So I, like a zillion other Apple fanbois, updated to Mavericks yesterday. Yay for free upgrades.
Overall, I’m impressed. It feels faster, I love the proper support for multiple monitors, iBooks on the desktop is a win, and the iCloud keychain works as advertised, with syncing to my phone.
But there’s one big negative – I’ve had multiple episodes of “applications randomly freezing”. When this occurs, the application _that I’m currently using_ just stops. It doesn’t crash, it just pauses. For a few seconds, or a few minutes, then it resumes. I can go use other apps, and they’ll work – or they might pause as well. It’s only been a day, but I’ve had 4 of these episodes so far – once last night shortly after upgrading, which I kind of shrugged off, and then 3 this afternoon, in about a 2 hour period. (Worked fine all morning though).
If I had to guess, I’d say it’s the new memory compression feature – but I had it occur just after a reboot this afternoon, with no other apps open. Then this evening it’s working fine again.
The other likely explanation is a clash with 3rd-party apps – I don’t run that many, but you never know.
In any case, I’m going to be doing a clean install to an external disk to see if it reproduces there – if it doesn’t happen there, then it will be a clean install for the laptop as well this weekend.
If you’ve had issues like that, feel free to leave a comment.
Update: Well, it just happened again. The only observation I can make is that it was while doing a build for the project I’m looking at – it’s quite possible that it was trying to compact memory or move stuff to swap. I wonder if the swap partition is corrupted?
Update the second: As it turns out, my hard disk had started reporting SMART errors the day before I download Mavericks. Bad timing. The freezes were being caused by I/O errors – sure enough, when reading from the swap file (not partition).
This is a rant about a bug report I raised with ExtJS a few weeks ago. That said, I’m using the bug more as a teachable moment than anything else; I’m certainly not trying to bag ExtJS (which I quite like, despite some of its quirks). But this bug does highlight a number of “things done wrong”, which I want to learn from so that I don’t commit the same errors.
(No knowledge of ExtJS is required, and whilst I will describe the details of the bug in depth, the technical issues involved aren’t meant to be the takeaway points)
One of the really nice features of ExtJS, to my mind anyway, is the rich model architecture, and how models can be associated with each other. However, the quality can be a bit erratic – certainly, it appears that the HasOne association (which allows a one-to-one relationship) could use some loving, as it isn’t as well developed as the more commonly-used HasMany
Wow, it’s been a while since I posted something…
ExtJs includes a sub-framework for turning JSON (or XML) data into ‘models’, including nested data. It does this by providing ‘reader‘ classes that understand JSON (or XML). However, it only understands nested arrays. Sometimes what you have is a nested object – e.g. when you serialize a HashMap from Java into JSON. Fortunately, it’s possible to extend ExtJS and provide a new Reader – one that understands nested objects (aka ‘maps’, or ‘hashes’, or ‘associative arrays’).
If you’re using ExtJS, I hope you find this useful.
It’s becoming quite common for employers to ask to see code samples from prospective developers. This doesn’t really go far enough.
The next step up is to see the VCS history as well. A small sample – say, a couple of hours of work – can reveal a lot about how a person works – more than the code itself. Do they write tests first, or do they backfill later? Do they refactor their code to promote readability? Do they commit regularly, with meaningful comments, or do they just push bits in randomly?
So the next time an employer asks for a code sample, take it up a notch and give them the entire history as well. (And yes, I practice what I preach)
Inspired by reading this article over at ZeroDistraction.com
While I don’t actually care about many of the features the author cares about (e.g. I prefer to do podcast discovery on my laptop), I do agree that the app feels clunky.
Update: Podcasts listened to using this app don’t get recognised as ‘played’ back in iTunes. Presumably that will get fixed with an iTunes update with iOS 6, but still… that’s the nail in the coffin for me. I won’t be using this app again until iOS6 is out proper.
Update the second: Heck, even after I manually updated the played status in iTunes, the Podcast app didn’t swap out the played episodes for unplayed. It did bring down new podcasts – but not new episodes.