I just noticed a new section on mmalc’s very helpful “Cocoa Bindings Examples and Hints”:

Observing a Collection

I have personally found this very confusing when I’ve used bindings in my projects. The problem arises when you’ve got application model data stored in some “free” data structure like a dictionary or array. The model data can be manipulated quite handily with standard UI and array controllers, but what about cluing the rest of your application into the change? I find the problem of “bottom-up” observing with deeply nested data models to be one of the hardest problems with bindings, both conceptually and practically.

To me, mmalc’s explanation just confirms what I thought was true: bindings kind of sucks for nested “pure” models. There often must be some custom code associated with your model, or else you’ll have to jump through hoops to observe the changes in the data from some higher altitude.

I’m not sure what Apple should do to make it better, but I hope they do it. Or is my desire to store everything in dictionaries and arrays just a flaw in my thinking? Maybe I’m asking for too much.

Scotty invited Gus Mueller, Guy English, Wil Shipley, and myself on board for a little post-WWDC chat.

If anybody missed the Apple Store CocoaHeads event during WWDC, and wants to catch up on what went down, Steve Weller was kind enough to record the entire thing. The audio files are being hosted by Brian Christensen of Alien Orb Software.

I think the event turned out really well, especially the Q&A session where the audience obliged with many an excellent question.

MarsEdit users may be noticing some weird behavior with WordPress 2.2 and the “allow comments” and “accept trackbacks” options.

I discovered a bug in WordPress 2.2 which causes these settings to show up as disabled when they’re not explicitly set by the client. Lots of MarsEdit users have probably never thought about these settings, because their blog default setting was exactly what they wanted.

If you’re finding yourself frustrated that all of your new posts are coming up “Comments Disabled,” then you can work around the problem by explicitly setting the default values that MarsEdit should send with your new posts:

1. Open your weblog settings by double-clicking its icon in the weblogs drawer.
2. Select the “Defaults” pane, and choose your desired settings:

   

I’m confident that the WordPress team will fix this soon, but until they do I hope this workaround will get you back on track.

Update: Spent some time working on this issue with the WordPress folks today. Turns out there are a couple problems in both the way that the server interprets these values, and in the way that MarsEdit expects the server to behave. Both WordPress and myself are making some changes that will improve this for everybody in future releases.

In the mean time, the explicit workaround as described above is still the best choice.