB::Object::MakeMethods::Std" creates methods related to
Rose::DB::Object::Std-derived objects. It inherits from
Rose::Object::MakeMethods. See the Rose::Object::MakeMethods documentation to
learn about the interface. The method types provided by this module are
described below.
All method types defined by this module are designed to work with objects that
are subclasses of (or otherwise conform to the interface of) Rose::DB::Object.
In particular, the object is expected to have a "db" method that
returns a Rose::DB-derived object. See the Rose::DB::Object::Std documentation
for more details.
METHODS TYPES¶
- object_by_id
- Create a get/set methods for a single
Rose::DB::Object::Std-derived object loaded based on a primary key stored
in an attribute of the current object.
- Options
- "class"
- The name of the Rose::DB::Object::Std-derived class of the
object to be loaded. This option is required.
- "hash_key"
- The key inside the hash-based object to use for the storage
of the object. Defaults to the name of the method.
- "id_method"
- The name of the method that contains the primary key of the
object to be loaded. Defaults to the method name concatenated with
"_id".
- "interface"
- Choose the interface. The only current interface is
"get_set", which is the default.
- "share_db"
- If true, the "db" attribute of the current object
is shared with the object loaded. Defaults to true.
- Interfaces
- "get_set"
- Creates a method that will attempt to create and load a
Rose::DB::Object::Std-derived object based on a primary key stored in an
attribute of the current object.
If passed a single argument of undef, the "hash_key" used to store
the object is set to undef. Otherwise, the argument is assumed to be an
object of type "class" and is assigned to "hash_key"
after having its primary key set to the corresponding value in the current
object.
If called with no arguments and the "hash_key" used to store the
object is defined, the object is returned. Otherwise, the object is
created and loaded.
The load may fail for several reasons. The load will not even be attempted
if the primary key attribute in the current object is undefined. Instead,
undef will be returned. If the call to the newly created object's
"load" method returns false, that false value is returned.
If the load succeeds, the object is returned.
Example:
package Category;
our @ISA = qw(Rose::DB::Object::Std);
...
package Color;
our @ISA = qw(Rose::DB::Object::Std);
...
package Product;
our @ISA = qw(Rose::DB::Object);
...
use Rose::DB::Object::MakeMethods::Std
(
object_by_id =>
[
color => { class => 'Color' },
category =>
{
class => 'Category',
id_method => 'cat_id',
share_db => 0,
},
],
);
...
$prod = Product->new(...);
$color = $prod->color;
# $prod->color call is roughly equivalent to:
#
# $color = Color->new(id => $prod->color_id,
# db => $prod->db);
# $ret = $color->load;
# return $ret unless($ret);
# return $color;
$cat = $prod->category;
# $prod->category call is roughly equivalent to:
#
# $cat = Category->new(id => $prod->cat_id);
# $ret = $cat->load;
# return $ret unless($ret);
# return $cat;
AUTHOR¶
John C. Siracusa (siracusa@gmail.com)
LICENSE¶
Copyright (c) 2010 by John C. Siracusa. All rights reserved. This program is
free software; you can redistribute it and/or modify it under the same terms
as Perl itself.