Symfony2 seems not capable to parse Angular $http data. This class overrides default SF2 Request to parse request body sent by Angular then put data in query field.

AngularRequest.php

class AngularRequest extends \Symfony\Component\HttpFoundation\Request
{
    /**
     * Creates a new request with values from PHP's super globals.
     *
     * @return Request A new request
     *
     * @api
     */
    public static function createFromGlobals()
    {
        $request = parent::createFromGlobals();

        $requestBody = $request->getContent();

        if (!empty($requestBody))
        {
            $requestBodyData = json_decode($requestBody, true);

            if (!empty($requestBodyData) && is_array($requestBodyData))
            {
                $request->query->add($requestBodyData);
            }
        }

        return $request;
    }
}