My team is tasked with quickly evaluating SproutCore and a couple of other alternatives. There's not really enough time for a deep dive, but our findings might let us convince the powers that be to allow for a deeper dive. (Right now, we're just taking a quick glance to see "what's out there").
So me and a teammate have started looking at SproutCore. I'm loving it so far, but he has already decided he doesn't like it. The reason he doesn't like it is he got the impression that the "data binding" in the Todos tutorial is the naive kind of data binding that a Visual Studio grid control might do ... where the widget itself is allowed to reach across the Internet to the server and obtain new data whenever it needs to paint itself.
I would be shocked if that were the case, because it is such a naive approach that really is only good for demo-ware, and SproutCore feels much more elegant than that to me.
Unfortunately, we're probably not going to have time for either one of us to find out for sure. So, can someone who has used SproutCore and knows it well please explain a bit about how Bindings work, and whether or not Bindings are allowed to initiate an Ajax call to the server to obtain more data?
UPDATE: I got the answers I need, partly from the google group and partly from digging deeper. The Bindings are exactly what I thought they were ... a great tool for connecting objects in memory inside the Javascript environment. They eliminate a TON of "glue code", and, like the rest of SproutCore, are REALLY well done. In no way is it anything close to "naive data binding". SproutCore is one powerful, elegant library, and I hope to get plenty of chances to use it (though my current project, alas, chose to go with something else).
I don't think I qualify as "knowing [SproutCore] well," but I don't think your question is really about bindings per se; it's about what's allowed to poll the server for data. It's my impression that bindings largely talk to each other inside the application. A binding can change data in the (local) Store, but I don't think the Store necessarily initiates an Ajax call every time it's changed.
ETA: This work in progress reiterates, "Bindings are used for inter-object communication."