EagerLoader Plugin for CakePHP 2.x

An eager loading beahavior plugin for CakePHP 2.x which is highly compatible to the Containable behavior but generates better queries.

Requirements

• CakePHP 2.x
• PHP 5.3+

Installation

See the How to Install Plugins in the CakePHP documentation for general help.

• Put the EagerLoader directory into your plugin directory or install the plugin with Composer from the directory where your composer.json file is located:

php composer.phar require chinpei215/cakephp-eager-loader

• Load the plugin in your app/Config/bootstrap.php file:

CakePlugin::load('EagerLoader');

• And enable the behavior in your models or in your app/Model/AppModel.php:

class Post extends AppModel {
    public $actsAs = array('EagerLoader.EagerLoader');
}

Usage

$Comment->find('first', [
	'contain' => [
		'Article.User.Profile',
		'User.Profile',
	]
]);

EagerLoaderBehavior has a high compatibility with ContainableBehavior, but generates better queries. In the above example, only 2 queries will be executed such as the following:

SELECT
	Comment.id, ...
FROM
	comments AS Comment
	LEFT JOIN articles AS Article ON (Comment.article_id = Article.id)
	LEFT JOIN users AS User ON (Article.user_id = User.id)
	LEFT JOIN profiles AS Profile ON (User.id = Profile.user_id)
WHERE
	1 = 1

SELECT
	User.id, ...
FROM
	users AS User
	LEFT JOIN profiles AS Profile ON (User.id = Profile.user_id)
WHERE
	User.id IN (1, 2, 3)

If using ContainableBehavior, how many queries are executed? 10 or more?

Incompatibility problems

EagerLoaderBehavior returns almost same results as ContainableBehavior, however you might encounter incompatibility problems between the 2 behaviors. For example EagerLoaderBehavior::contain() is not implemented yet.

Then disabling EagerLoaderBehavior on the fly, you can use ContainableBehavior::contain() instead:

$Comment->Behaviors->disable('EagerLoader');
$Comment->Behaviors->load('Containable');
$Comment->contain('Article');
$result = $Comment->find('first');

For your information, EagerLoaderBehavior can be coexistent with ContainableBehavior.

$actsAs = [
	'EagerLoader.EagerLoader', // Requires higher priority than Containable
	'Containable'
]

Using this way, you need not to call load('Containable') in the above example.