I’ve spent a bit of time playing with moving my Typo filter patch to use controller instances for filtering, and it doesn’t look too hideous on the filter side, but I’m going to need a lot of infrastructure changes before I can deploy it.

Unfortunately, the main user of filters right now is Article#set_defaults, which is called whenever an Article is saved. If I make filtering a controller issue, then I’ll have to rip out the filtering in Article (also Comment and Page) and move it to ArticleController. This won’t be a big performance hit, because I can use fragment caching, but it’s very invasive.

So, before I go any further down this road, I need to decide if this is really cleaner then just caching a base URL and using it to manually generate URLs. I was originally against this, but a thread on the Typo mailing list reminded me that we’re going to need a base URL if we want to support multiple blogs in a single Typo install anyway.