How create Group Blogs based on user created Groups

Question

I'm looking to create a site that allows registered users to create their own groups and have their own group blogs. They should be able to have a group page with a few details about the group and it should show the group blog. I've thought of a couple of ways of doing this but both seem to require custom plugins.

1) Use the BuddyPress plugin. This gives the groups but there currently is no BP plugin that allows group blogs.

2) Use categories. This gives the group blog if categories are set with permissions as to who can post using them and if each blog post can only have one category. Would need to create a plugin that allows users to create a new category and have that as the 'group'. The plugin would also need to allow group members to be invited.

Is there another way to achieve this is WordPress? Any help would be greatly appreciated.

Note: I don't want to use WordPress MU.

Answer 1

Use a multisite. There are no good reasons not to do that. For the groups I would use two custom tables:

1. A group table for the description, maybe an image path/ID an a group ID. You could also use a custom post type on the main site for that, but it is easier to optimize the queries for a custom table.
2. A group_users table to associate user IDs with group IDs. You could the usermeta table, but again – performance.

Whenever a user creates a group, create a new blog. WordPress has internal routines for that, it will set up all the necessary tables for you, and you can even control the plugins and the theme that are active or available for that blog.

I would use the main site just to list the blogs.