Flex 3 and Cross-Versioning – The Marshall Plan

The “Marshall Plan” is the nickname for the SDK feature to support cross-versioning. I have personally got a lot of queries on cross-versioning from Flex users in India and abroad.

Quoting opensource.adobe.com :

The need for Flex to support cross-versioning was seen way back in Flex 2. In Flex 2.0.1, a cross-versioning scheme was implemented, but never officially documented. It involved the Singleton class, a bootstrap loader, and modules that shared definitions in the bootstrap.

As 3.0 neared completion, testing Flex 3 applications loading Flex 2.0.1 modules was found to be completely broken. APIs in the classes that needed to be in the bootstrap loader had dependencies on classes that could not be in the bootstrap loader without causing compatibility problems. It became apparent then that the “shared definitions” strategy was extremely fragile. Not only did it require a detailed understanding of ApplicationDomains and class dependencies, it required that all developers understand the bootstrap mechanism and not make API changes that would violate the bootstraps dependency requirements.

“The Marshall Plan” looks to solve this by loading SWFs compiled with different versions into separate ApplicationDomains and have them interoperate through event passing.In fact the term Marshall was derived from the aspect of the feature that uses shared events and/or the SandboxBridge to marshal objects across ApplicationDomains.

There’s a very detailed wiki page on the Marshall Plan and its effect on various aspects of the product like Modules, Other Flex Classes and Security. You can take a look at the wiki page here…

The release of this feature is planned to be done in the Flex 3.2 milestone, in the Fall 2008 (check out the other milestones here).

AIR Application Security from the User’s Point of View

The AIR runtime can be looked upon as one that mashes up Web and Desktop Worlds. It allows Web developers to now write applications for the desktop using familiar technologies like Flash, Flex, HTML & JS. There has been a lot of debate lately on what security holes these would expose and how attackers can exploit them and how we as common folk can guard against it.

This warrants a look at the AIR Security model and the hooks that the platform provides to guard yourself (a user) against attackers…

But, before I go forward I cannot but stress one fact

As a user, consider AIR apps as Desktop applications (because that is what they are) and ensure as much care while installing them as you would when you insall “any other desktop application”. DO NOT consider them like websites because you are now giving the app direct access to your system (again… Just like “any other desktop application”). Further, quoting the AIR1.0 Security Whitepaper:

“In general, users should not install any desktop application (including an AIR application) that comes from a source that they do not trust, or that cannot be verified. The burden of proof on security for native applications is equally true for AIR applications as it is for other installable applications.”

An Adobe Evangelist’s Day out at a Silverlight Training

Like Shaggy said: “It wasn’t me!”

I am talking about Serge Jespers. Serge is an Adobe Platform Evangelist in Europe (Belgium to be exact) who had attended a 3 day Silverlight training.

He’s written a blog post that he calls Silverlight: The good, the bad and the ugly

Check it out…

Learning Resources.pdf

Lately, I have been getting a lot of mails from people who want to start with Flex, AIR, BlazeDS..etc (The Adobe RIA Platform in short) and are looking for learning resources.

I have compiled a document of resources that I found most useful. This is in no way an exhaustive list, feel free to leave suggestions here and I will add it to the list.

Learning Resources PDF

ADC on AMP – A great resource for Flex Developers

We all are aware of the release of Adobe Media Player (AMP) which is built on AIR (and incidently in Flex). A lot of the popular networks like PBS, CBS, MTV and others have signed up with feeds for AMP. AMP is fast becoming a easier and more efficient way of content delivery for them and a better experience for the users.

Anyway, Adobe is also adding quite a few shows for AMP. One such very useful resource is the ADC (Adobe Developer Connection) channel. There all the adobe heavy-weights talkingabout how to do things effectively in Flex, AIR, Flash …etc

The latest talk is by our very own Ely Greefield, talking about Flex 4 and the way ahead.

You can catch the same content on tv.adobe.com, but the advantage with AMP is that you can save it and then view it at your leisure rather than having to be connected to watch it.

Go get AMP & Enjoy ADC 🙂