How to create a form, using a function, located inside a class Usually when we need to create a form we create a function inside module and call:

$form = drupal_get_form('function_name');
drupal_render($form);


Now I started using entities and created a subclass of EntityDefaultUIController. With a form generating function:

class transactionUIController extends EntityDefaultUIController {
  public function overviewForm($form, &amp;$form_state) {
     //blah blah
     return $form;
  }
}


I need to get this from in an external module. What should I pass to drupal_get_form function?
You can use the form callbacks provided by the entity module. So for your example (assuming your entity_type is named 'transaction') you would call drupal_get_form like so:

drupal_get_form('entity_ui_overview_form', 'transaction');


You can find other Entity UI form related functions here.