Re: Extending Groups
Why would you use wp_sitemeta to store data about a group? Doesn’t really make sense to me. This table is for storing data about your site, not about a group. Also, this table doesn’t exist in a single WP install, so it’d be kinda counter-productive. If you need to store data about a group, then store it in the proper table, which is wp_bp_groups_groupmeta.
As for metadata tables vs creating your own plugin tables, it just depends on what your needs are. Metadata tables are fine for kinda static, small pieces of data, while you would use a custom table for data that grows with time.
A plugin that modifies or adds to group functionality will most likely utilize the groups API. This is suitable for adding more complex functionality. More basic functionality can be added by using the various action calls you can find in the template files. Again, it really depends on what you’re trying to achieve.