The Windows Runtime API Windows.Foundation.Collections.PropertySet class is a nice string name to object value map that has a changed event that fires when the contents of the map is modified. Be careful with this event because it fires synchronously from the thread on which the PropertySet was modified. If modified from the UI thread, the UI thread will then wait as it synchronously dispatches the changed event to all listeners which could lead to performance issues or especially from the UI thread deadlock. For instance, deadlock if you have two threads both trying to tell each other about changed events for different PropertySets.
My second completed app for the Windows Store was Words with Hints a companion to Words with Friends or other Scrabble like games that gives you *ahem* hints. You provide your tiles and optionally letters placed in a line on the board and Words with Hints gives you word options.
I wrote this the first time by building a regular expression to check against my dictionary of words which made for a slow app on the Surface. In subsequent release of the app I now spawn four web workers (one for each of the Surface's cores) each with its own fourth of my dictionary. Each fourth of the dictionary is a trie which makes it easy for me to discard whole chunks of possible combinations of Scrabble letters as I walk the tree of possibilities.
The dictionaries are large and takes a noticeable amount of time to load on the Surface. The best performing mechanism I found to load them is as JavaScript source files that simply define their portion of the dictionary on the global object and synchronously (only on the worker so not blocking the UI thread). Putting them into .js files means they take advantage of bytecode caching making them load faster. However because the data is mostly strings and not code there is a dramatic size increase when the app is installed. The total size of the four dictionary .js files is about 44Mb. The bytecode cache for the dictionary files is about double that 88Mb meaning the dictionary plus the bytecode cache is 132Mb.
To handle the bother of postMessage communication and web workers this was the first app in which I used my promise MessagePort project which I'll discuss more in the future.
This is the first app in which I used the Microsoft Ad SDK. It was difficult to find the install for the SDK and difficult to use their website, but once setup, the Ad SDK was easy to import into VS and easy to use in my app.
Perfect Stranges video game (via The World Deserves A Perfect Strangers Video Game. Now, It Has One. [Perfect Strangers])
Documentation for the VS JS profiler for Win8 HTML Metro Apps on profiling apps running on remote machines.
Anecdote on software usability. FTA: “… and suddenly realized that it was a perfectly ordinary whiteboard felt-tip pen. The headwaiter just draw an ”X” over their booking, directly on the computer screen!”
(via “What’s the waiter doing with the computer screen?” (javlaskitsystem.se))
In short: excessive use of promises leads to a ton of short lived objects and resulting poorer pref.
The setImmediate DOM method is like window.setTimeout(callback, 0) but better.
There’s weird stuff you’d think is public domain but isn’t including Martin Luther King Jr.‘s “I Have a Dream” speech. FTA: ”If you want to watch the whole thing, legally, you’ll need to get the $20 DVD.
That’s because the King estate, and, as of 2009, the British music publishing conglomerate EMI Publishing, owns the copyright of the speech and its recorded performance.”
Fascinating anecdotes on criminal investigations involving game consoles.
Cool and (relatively) new methods on the JavaScript Array object are here in the most recent versions of your favorite browser! More about them on ECMAScript5, MSDN, the IE blog, or Mozilla's documentation. Here's the list that's got me excited: