How can I create a very simple entity definition for Webform submissions? I make extensive use of the Webform module and often use Views for managing the webform submissions.

I'm fairly new to the Actions/Rules/Triggers backend of Views Bulk Operations (VBO), but I'd really like to be able to use it in my submission management views.

I've written a module that accepts submission IDs from the URL like so: mymodule/form/314/submissions/201+202+203 and generates a page with information from all the listed submissions (in this case, submissions 201, 202, and 203). 

I want to use the VBO "Pass ids as arguments to a page" operation to select submissions in a my Views table, and pass their IDs to my custom page.

As far as I can tell, this isn't possible since webform submissions are not entities. So what I'm wondering is, how can I define a very simple entity type for webform submissions, so that I can use VBO on them?

I assume I should implement hook_entity_info(). I think the entity really only needs to include the submission ID in my case (the sid column in the webform_submissions db table).

I've read through the docs on defining custom entities, but can't figure out how to apply that stuff where I'm not actually wanting to create an entity type from scratch. Thanks!
Got it working. In a custom module (mymodule), I implemented hook_entity_info() like so:

function mymodule_entity_info() {
  $info = array();
  $info['mm_submission'] = array(
    'label' =&gt; t('Simple Webform Submission Entity'),
    'base table' =&gt; 'webform_submissions',
    'fieldable' =&gt; FALSE,
    'entity keys' =&gt; array(
      'id' =&gt; 'sid',
      'label' =&gt; 'sid',
    ),
  );
  return $info;
}


This very simple entity definition was sufficient for VBO to treat my submissions as entities and pass their IDs to my custom URL.

Though I didn't need to, it should be possible to override the entity class controller and its entity functions (load, save, delete, etc) should you need to. This tutorial by Ronald Ashri was useful to me and talks more about that. 

After installing my custom module, I was pleasantly surprised to see a "Bulk operations: Webform submissions" field magically appear in the list of available Views fields.

I didn't make any other connection between Webform submissions and my custom entity type, nor otherwise tell VBO to treat the Views results as mm_submission entities--somebody (Views/VBO/Webform?) just automatically made it happen; which is awesome.

I presume VBO knew to process the submissions as mm_submission entities because of the entity type base table attribute? Not sure without looking more closely; perhaps someone else can shed more light on that.