Component

register components in configs.php

return [
    'components' => [
        'mongo' => 'Mongo', [
            'collections' => [
                'users','posts' => [
                    'url'        => 'mongodb://localhost:27017',
                    'database'   => 'project',
            ],
        ],
        'redis' => 'Redis', [
            'dbs' => [
                'default' => [
                    'host'     => 'localhost',
                    'pconnect' => true,
                ],
            ],
        ],
    ],
];

accessing components

$app->mongo->users->findOne();

register componets on the fly

$app->register('db', '\ns\SomeDB', ['host' => $host, 'port' => $port]);

or using a closure

$app->register('myComponent', function(){
    return new \ns\SomeComponent();
});

execute some additional code when the component is actually initialized

$app->register('db', '\ns\SomeDB', ['url' => $url])->initialized(function($db) {
    $connected = $db->connect();
});

component depends on other components

return [
    'components' => [
        'httpclient' => '\HTTPClient',
        'restclient' => '\RestClient' => [
            'baseurl' => 'http://restserver.io'
        ],
    ],
];

class RestClient
{
    function __construct($baseurl, $httpclient)
    {
        // $httpclient is an instance of \HTTPClient;
    }
}