Dependency Injection in CakePHP

This plugin based on Symfony2 component DependencyInjection. More about DI you may find in this articles: Martin Fowler "Inversion of Control Containers and the Dependency Injection pattern" and Fabien Potencier "What is Dependency Injection?"

Requirements:

1. PHP version 5.3.2 or greater
2. CakePHP version 1.3.x
3. Plugin folder name should be dependency_injection

Installation:

Clone from git:

cd app/plugins
git clone git://github.com/mind-blowing/cakephp-dependency-injection.git dependency_injection

cd dependency_injection
git submodule init
git submodule update

Init class loader:

For this plugin you need use class loader, for make your life easier I create class loader for this plugin. For init plugin class loader you need add this code to app/config/bootstrap.php:

App::import('libs', 'DependencyInjection.ClassLoader', array('file' => 'ClassLoader.php'));

\dependency_injection\libs\ClassLoader::register();

Configuration:

You may configure this plugin. Configuration params need be placed at app/config folder in di.yml or di.ini file, depending on what file format you want to chose.

Available params:

cache_config_name: string default(default) - This parameter for set what cache config will be used to cache.
cache_container_key: string default(diPluginContainer) - This parameter for set what cache key will be used to cache container.
use_cache: boolean default(false) - This parameter for set cache use.
app_config_file_name: string default(di_services) - This parameter for set what file name will be used for application service configuration.
plugin_config_file_name: string default(di_plugin_config) - This parameter for set what file name will be used for store plugins configurations.

####Example yaml:

# app/config/di.yml

use_cache: true
app_config_file_name: services

####Example ini:

# app/config/di.ini

use_cache = true
cache_config_name = memcacheStorage

Cache:

For best speed result I recommend use cache, but by default cache is disabled in this plugin. To enable cache you need set use_cache param to true in configuration. More information in previous section.

Application configuration:

Xml application service configuration you need place to app/config/di_services.xml, example:

<services>
    <service id="service_name" class="ClassName">
        <argument>example</argument>
    </service>
</services>

More xml examples you can find here Container configuration examples.

Yaml application service configuration you need place to app/config/di_services.yml, example:

services:
    service_name:
        class:        ClassName
        arguments:    [example]

More yaml examples you can find here Container configuration examples.

Plugins configuration:

DI plugin may load plugin services automaticly and you may configurate plugin services without change it source code, this process can be divided into several steps:

Create Extension class in your plugin:

<?php

// app/plugins/example_plugin/DependencyInjection/Extension.php

namespace example_plugin\DependencyInjection;

use \dependency_injection\DependencyInjection\BaseExtension;
use \Symfony\Component\DependencyInjection\ContainerBuilder;

class Extension extends BaseExtension
{
    function load(array $config, ContainerBuilder $container)
    {
        // TODO: Implement load() method.
    }

    function getAlias()
    {
        return 'example_plugin';
    }
}

More info about how to create Extension class in plugin you can find here Extension class in plugin.

Configure plugins in application: allow only in yaml format, for this you need put all in app/config/di_plugin_config.yml:

In this example you will see how set custom Extension class name and set path from where it will be included(with require_once function), by default class will loaded using your autoload system, and full class name will be generated with namespace by this rule: \$pluginName\DependencyInjection\Extension

example_plugin:
    options:
        class_name: ExtensionClassName
        class_path: "<?php echo APP . 'plugins' . DS . 'example_plugin' . DS . 'DependencyInjection' . DS . 'ExtensionClassName.php'; ?>"
    config:
        param: example
        param_collection:
            - one
            - two

Example without any settings (will be used \example_plugin\DependencyInjection\Extension class):

example_plugin:
    config: ~

Get container in controller:

For use DI in controller you need inject DI container. You need implement ContainerAwareInterface in class and add component DependencyInjection.Container, example:

use \Symfony\Component\DependencyInjection\ContainerAwareInterface;
use \Symfony\Component\DependencyInjection\ContainerInterface;

class ExampleController extends AppController implements ContainerAwareInterface
{
    public $components = array('DependencyInjection.Container');

    private $container;

    public function setContainer(ContainerInterface $container = null)
    {
        $this->container = $container;
    }

Get container in model:

For use DI in model you need inject DI container. You need implement ContainerAwareInterface in class and add behavior DependencyInjection.Container, example:

use \Symfony\Component\DependencyInjection\ContainerAwareInterface;
use \Symfony\Component\DependencyInjection\ContainerInterface;

class Example extends AppModel implements ContainerAwareInterface
{
    public $actsAs = array('DependencyInjection.Container');

    private $container;

    public function setContainer(ContainerInterface $container = null)
    {
        $this->container = $container;
    }

More documentation:

More documentation you can find in doc folder or here Documentation.