How can i render a file using a formatter programmatically in a controller?

I'm trying to create a controller to render a swagger documentation using the module swagger_ui_formatter that provide a formatter to the file field that render swagger files (yml, yaml, json) using javascript libraries to show the documentation like swagger website do. Then i copy my yml file in my module directory and in my controller i can load this file.

  public function buildApiDocumentation() {

    $file_system = \Drupal::service('file_system');

    $searchFiles = '/^.*\.(yml)$/';
    $directory = dirname(__DIR__,2).'/docs';

    $file = $file_system->scanDirectory($directory, $searchFiles, ['recurse' => FALSE]);
}

But i don't know how can i render this file using the swagger formatter that the module provide, i can't use the traditional way to use this formatter, creating a content type with a file field and after that create a view and render it, because is a very manual process and i need to fix the api documentation file in a directory that only the dev team can update.

as @apaderno mentioned we can't use a formatter that way, then i decided to build my own module to render my swagger documentation using the official swagger ui, and load the file using a javascript directive.

Thanks for helping.

You can return a BinaryFileRespose from your controller:

use Symfony\Component\HttpFoundation\BinaryFileResponse;

public function buildApiDocumentation() {

  $file_system = \Drupal::service('file_system');

  $searchFiles = '/^.*\.(yml)$/';
  $directory = dirname(__DIR__,2).'/docs';

  $file = $file_system->scanDirectory($directory, $searchFiles, ['recurse' => FALSE]);

  return new BinaryFileResponse($file);
}