Auryn example

//First we setup some aliasing of interfaces to concrete classes
$provider->alias('Intahwebz\Storage\Storage', 'Intahwebz\Storage\S3Storage');
$provider->alias('Intahwebz\DB\DBConnection', 'Intahwebz\DB\ProxiedConnectionWrapper');
//So any dependency on a 'Storage' interface will now have an S3Storage ojbect provided.


$standardLogger = createStandardLogger();
$provider->alias('Psr\Log\LoggerInterface', 'Monolog\Logger');
$provider->share($standardLogger); //Used by all classes
//Now any request for a PSR0 LoggerInterface will be given the '$standardLogger' object.





//Ok, this is the Controller for a page that grabs images from other websites.

class ImageFetcher extends \Intahwebz\Controller\Controller {

 function __construct(Storage $storage, ImageMapper $imageMapper, RemoteFileFetcher $remoteFileFetcher) {
        $this->storage = $storage;
        $this->imageMapper = $imageMapper;
        $this->remoteFileFetcher = $remoteFileFetcher;
    }
}

//To instantiate it, I call:
$provider->make('ImageFetcher');

//And that's it.
//
//All the dependencies of that class are recursively created.
//
//The dependencies of that controller class are listed below, there is actually quite a bit of work to
//instantiate the controller class but it's all handled by Auryn.



class RemoteFileFetcher {} //No dependencies

abstract class Storage {}

class S3Storage extends Storage {
    function __construct(
        LoggerInterface $logger,
        StoragePath $storagePath) {
    }
}


class ImageMapper {
  function __construct(
        SQLQueryFactory $sqlQueryFactory,
        ContentTable $contentTable,
        ImageTable $imageTable,
        TagTable $tagTable,
        ContentBucketTable $contentBucketTable) {}
}




class SQLQueryFactory {
    //Yeah, this is kind of a factory, but it's simple enough to not be
    //a bad thing to do.
    public function __construct(DBConnection $dbConnection) {
        $this->dbConnection = $dbConnection;
    }
    function create() {
        return new SQLQuery($this->dbConnection);
    }
}

class ContentTable extends SQLTableMap {
   //My crappy DB abstraction layer.
   function __construct(DBConnection $dbConnection){}
}