When I first started using WPMU, the now-integrated multisite version of WordPress, I found it strange that there were no built-in tools to aggregate content onto the main blog. It seemed to me that that was something plenty of people would want to do. Sure, there were plugins and hacks, but none of them were as polished as I’d like them to be.
Fortunately, things have changed. WordPress 3.0 now has multisite capabilities built right into it, and Bjorn Wijers, a friend of mine and one of Holland’s top WordPress developers, has created a really cool plugin to handle content aggregation. Called bbAggregate, this plugin doesn’t just collect posts from blogs to be displayed on the home page, it allows you to display aggregated content on any of your network’s blogs. And to do this it introduces the concept of streams.
Streams
Once installed, bbAggregate will allow you to create and manage so-called “streams” of content. If there are multiple bloggers in your network who write about cats, you could set up a stream called “cats”. Post authors would ten be able to add posts they write to the “cats” stream. At the same time, they can choose to show the “cats” stream on their blog. If others blog about dogs, setting up a “dogs” and a “pets” stream makes sense. It may help to think of streams as a type of category, but there’s a little more to it than that.
Control
Unlike with (site-wide) categories, bbAggregate offers fine-grained control over what is shown in a stream. You can exclude blogs, limit the number of posts per blog and set up pagination. There’s no per-post control over what is in the stream (other than by editing that post, if you have the right privileges), but the plugin makes it very easy to exclude blogs that don’t play nice.
Room for improvement
This is a brand new plugin. Considering how complex the underlying code must be, the currently released version is very mature. However, there are a few things I think could be improved. The main one is that in order to display a stream, some theme editing is required. This is a well-documented and easy process, but I’d love to see a more seamless integration in future versions. I’m pretty sure this can be done, and it would greatly improve the project’s change of being widely adopted.
If you’re looking for a flexible way to cross-aggregate posts on your multisite WordPress install, I’d highly recommended checking out bbAggregate.