Mike Ash on private APIs

Mike Ash has been rocking with his weekly Friday Q&As. From the “latest about using private APIs”:http://www.mikeash.com/?page=pyblog/friday-qa-2009-01-02.html:

“Remember that the cost is not just to you, but to your users. If you’re really unlucky the break will be so bad that it’s not even obvious that it’s your fault, and they’ll figure it out only after much head-scratching. Once they do figure it out, they will hate you if your fix doesn’t come really fast.”

My new app (not officially announced yet — more later) currently uses Quick Look as a significant part of the user interface. Quick Look is a private API on 10.5, but my hope was that surely it would be made public by 10.6. If I coded correctly for both cases (I have a 10.6 seed running here I can test against), then I could safely release the product and be reasonably certain that nothing would be break.

I’m now rethinking that, both because it looks increasingly like Quick Look will remain a private API even in Snow Leopard, and because I’ve gotten feedback that it’s not a perfect fit for how I’m using it anyway. At the very least I will turn Quick Look into a secondary option, something that wouldn’t be missed if it went away, and roll my own preview UI to be the default.