"tip-of-the-day" Posts

Tip of the Day – Updating to Flash Builder 4.0.1

I recently posted about Building AIR 2 applications with Flash Builder 4.

There is now an update for Flash Builder 4 which downloads and installs the Adobe Flex 4.1 SDK. According to Renaun Erickson’s post, Flex 4.1 includes Flash Player 10.1 and AIR 2.0.

Now, if you’re like me and loathe the Adobe Updater… then you probably turned off the Adobe Updater notifications.

So here’s how to update Flash Builder to version 4.0.1 which includes the 4.1 SDK.

Go to Help > Search for Flash Builder Updates…

Help - Search for Flash Builder Updates...

This will launch the Adobe Application Manager and then proceed to update your software, including Flash Builder 4.

== UPDATE ==

If you don’t see a Flash Builder update available in Adobe Application Manager, you can download the standalone updater from Adobe.

Update Progress

Update Complete

Once the update is completed you can see Flash Builder is now at version 4.0.1.

Flash Builder 4.0.1 about screen

And you now have the option for Flex 4.1 as an installed Flex SDK. You can use Flex 4.1 to develop against Flash Player 10.1 and Adobe AIR 2.0.

4.1 is now avaliable

Tip of the Day – Building AIR 2 applications with Flash Builder 4

:: Update ::

This process has gotten much easier, you can now use software update to get AIR 2 as well as Flash Player 10.1 in Flash Builder… check out this post.

Adobe AIR 2 and Flash Player 10.1 were released on June 10th, 2010. It’s an exciting time. This weekend I decided to do some development on AIR 2 to try out some of the new features.

On the Adobe AIR Team blog’s post they mention that the free standalone download of the AIR 2 SDK will be available on Tuesday, June 15th… but I wanted to play with the SDK today.

So I went over to the Adobe AIR labs page and downloaded the AIR 2 Release Candidate SDK which is –> here.

You can download the released SDK from –> here

After downloading the Adobe AIR 2 SDK, I followed the directions on the release notes which explained how to overlay the AIR 2 SDK with my current version of Flex 4.

I’m on a mac, here are the commands I used in Terminal:

cd /Applications/Adobe\ Flash\ Builder\ 4/sdks/
cp -r 4.0.0 4.0.0AIR2
cp ~/Downloads/air2_rc1_sdk_mac_051110.tbz2 4.0.0AIR2
cd 4.0.0AIR2
tar jxvf air2_rc1_sdk_mac_051110.tbz2

I then added a new SDK to the installed SDK’s inside of Flash Builder:
Installed SDK's in Flash Builder 4

Now, I already had an Adobe AIR application project set up, and I switched over to the new SDK the I installed:
Switched over to Flex 4.0 (AIR 2)

However, when I tried to run my AIR application, I ran into this error:

VerifyError: Error #1014: Class IIMEClient could not be found.
	at flash.display::MovieClip/nextFrame()
	at mx.managers::SystemManager/deferredNextFrame()[E:\dev\4.0.0\frameworks\projects\framework\src\mx\managers\SystemManager.as:267]
	at mx.managers::SystemManager/preloader_preloaderDocFrameReadyHandler()[E:\dev\4.0.0\frameworks\projects\framework\src\mx\managers\SystemManager.as:2460]
	at flash.events::EventDispatcher/dispatchEventFunction()
	at flash.events::EventDispatcher/dispatchEvent()
	at mx.preloaders::Preloader/timerHandler()[E:\dev\4.0.0\frameworks\projects\framework\src\mx\preloaders\Preloader.as:488]
	at flash.utils::Timer/_timerDispatch()
	at flash.utils::Timer/tick()

After doing a bit of research I found out that my Adobe AIR project’s application descriptor file wasn’t using the correct namespace for the AIR 2.0 SDK. According to the Adobe AIR 2 Release Notes:

You must update your application descriptor file to the 2.0 namespace in order to access the new AIR 2 APIs and behavior. If your application does not require the new AIR 2 APIs and behavior, you are not required to update the namespace from 1.x based namespace. To update the namespace, change the xmlns attribute in your application descriptor to: http://ns.adobe.com/air/application/2.0

Sure enough, I hadn’t changed my namespace from AIR 1.5.3 to AIR 2.

I made the change in the descriptor file, and now everything works perfectly.

Developing games with PushButton Engine – Understanding Local Flash Player Security

As I spend more and more time on the PushButton Engine Forums, it’s funny how often the same topic seems to come up. Today a topic showed up again, regarding running Flash swf files locally. You see this same topic in many different flavors…

  • When I email my game to the client it won’t run on his computer
  • Playing the game only works inside my Flash Builder (or Flex Builder) project development folder
  • My game worked perfectly in one folder, but no longer works when moved to another folder

These issues are all part of the same underlying problem, a misunderstanding of Flash Player Security.

The first question you should ask yourself is… what security sandbox type is my game running in?

What is a Sandbox Type?

The sandbox type indicates the type of security zone in which the SWF file is operating.

Please remember that the security sandbox is determined at runtime, not compile time!

In the PushButton Engine we make identifying the security sandbox easy. When your game starts it logs the security sandbox that your swf is currently running (you can also get this by using the built in “version” console command). It looks like this:

PBE - PushButton Engine - r841 (ZaaBot build #97) - flash - localTrusted

In this case, the game is running in “localTrusted”. Most games that you run from Flash Builder will run in the localTrusted sandbox type. This is because Flash Builder configures your system to trust files in Flash Builder project directories. This is meant to make our lives easier as Flash developers… but it can cause confusion.

You can figure out what sandbox you’re running in by checking Security.sandboxType at runtime.

So what are the types of sandboxes?

In Flash Player, all SWF files are placed into one of four types of sandbox:

remote All files from non-local URLs are placed in a remote sandbox. Basically anything loaded from the web (ex: http, https) falls into this category. There is no access to the local filesystem.

local-with-filesystem This is the default sandbox for local files. SWF files in this sandbox may not contact the Internet (or any servers) in any way. They may not access network endpoints with addresses such as http URLs.

local-with-networking A SWF file in this sandbox may communicate over the network but may not read from local file systems. It is the exact opposite of local-with-filesystem.

local-trusted This sandbox is not restricted. Any local file can be placed in this sandbox if given authorization by the end user. This authorization can come in two forms: interactively through the Settings Manager or non-interactively through an executable installer (or created manually) that creates Flash Player configuration files on the user’s computer.

I added use-network=false to the compiler / flex-config file and it fixed it!

That’s great, but you still need to understand what is happening.

When you add the “use-network=false” parameter to your compilation, you are forcing the swf into the local-with-filesystem sandbox (“user-network=true” forces local-with-networking). This may end up giving you the desired behavior that you want, a swf that will run locally when you send it to your client or friends. However, you may run into some issues later on.

What if you and your friends were competitive, and you then decided your game needs to post a high score? You would need to make a request to a server to submit the score. When running in the local-with-filesystem sandbox you are not able to make requests of any kind to the internet, and therefore you can’t post to the score board.

So what is the solution?

You could teach all of your friends how to setup their game to run in localTrusted, by configuring their security files. But there has got to be a better way.

Well there is, and it all depends on how you plan to deploy your game.

I want to distribute a local game.

The recommended way to distribute flash games to be run locally is using the Adobe AIR runtime. It’s a great platform, and gives you much more flexibility and functionality.

I want to put it on a website.

So the best way to test your game then would be, to put it on a website. Now don’t get scared, this isn’t going to change your development workflow all that much.

The simplest way to simulate a local swf running on a website would be to have a local web-server running on you box. I highly recommend WAMP for Windows, MAMP for Mac OS X and LAMP for you Linux folk.

You then build your game (setup your output directory to drop the files in the web root) and launch your web-browser. Running a game swf from http://localhost will put your swf into the “remote” sandbox. You will want to do all of your testing within this sandbox, because it best mirrors the environment when you deploy your game to the web.

More Information

This post is just a brief overview of a very complex topic, for more information check out these resources:

Flash Player Security Basics

A full hour presentation from MAX 2008 by Deneb Meketa, explaining how Flash Player Security works and why it does it that way (if you don’t want to watch the whole thing, 47:12 is where it talks about local file security). I highly recommend everyone watch it:
Understanding the Flash Player Security Model

Tip of the Day – How to create a prompt field on your mx:ComboBox

For a long time I’ve been doing things like this within Flex.

[Bindable] private var _skills:Array = 
	{label: "---", id: -1},
	{label: "1 - Newbie", id: 1},
	{label: "2 - Some Experience", id: 2},
	{label: "3 - Expert", id: 3},
	{label: "4 - I'm a baller", id: 4}

And then binding this data provider to a ComboBox…

<mx:ComboBox id="skillsCB" dataProvider="{_skills}" />

Well it turns out there is a much easier way of doing this that I never knew of until today. ComboBox has a “prompt” attribute that you can set. It’s so easy…

<mx:ComboBox id="skillsCB" dataProvider="{_skills}" prompt="---" />

I told you it was easy. Can’t believe I never noticed it before.