Zend Framework 2 : Getting Closer with PluginManager

In ZF2, there is PluginManager that we can use to collect services with same contract interfaces or ancestor class into single class properties. After that, we can validate whenever the plugins as services are instance of that interfaces or ancestor class ( usually an abstract class ). There are properties of PluginManager class that can collect the services :
1. $factories
2. $invokableClasses
3. $aliases(aliasing registered services at $factories or $invokableClasses)
The basic class structure of PluginManager is like this :

namespace YourModule;

use Zend\ServiceManager\AbstractPluginManager;

class PluginManager extends AbstractPluginManager
{
    protected $factories = array(
        //represent factories key
    );
    
    protected $invokableClasses = array(
        //represent invokables key
    );
    
    protected $aliases = array(
        //represent aliases key
    );
    
    public function validatePlugin($plugin)
    {
        if ($plugin instanceof Plugin\PluginInterface) {
            // we're okay
            return;
        }
        
        throw new \InvalidArgumentException(sprintf(
            'Plugin of type %s is invalid; must implement %s\Plugin\PluginInterface',
            (is_object($plugin) ? get_class($plugin) : gettype($plugin)),
            __NAMESPACE__
        ));
    }
}

For example, you need to create collection of services that can convert content into another format, for example, you want to create services that can convert to ‘xls’, ‘pdf’, or other. so you can create pluginmanager to collect that services, like the following :

Let’s code!
1. create the ConverterContentPluginManager PluginManager

//filename : module/Tutorial/src/Tutorial/ConverterContentPluginManager.php
namespace Tutorial;

use Zend\ServiceManager\AbstractPluginManager;

class ConverterContentPluginManager extends AbstractPluginManager
{
    protected $invokableClasses = array(
        //represent invokables key
        'xls' => 'Tutorial\Plugin\Xls',
        'pdf' => 'Tutorial\Plugin\Pdf'
    );

    public function validatePlugin($plugin)
    {
        if ($plugin instanceof Plugin\PluginInterface) {
            // we're okay
            return;
        }

        throw new \InvalidArgumentException(sprintf(
            'Plugin of type %s is invalid; must implement %s\Plugin\PluginInterface',
            (is_object($plugin) ? get_class($plugin) : gettype($plugin)),
            __NAMESPACE__
        ));
    }
}

2. Create the plugin interface to be implemented

//filename : module/Tutorial/src/Tutorial/Plugin/PluginInterface.php
namespace Tutorial\Plugin;

interface PluginInterface
{
    public function convert($content);
}

3. Create that services
a. the Xls service

//filename : module/Tutorial/src/Tutorial/Plugin/Xls.php
namespace Tutorial\Plugin;

class Xls implements PluginInterface
{   
    public function convert($content)
    {
        echo 'xls convert here';
        //implementation of convert $content to convert content into xls
    }
}

b. the Pdf service

//filename : module/Tutorial/src/Tutorial/Plugin/Pdf.php
namespace Tutorial\Plugin;

class Pdf implements PluginInterface
{   
    public function convert($content)
    {
        echo 'pdf convert here';
        //implementation of convert $content to convert content into pdf
    }
}

4. Create a factory class for the ConverterContentPluginManager

//filename : module/Tutorial/src/Tutorial/Service/ConverterContentPluginManagerFactory.php
namespace Tutorial\Service;

use Zend\Mvc\Service\AbstractPluginManagerFactory;

class ConverterContentPluginManagerFactory extends AbstractPluginManagerFactory
{
    const PLUGIN_MANAGER_CLASS = 'Tutorial\ConverterContentPluginManager';
}

5. Last step, register into service manager ( just one service, the ConverterContentPluginManagerFactory one )

//filename : module/Tutorial/config/module.config.php
return array(
    'service_manager' => array(
        'factories' => array(
            'convertercontent' => 'Tutorial\Service\ConverterContentPluginManagerFactory'  
        ),
    ),
);

Ok, now you can grab the plugins via :

$content = 'sample content you want to convert';
$converter = $this->getServiceLocator()->get('convertercontent')
$converter->get('xls')->convert($content);
$converter->get('pdf')->convert($content);

Done😉

References :
1. http://raing3.gshi.org/2013/05/26/creating-custom-plugin-manager-in-zend-framework-2/
2. http://zf2.readthedocs.org/en/latest/modules/zend.mvc.services.html