Category Archives: Flex

Adobe Provides Hosted Real-Time Data Services

Adobe announced the Cocomo beta at MAx last week. This is a service hosted by acrobat.com that allows developers to add real-time social capabilities to their applications. Cocomo also has Flex components that should make building these social applications really easy. You can sign up for the beta on labs.

Once I get some free time I plan on playing around with these new services and components. It looks very exciting. :)

MN.swf Camp 2009 Call for Speakers

Yes, we’re going to do it again! MN.swf Camp was such a huge success in 2008 that we’ve decided to make it an annual event. It will be held at the Library again this year on Monday, April 6, 2009.

We’re currently looking for people interested in speaking. If this is you, please go to the MN.swf Camp web site and fill out our speaker form. You don’t need to submit your session topics yet. We’ll be holding an orientation meeting for all interested speakers. After that meeting you will have a couple weeks to submit your final topic ideas and selections will be made.

AIR Distribution Kit

Tomorrow at FlashBelt I’ll be giving a presentation on Installation and Distribution Strategies in AIR. Since AIR applications are built using web technologies like JavaScript and ActionScript, many of the AIR users aren’t used to thinking about the installation and distribution strategies that desktop applications require. My presentation will cover a couple of these issues and show some sample solutions to these problems.

I’ll also be announcing the AIR Distribution Kit open-source project. This is a ActionScript 3 library for creating update functionality within AIR applications and for creating custom browser-based install applications (otherwise known as install badges). You can see more information about this project on my labs page. I just started this project, so there might be some bugs. Check it out and let me know what you think. Please let me know if you see anything you wish working differently or what features you’d like to see added in the future. If you’re interested in assisting with the development, please contact me.

Speaking at FlashBelt again this year

FlashBeltI’ll be speaking at FlashBelt again for the fourth straight year in June. I’ve spoken at this conference every year since I moved to Minneapolis in 2005. It’s a great conference that brings in both local and national attendees. My session is titled Distribution and Installation Strategies for AIR and will cover the following:

Flash and Flex developers have been spoiled by the fact that most of our applications are distributed over the internet through the browser and Flash Player. We didn’t have to worry about installation or updates within an application. This session will walk you through the process of building a custom badge using Flex that handles the installation, update and launch of your AIR application from within a browser. We’ll also look at how to implement an update feature within your Flex AIR application so your users can always have the most recent version of your application.

Firebug Target for Flex Logging Framework

We were talking about debugging Flash/Flex applications inside the browser the other day at MN.swf Camp and I mentioned that someone had created something called FlashBug that interfaced with Firebug. I’d never really looked into it much, but I knew it existed at one point. Well, it turns out the link to that is broken. So I did a little digging and found that the interaction with Firebug is super simple. So I decided to create a custom Target that works with the Logging framework in Flex. The following is an example of how to use this target:

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import com.dannypatterson.logging.FirebugTarget;
import mx.logging.ILogger;
import mx.logging.Log;
 
var logger:ILogger = Log.getLogger("myLogger");
var logTarget:FirebugTarget = new FirebugTarget();
logTarget.addLogger(logger);
logger.info("info from flex");
logger.error("error from flex");
logger.warn("warn from flex");
logger.debug("debug from flex");

Download the FirebugTarget class here.

Compiling XML Data into your SWF

Have you ever wanted to actually compile XML data into your SWF before? I wanted to do this to embed the build version into my Flex appliction. The version was stored in an XML file and updated during the build process. But I wanted the version to actually exist inside the SWF in order to decouple the depandancy on the external XML file at runtime. This way I don’t need to worry about the XML file not loading or getting seperated from the SWF. The version will always be there. Here is a simple example doing this in Flex.

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MN.swf Camp Sold Out

MN.swf Camp sold out in less than three days. We had to limit the attendees to 100 because of space limitations, however, we are currently exploring other venue options. If we can secure a larger venue then we will reopen registration. I suggest you sign up for the mailing list on the conference home page so you can be alerted if registration opens again.

MN.swf Camp is a one day conference in Minneapolis focusing on the Flash Platform for programmers. Its being organized by the MN.swf User Group and FlashBelt.

XOR Cipher Encryption in ActionScript 3

I typically use an external XML file in all my applications to store configuration variables outside my compiled SWF file. This allows me to make changes to those variables without needing to recompile the SWF application. This is really helpful if you’re deploying an application to multiple environments (development, staging, production). You can deploy the same application and just have a different XML file in each environment with different values.

The values in the XML file are easily read by anyone using a proxy like Charles or Service Capture. Therefore, I decided to put a simple encryption on the values I didn’t want people to be able to easily read. XOR Cipher encryption is a simple form of two-way encryption using a known key. This key would be compiled into your SWF application. So the only way someone could decrypt your variables would be if they decompiled your SWF or guessed the key. Obviously this solution is not hack proof, but it provides a road block for anyone trying to get at these values.

The following is an ActionScript 3 class that performs this XOR encryption. This encodes/decodes the XOR encrypted value using the Base64Encoder in Flex, so if you want to use this without Flex you’ll need to remove that dependancy. The xor() method performs the XOR encryption against the key. If you run a string through this method it with return and encrypted string, and if you run that encrypted string through this method it will return your original string.

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GZIP-Encoded HTTP Response in Adobe AIR

A common way to reduce the size of data returned over HTTP is to allow the web server to use a GZIP compression on the data. When making requests in a Flash/Flex application hosted in a web browser, the browser actually uncompresses the GZIP-encoded data before its delivered to Flash Player. Therefore, Flash/Flex developers don’t need to worry about GZIP-encoded data since its handled seemlessly behind the scenes. However, when writing an application in AIR, there is no browser to handle the GZIP compression and AIR 1.0 doesn’t have this built-in. (I assume they will add this in a dot release at some point.)

But there is a way to do it manually. The ByteArray in AS3 supports DEFLATE compression. However, you must first remove the header in the GZIP data for this to work properly. In my case, I was making a web service call using the WebService class in Flex. Since I actually needed to get at the raw binary GZIP data returned by the server, I had to change my code to use the low-level URLLoader class that is built-in to Flash Player.

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Making Flex Web Service calls in ActionScript

I was using Flex the other day to consume some SOAP web services. However, I needed a way to modify the SOAP header in the request. This is exposed by calling the addHeader method on the service. That was easy enough, but I was finding my code difficult to manage when the service was defined using MXML and I had to add the header in ActionScript. I never really liked using MXML to define non-ui elements, so I decided to just use ActionScript to define the entire service. I found that it wasn’t as straight forward as I thought it would be so I thought I’d post my code here for the benefit of the community.

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