Plugin dev with Sendinblue mailer integration I am trying to integrate with sendinblue API and I installed it with composer as a third party library.
But it still does not work:
Fatal error: Class 'Mailin' not found in /localfolder/www/craft/plugins/stepsprogram/controllers/StepsProgramController.php on line 225

Here is the composer.json file at the root of my plugin:

{
    "name": "/stepsprogram",
    "description": "Steps Program.",
    "type": "craft-plugin",
    "require": {
        "composer/installers": "~1.0",
        "mailin-api/mailin-api-php": "^1.0"
    }
}


The init function of my plugin: 

public function init()
{
    // If using composer
    require_once __DIR__ . '/vendor/autoload.php';
}


And the error happen here when trying to call the mailin class in my controller:  

        $mailin = new \Mailin('https://api.sendinblue.com/v2.0', 'dqsdsapicode', 5000);    //Optional parameter: Timeout in MS
        var_dump($mailin-&gt;get_account());
Looks like you're missing the proper namespace.

Should be:

$mailin = new \Sendinblue\Mailin('https://api.sendinblue.com/v2.0', 'dqsdsapicode', 5000);


And here also is the other syntax for a global call in the controller.
Controller beginning would be:

&lt;?php
namespace Craft;

use Sendinblue\Mailin;

class FooController extends BaseController


Then class call will be:

$mailin = new Mailin('https://api.sendinblue.com/v2.0', 'dqsdsapicode', 5000);