At work we decided to give Flex2 a lengthy, honest trial run as a replacement of the Html/JS used for an important component of our application suite. It is an intranet sort of application where we controlled the environment and it seemed like a promising place to put Flex2 to work.
After months spent learning and becoming accustomed to Flex2 our team decided it simply is not a technology ready for building enterprise applications. We are now taking a pragmatic approach: continuing with Html/JS but using the Flex-Ajax bridge for charting, graphics, and multimedia. In my opinion these are things Flex2 is great for.
To anyone that may be considering the Flex2 platform, know that you will find large crowds of evangelists (many of them Adobe employees) on the web describing trivial applications and simple examples to make Flex2 sounds like a fantastic way to solve problems. When we starting dealing with hard problems our experience was extraordinarily negative.
My biggest issues with Flex2 are the following. My viewpoint here is largely a comparison of Flex2 against Html/JS for building rich internet applications. Though based on months of nontrivial development these are my individual opinions.
- It is not production ready. It is not a stable product. We have an internal wiki page titled “Flex bugs & gotchas” and its content has grown to a substantial size. Take a look at the latest hotfix notes to see what sort of nontrivial issues are just being addressed.
- The community is small and inexperienced. Flexcoders and Flexcomponents are great groups if you have trivial questions. We asked a half dozen hard questions over the last few months and those were met with either complete silence or confirmation from a Flex team member that we had bumped into another known bug with no confirmed fix date. Compare this to the mailing list and forums for Spring, Hibernate, JS/Dojo/Prototype/DWR, or PostgreSQL where your questions are answered so thoroughly that you feel questions far more difficult than the ones you face have already been conquered by people more knowledgeable. Patches to specific issues are also the norm in these communities. Maybe patching the Flex2 SDK is an easy process, I didn’t try it.
- The livedocs are down more than they are up. These would be pretty helpful if they were reliable.
- Existing examples of reasonably nontrivial Flex2 applications on the web are really buggy. Go visit the Flex2 search appliance or the golf store that someone made (can’t remember the url right now – will look it up) with a debug version of the flash player installed and watch the errors bubble out.
- The tools are not established. Flex-Ajax bridge is bugged. ExternalInterface is profoundly bugged (see my earlier post about this). The Flex Ant tasks are bugged (only with the most recent update did a failed compile cause a build to fail and most of the command line arguments aren’t stubbed into their corresponding ant tasks). Want to display some HTML in your application? Get ready to wrap your application in an HTML container, invoke an iframe in that container, and then hack massage it into place over your application so that it looks like it belongs there. Granted, all of these tools are still in Adobe labs so it is fair to expect alpha-ish quality, but I need real tools now to build applications with.
- Adobe’s priorities with this platform are exceedingly frustrating. They are working on Apollo and Flex3 while huge, show-stopping bugs exist in Flex2 and prevent it from being a viable alternative to more established technologies.
- Flex Data Services might be a good thing. It might even make the platform reasonable for an enterprise-grade application but it costs $20k per CPU. I can buy a beefed out database server with dual procs, 16gb RAM, and a 16 disk sata raid array for less than the price of licensing one of its CPUs.
- It is extremely difficult to find talent with Flex2 experience or a desire to obtain it. We want full-time, exceptionally intelligent software engineers. Our efforts to find Flex2 developers brought us contractors that refused to work onsite and people that think knowing individual, popular languages is more important that understanding the concepts that make them the same. We work with area recruiters and the vibe from them was much the same.
- The evangelists drive me nuts. They are too worried about presenting Flex2 as the slickest piece of engineering ever created to discuss the real issues that prevent real work from being done with it.
- While not unique to Flex2, the compile cycle is killer. I found over time, as our application grew, it completely crushed my productivity. Compare this to pressing F5 with the alternative.
- FlexBuilder is worth $10 and not $749 (that’s with charting, but if you are using Flex2 you should take advantage of the charting). No refactoring, no find usages, no code generation, plugin problems (we had a hard time getting subclipse and some other plugins to work with it), awfully unimpressive automatic importing, ctrl-space completion, ctrl-click, etc, etc. Comparing the Java intelligence of IntelliJ/Eclipse to FlexBuilder isn’t fair or applicable, but comparing the Html/JS intelligence of those tools to FlexBuilder is and they put FlexBuilder to shame. The design view, though helpful in some situations for coders, is not a design tool. Our designer hated it. The debugger pales in comparison to a Firefox instance with Firebug and the web developer toolbar installed.
- Flex2 without FDS does not play well with anything other than xml or web services. I can tell by the search terms used to find this blog that people are interested in using DWR with Flex2. We built an Html/JS container that provided a communication layer between Flex2 and our exposed DWR objects and though it worked for basic calls (did not handle timeouts, call batching, or reverse Ajax/Comet) it meant involving a 3rd debugger in development and it was really just very difficult to work with so many layers at the same time. Regardless I will try to post the code in the future to help anyone else in the same boat.
That said, Flex2 is great for making pretty things involving charting or multimedia. Our frustration began and grew as we tried to complete the nuts and bolts of a large enterprise application with it. If your application is heavy on the areas where Flex2 shines, then it may be worth the frustration. Perhaps your experience has been different? All I know is we are back to Html/JS using DWR for transport and Xulrunner/Firefox for the environment and getting work done again. Apollo sounds promising, but I am more excited about Xulrunner and Firefox3.
My advice is this: If your team has 1 or more of these following trends in place, I would strongly discourage a move to Flex2:
- You are building an application for the public (you do not control the environment or user base). Flash player 9 is not ubiquitous and the 96% flash player penetration number that the evangelists trumpet include all versions of Flash player. Flash player 9 is no where near 96%. Though it wouldn’t be fair to not mention that MySpace and Youtube are going to help Flash player 9′s penetration number increase faster than version 8′s.
- You have solid Html/Css/JS knowledge in place now. While I prefer this stack enourmously over Flex2 I also realize there is a learning curve involved. If you have already conquered that learning curve rest easy knowing you are using the superior tool.
- You are building business applications or applications that aren’t heavy multimedia. Flex2 is great for multimedia and I don’t hesitate to admit its superiority here. Keep in mind that you can use the ExternalInterface or the Flex-Ajax bridge to use Flex2 widgets inside your Html/JS with relative ease.
- You are building large applications. For smaller applications Flex2 is fine. Cairngorm helps (and in fact may help you keep your sanity) but it doesn’t solve all of the problems.
- You don’t currently have nightmares about scrollbars and don’t want to start having them This will only make sense to someone who has worked with Flex2.
Needless to say, probably the last Flex-related post for this new blog except for the DWR bit or unless I have something interesting to share related to the charts and multimedia strengths we will continue to use. I tried to keep this post objective; it does represent 6 man months of experience. I love many of Adobe’s products and I recognize that there are several cases where Flex2 would be a great tool. Large, enterprise applications is not one of those areas.
That said, it is a new tool in my toolkit and because it has obvious strengths I can certainly see myself using it for those strengths in the future.