Supersized Apps with AIR on iOS

One of our latest customer projects was mainly intended as an offline iPad app but should also ship on USB-sticks and run in browsers for all desktops. A perfect fit for Adobe AIR. Read here what we’ve learned.

Adobe AIR is really a powerful tool when it comes to projects for multiple target devices. We’ve already done a couple of projects based on our data driven ActionScript framework which runs nicely in any browser supporting the latest versions of Flash player, as standalone player for DVDs and USB-sticks and within the desktop version of AIR.

We spent a lot of time improving the iPad version to ensure good render performance and a really low memory footprint.

The project I’m talking about uses loads of assets, currently almost 2 GB of bitmap and video files (will grow) and 6000+ unique “slide” XML files with the actual content. Everything loads fast and smoothly with the browser and even faster on desktops and of course iOS.

Development

Development was pretty straight forward since we did most of the debugging with the local AIR application which is fast and easy to profile. After big milestones we also packaged the iPad version and tested directly on the device. This post is not about how you do this step effectively but keep in mind that thousands of files means long packaging time with ADT and takes XCode a long time pushing the app onto the iPad. Upgrading to a new SSD dropped packaging time significantly so using a really fast drive definitely pays of!

2 GB maximum size

With our apple development certificate it was no problem to install the app on all iPads, but it simply wasn’t possible with the customers release certificates. We figured out that there’s a size restriction for iPad apps which allows only 2 GB but we already had 2.2 GB. Boom. Luckily we where able to encode all the videos again and save almost 500 MB so we could ship for now.

Delivery

The customer uses an enterprise solution for delivering iPad apps to all it’s employees and it turned out that the technical provider restricts the maximum app size to less then 200 MB. Boom again.

AIR on iOS FileStream bug

So we implemented a rock solid update process which initially loads almost 1.5 GB of files but never completed on the iPad. The app crashed hard but was still open, crashed again hard after restart but completed the download process after another restart. We had a hard time tracking this issue down to it’s real roots and finally catched this error: 3005 - Insufficient system resources. Google found this Adobe forum thread about it which contained at least a workaround found by Jason Moore:

We did find a workaround , but using open() instead of openAsync().. everything then seems to function correctly.

Please vote for this AIR on iOS bug, it’s from 2011 but still open:
https://bugbase.adobe.com/index.cfm?event=bug&id=3077653

So if you struggle deciding whether AIR is a good fit for your big app I definitely say yes, but hopefully this post helps a little to ask the right questions and avoids running into the same issues.

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