Greg Wilson’s Ramblings

Most modern desktop applications, browser plugins, OS’s, etc. automatically check for updates periodically, and some of them even handle the update process with a single click so it’s easy to stay current.  When building AIR applications, it’s also important to provide a good auto-update feature.

During the past several weeks, I’ve been managing a project to build an internal AIR application.  I wrote the original requirements document but forgot to include a simple bullet about auto-updating.  A few days ago, I was handed the source code and other assets and quickly realized my oversight.

Thankfully, adding this capability is dramatically simplified by the Adobe AIR Update Framework that appeared on Adobe labs a few months ago.  There have been several blog articles about the new framework but I thought I would provide a very simple example of the most common update model.

The code below checks to see if a new update is available every time the program is run.  If an update is available, it simply prompts the user to install the new update with the following default UI:

I implemented this using the following 3 steps:

• I downloaded the AIR update framework from http://labs.adobe.com/wiki/index.php/Adobe_AIR_Update_Framework and copied the included applicationupdater_ui.swc to my project’s lib folder
• I created a file called update.xml (see tab 3 below) and uploaded it to the server where my .air file lives.  This file identifies the currently available version, the location of the .air file and provides the description shown above as “release notes”.
• I added code to my existing init() method to initialize the updater.  Once initialized, I triggered an immediate update check via a one-liner event handler.

Every time my application runs, it performs a quick check to see if the version number in the update.xml on my server is different than the version number in my app config file (UpdateSample-app.xml).  If it’s the same, the user sees nothing.  If it is different, the dialog above displays.  The update framework takes care of the dialog, downloading the new air installer and the installation of the new version.  If there is no connection to the server, it silently continues running the existing version of the application.

There are many other options included in the framework, including the ability to have the update check occur every n days.  For more details, see the included documentation and the included samples.

Try out the results

To demonstrate this capability for this blog post, I created a tiny AIR program.  Download UpdateSample.air 1.0 and install it.  It simply displays a small window with the current version number displayed.  When you run it, it will immediately tell you that v1.1 is available and prompt you to install it so you can see the end-user experience.

UPDATE 11/26/2008 - http://gregsramblings.com/2008/11/26/adobe-air-update-framework-for-html-ajax-and-flash-applications/

Source Code

Below is the source code to UpdateSample.air and the update.xml that resides on the server:

P.S. I will be doing a short article about the code viewer SWF used above that I wrote in Flex.  I’ll also explain how I got it to work on the WordPress hosted service, wordpress.com, which doesn’t allow flash in blog post (at least not directly).