November 11, 2009
A Demonstration of the New Storage Volume APIs in AIR 2
Below is a screencast of an application I wrote called FileTile in order to validate the new storage volume APIs in AIR 2:
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Posted by cantrell at 6:52 AM. Link | Comments (0)
November 4, 2009
A Demonstration of the ServerSocket API in AIR 2
In order to validate the new ServerSocket APIs in AIR 2, I wrote an application called HTTPeek. HTTPeek is a proxy server that sits between your browser and the network, and can show you HTTP request and response headers. It can handle compressed content, chunked content, binary content, etc. Check out the video below to see it in action:
Continue reading "A Demonstration of the ServerSocket API in AIR 2"
Posted by cantrell at 8:20 AM. Link | Comments (7)
November 3, 2009
Some Interesting AIR Marketplace Statistics
A little over a year ago, I wrote a Python script to screen scrape the entire Adobe AIR Marketplace, download all the listed AIR applications, crack open the installers, and extract some statistics. My primary interest was how many HTML-based AIR applications were listed versus SWF-based applications, but I recorded some other interesting stats, as well.
I ran the script again the other day (after some updating since screen scraping scripts always break), and here's what I found:
Continue reading "Some Interesting AIR Marketplace Statistics"
Posted by cantrell at 7:54 AM. Link | Comments (5)
October 30, 2009
A Screencast Explaining and Demoing File Promises
File promises are kind of a difficult concept to describe, so I decided to explain them using a video. Hopefully this clarifies what file promises are, and why it's such a cool new feature of AIR 2.0:
Continue reading "A Screencast Explaining and Demoing File Promises"
Posted by cantrell at 6:11 AM. Link | Comments (2)
October 29, 2009
Exhaustive List of Everything That's New in AIR 2.0
This morning, I was going to start making videos demoing some of the new features in AIR 2.0 when I realized that I should probably start with a list of everything that's new. Below is an exhaustive list of everything that we're planning on including in AIR 2.0. I use the word planning because even at this relatively late stage, things can change. Consider yourself warned.
Feel free to post questions in the comments.
Continue reading "Exhaustive List of Everything That's New in AIR 2.0"
Posted by cantrell at 10:44 AM. Link | Comments (37)
October 28, 2009
Global Error Handling in AIR 2.0 and Flash 10.1
One of the most popular feature announcements during my MAX presentation was global error handling (GEH). GEH lets you handle all uncaught errors (both synchronous errors and asynchronous error events) in one place in your code. Here's an example of how it will work:
<?xml version="1.0" encoding="utf-8"?>
<mx:WindowedApplication xmlns:mx="http://www.adobe.com/2006/mxml" applicationComplete="onApplicationComplete();">
<mx:Script>
<![CDATA[
private function onApplicationComplete():void
{
loaderInfo.uncaughtErrorEvents.addEventListener(UncaughtErrorEvent.UNCAUGHT_ERROR, onUncaughtError);
}
private function onUncaughtError(e:UncaughtErrorEvent):void
{
// Do something with your error.
if (e.error is Error)
{
var error:Error = e.error as Error;
trace(error.errorID, error.name, error.message);
}
else
{
var errorEvent:ErrorEvent = e.error as ErrorEvent;
trace(errorEvent.errorID);
}
}
private function onCauseError(e:MouseEvent):void
{
var foo:String = null;
try
{
trace(foo.length);
}
catch (e:TypeError)
{
trace("This error is caught.");
}
// Since this error isn't caught, it will cause the global error handler to fire.
trace(foo.length);
}
]]>
</mx:Script>
<mx:Button label="Cause TypeError" click="onCauseError(event);"/>
</mx:WindowedApplication>
Registering for uncaught errors is hugely convenient, but it doesn't entirely excuse developers from handling errors where they're most likely to happen. For instance, you should still always register for things like IOError events and other errors that are likely to happen at some point, and that you can usually recover from. But starting with AIR 2.0 (and FP 10.1), you will also be able to register globally for errors that you weren't able to anticipate, and handle them at least somewhat gracefully.
The big question is what you do once you've caught an unhandled error. That will probably depend on the application. Since it's likely that a function exited without executing all the way through, there's no telling what state your app will be in. The safest thing to do is probably to log the error, show a very contrite dialog box, and then exit the app (after all, if the error had been predictable and easy to recover from, you should have caught it explicitly). You might try sending the error message to your server, including instructions for emailing the log file to a support email address, or if it's an internal application, provide a telephone extension to call for someone to come take a look. It's entirely up to you. We provide the API, you provide the solution.
Posted by cantrell at 10:46 AM. Link | Comments (7)
October 27, 2009
New AIR 2.0 API: URLRequest.idleTimeout
We recently added a new AIR 2.0 API which didn't make it into my MAX presentation:
URLRequest.idleTimeoutURLRequestDefaults.idleTimeout
These setters specify the amount of time (in milliseconds) that a connection will remain open before receiving any data. Certainly not as sexy as some of our other new features (native processes, file promises, multi-touch, accessibility, volume detection, socket servers, etc.), but if you're trying to use long polling, you'll probably find this API useful.
Posted by cantrell at 11:15 AM. Link | Comments (2)
October 26, 2009
Referencing ActionScript Reserved Words in E4X
If you have a chunk of XML with reserved ActionScript words in it, you won't be able to use E4X syntax like you're used to. For instance, say you need to parse the following XML:
var codeXML:XML =
<code>
<class name="Order">
<function name="getId">
<access>public</access>
<return>Number</return>
</function>
</class>
</code>;Since this XML is full of reserved words, you won't be able to access nodes like this:
trace(codeXML.class.function.return);
Instead, use bracket syntax like this:
trace(codeXML["class"].@name);
trace(codeXML["class"]["function"].access);
trace(codeXML["class"]["function"]["return"]);
Posted by cantrell at 1:19 PM. Link | Comments (5)
October 23, 2009
Generating Dynamic XML With E4X in ActionScript
E4X makes working with XML in ActionScript extremely simple. Creating some XML is as easy as this:
var inventory:XML =
<inventory>
<product id="111" price="2999.99">Laptop</product>
</inventory>;
But what if you want to generate the XML dynamically and use variables as attribute values or text nodes? Just use curly braces like this:
var products:Array = new Array();
products.push({name:"Laptop", id:111, price:2999.99});
products.push({name:"Mouse", id:222, price:49.99});
products.push({name:"Phone", id:333, price:199.99});
var inventory:XML = <inventory/>;
for each (var o:Object in products)
{
inventory.appendChild(<product id={o.id} price={o.price}>{o.name}</product>);
}The resulting XML is exactly what you'd expect:
<inventory>
<product id="111" price="2999.99">Laptop</product>
<product id="222" price="49.99">Mouse</product>
<product id="333" price="199.99">Phone</product>
</inventory>
Simple and elegant!
Posted by cantrell at 9:08 AM. Link | Comments (3)
October 9, 2009
My MAX Presentation is Online: What's Coming in AIR 2.0
A video of my MAX 2009 presentation entitled "What's Coming in AIR 2.0" is now online. You can also download the slides (PDF) separately.
Feel free to leave questions in the comments.
Posted by cantrell at 10:15 AM. Link | Comments (4)
