And I understand your point of view.
But if you take a look at the content plugin (and I guess you will if you want to extend jBackend with your plugins) you will then figure out why the categories are restricted to com_content only.
Each plugin is written to "mimic" the behavior of the original extension, so the snippet to retrieve categories is almost the same used by Joomla and based on this principle:
$categories = JCategories::getInstance('Content', $options);
In this way I can deal with tree and nested categories and ACL just exploiting the original code. This is the trend for all existing plugins (first I trace the original extension code, then I replicate to produce json responses).
And the original Joomla code doesn't allow to get non-content categories, so this is the reason I should add a new snippet in the content plugin or (at this point better for isolation) a new different plugin.
So if you need help to extend features just let me know.
Kind regards,
Luigi
