I'm wondering how integrations work with Backdrop. Is it the case, that it is possible to integrate with backdrop without any additional module in backdrop? The reason I think this might be the case is searching in the install modules page for civicrm comes back with modules that extend the integration but no base integration module.
I have a particular use case in mind, that of the open source Meeting Room Booking System (MRBS). I've used MRBS (https://mrbs.sourceforge.io/) a few times over the years. I'm currently implementing a gym booking system using it linked to the parent Joomla site. Many moons ago, MRBS had a Drupal module that allowed it to share logins (https://www.drupal.org/project/mrbs), but this was shut down as it was a security risk.
Currently, MRBS has the ability to authenticate using Joomla or Wordpress (amongst other methods). I think it could be a useful feather in Backdrop's cap if we could get an integration for authentication, and ideally email addresses/Display names.
I can't work out exactly how the Joomla integration works - all I did was created some roles in the main site, a link to the MRBS site and set the config to use Joomla authentication and recognise those role IDs and point to the Joomla base path.
I'm wondering if a Backdrop integration would be similar, mainly implemented in MRBS, but maybe some roles added? Is there a specific API that civiCRM uses to get the authentication from backdrop? Where could I look for this?
I think this could potentially be wider. If we can make it easy for other systems to integrate with Backdrop we create a stronger incentive for organisations to move.
My particular use cases I'm thinking of for MRBS is churches who nearly always need to have a way of booking resources. When the Drupal integration went, I had to switch to using the native db authentication with php sessions. However, when I started with this gym booking system on the Joomla site, it started me thinking that I would really like to get MRBS linking to Backdrop.
I tried to start a conversation on Zulip but it got no replies and dropped from the horizon. I thought by re-posting on the forum, it gives chance for a longer conversation and for any information to be available for longer.