Category Archives: Tech Stuff

Grails BlazeDS 4 Integration Plugin

One of the main goals I’ve been pursuing for a few months is the integration of Grails with Flex 4. I need to rework ConferenceGuide‘s administration backend to make it more ergonomic so that we can cover more events, and ever since I discovered Flex 4 niceties, I couldn’t think of doing that with anything else. The problem is that none of the existing plugins suited my needs. All of them cover Flex 3 only, some of them introduce a lot of complexity for CRUD generation, some of them use GraniteDS instead of BlazeDS, and the simplest plugin, grails-flex has never gone further than the experimental stage. I did a lot of experiments, talked a lot about it on Grails mailing lists, until Tomas Lin kindly explained to me that maybe I was approaching it the wrong way. I wanted a plugin that would set up a complete environment for Flex developement right in the middle of my Grails application. And I wanted that because I wanted to avoid using Flash Builder (you know… Eclipse… ierk!), mainly because the only advantage of Flex Builder 3 over IntelliJ Idea was the visual designer. But he was right, I was wrong. Flash Builder 4 DOES change everything. It does include a lot of very interesting features that greatly improve Flex development productivity, especially when it comes to integration with backend technologies. And for those features, I can only admit that IntelliJ is not up to par yet. I’m still gonna use it for the Grails part, but Flash Builder will be my environment of choice for Flex 4.

So, once I learnt more about Flex 4, BlazeDS 4 and Flash Builder 4 beta 2, it was time to reconsider my approach and develop a much simpler Grails plugin so that any Grails application could be used in combination with Flash Builder. I just released grails-blazeds plugin to do just that. Here is how it works:

  1. Install grails-blazeds plugin: “grails install-plugin blazeds”. This plugin copies a couple of configuration files into your application and imports all of the required libraries, including BlazeDS 4 and Spring-BlazeDS integration 1.5, both in nightly snapshot versions, since they have not been officially released yet
  2. Create a service to be exposed to your Flex application over AMF, or choose an existing one
  3. Add @RemotingDestination annotation to your service class, and @RemotingInclude annotation to all of the methods in this service that you wish to expose
  4. Edit web-app/WEB-INF/flex-servlet.xml (created when you installed the plugin): uncomment the context:component-scan element and set the base-package corresponding to your service class
  5. Make sure your exposed service methods don’t use Groovy classes, either as argument or return types. This is a known limitation I’m still working on, but if there are some Groovy classes here, Flash Builder doesn’t manage to generate ActionScript counterparts.
  6. Run your Grails application using “grails run-war” instead of “grails run-app”. Once again this is a known limitation: Flash Builder BlazeDS data connection plugin relies on a classical web app layout and doesn’t understand Grails dynamic layout (that is until someone manages to create a Grails data connection wizard for Flash Builder 4)
  7. In Flash Builder 4 beta 2, create a new Flex project with a J2EE server. Here are what your parameters shoud look like, “conferenceguide” being the name of my Grails application and “sarbogast” being my home directory:

  8. Click “Data” menu, then “Connect to BlazeDS…”
  9. In the “Authentication required” dialog box that appears, check “no password required” box, and click OK
  10. You should see your service appear, and you can select it and click Finish.

  11. Your service should appear in the Data/Services view. You can then compose your user interface and drag and drop your service methods to the relevant components to connect them with your Grails backend.
  12. Don’t forget to configure a channelset on your service:
    <adminservice:AdminService id="adminService" fault="Alert.show(event.fault.faultString + '\n' + event.fault.faultDetail)" showBusyCursor="true">
    <adminservice:channelSet>
    <s:ChannelSet>
    <s:AMFChannel uri="http://localhost:8080/conferenceguide/messagebroker/amf"/>
    </s:ChannelSet>
    </adminservice:channelSet>
    </adminservice:AdminService>
    

And there you go. Special thanks to James Ward, whose screencasts really helped me get it right. Now the only thing that this plugin misses, beyond the 2 known limitations, is integration with Spring Security, but this is just a start.

Enjoy!

Fear, Uncertainty and Doubt

I have hesitated for a long time… a few hours that is. But given my geek reputation (of which I’m still proud by the way), I could just not avoid it: I have to say something about the iPad. Of course I was following the keynote live yesterday with a bunch of geeks in Café Numérique, in Brussels. And of course I was very excited about it. Now instead of writing long sentences about what I like and don’t like about it, I’ll just go over my impressions quickly:

  • I don’t really like the name, but iSlate would have been worst and Macbook Touch was clearly not adapted
  • I love the device itself, and yes I’m gonna get one as soon as it’s released. I’m planning a trip to WWDC in June and hopefully I can bring one back
  • it really is yet another game changer. Apple did with the iPad to the Tablet PC segment what they did with the iPhone to the smartphone segment: bypass the professional market, make it a general public appliance. Brilliant!
  • it will create a whole new market for new applications on the App Store, I can think of a few ones myself
  • I don’t care that it doesn’t have multi-tasking, I’ve never needed it and reactivity is too important for me
  • demonstrations in a couch, what a great communication symbol!
  • I don’t care about the batteries being sealed, so long as it gets me more battery-life
  • I hope there will be an Apple Care on this one
  • Absence of SMS and phone capabilities: it’s not a phone anyway
  • No front camera: who really uses video-conference in the general public anyway? Video-conference in a couch? Come on!
  • The price tag is just awesome. The top one is cheaper than my 3GS
  • I’m so glad I didn’t get a Kindle DX or a Nook as I intended to. By the way, even though e-ink is more comfortable to use, I think the generic aspect of the device and the availability of the iBooks store are going to marginalize specialize eBook readers
  • Stop it with the “giant iPhone” complaint. And laptops are mini-desktops, so what?

Now in parallel to all those impressions, I couldn’t help to see those floating images in my head, of websites with big blank areas and a blue logo, I could even hear those blank areas whisper in my ears: “No Flash support…. ouuuuuuuuhh… No Flash support”. Yes, I know, I’m going nuts. My first thought was “how are you going to explain your daughter that she cannot use the iPad to access her favourite color painting site with her fingers because there’s no Flash?” For such a general public family appliance, it just doesn’t make sense.

But then I started reading blog posts and comments about the announcement, and the frustration turned into anger. Anger against Apple and Adobe who can’t seem to find a common ground on this issue. But more importantly angry against all those self-proclaimed death prophets, all those open standard ayatollahs claiming that they don’t care about Flash since Flash is dead anyway, and Flash is closed and proprietary, and Adobe is all evil, and HTML5 is going to rule the world. And it kind of woke up the Flex developer beast in me, I turned all green, I tore my shirt apart, going all…

FUCK HTML5 !!!

And then I started punching around.

First off, Flash has evolved a lot in the past few years: Flash is not just used for ads anymore. It powers the vast majority of videos on the web, plus a lot of multimedia websites that we love and use everyday (Deezer for example, Google Finance, etc.)

Second, Flash is not completely open, but it is far less closed than what a lot of people know: Tamarin, the Flash virtual machine, the basis of the Flash plugin, has been donated as Open Source to the Mozilla foundation 3 years ago, SWF (Flash file format), AMF (Flash remoting protocol), RTMP (Flash realtime communication protocol) are all open specifications that allow anyone to write their own Flash plugin (with a licence, but still) or generator. Plus Adobe has gone a long way in opening up its tools and processes for the Flash platform as a whole by open sourcing the Flex SDK, creating the Open Screen Project, and I could go on and on. I’ve met some of the openness evangelists inside Adobe and I can tell you that they’re doing a great job opening up what used to be a very protective and old-school company. And it’s just the beginning.

Third: being an open standard is not a f***ing feature for Steve’s sake! If using committee standards means I have to wait for 10 years before any evolution becomes available (how long has W3C been working on HTML5? how long before it is finalized), if it means going back in time on problems we thought had been solved for good (like the video codec hell coming back from the dead), if it means having to spend hours tweaking my web applications so that they look and behave the same in all browsers, then I don’t give a sh*t about open standards. Where is the added value?

Fourth, I can already hear you yell at me about the last argument: “we just can’t let one (evil) company have so much control about a web technology!”. And still that’s exactly what Sun has been doing with another omnipresent web technology: Java. And very few people ever complained about it. And what about Google with Android? The truth is that, from a developer standpoint, having one company orchestrating the evolution of such a huge technology is very good: it guarantees a certain level of consistency, so that we don’t have to deal with compatibility issues between different implementations. It’s also a good point for stability, knowing that you will always have backwards compatibility and professional support on the long term, and that you can invest safely in the technology. And of course it’s excellent for efficiency, because they don’t have to waste time on endless arguments about who’s got the bigger video codec or whatever, so it evolves fast.

So that’s it. I hate HTML, Javascript and CSS, I do it when I have to, but it’s not development, it’s tinkering. And I hate all those people spreading FUD about Flash without knowing what they’re talking about. And I love the Flash platform, and what Adobe is doing with it. I just hope Adobe and Apple will eventually reach an agreement to bring Flash to the iPhone and iPad. And I hope Adobe will do some PR to fix their image because there’s a big problem there.

Just my 2 cents…

Here Comes Grails APNs Plugin

That’s it. I’ve released my first Grails plugin ever. Woooo! Champagne!

If you follow my Twitter feed, you’ve probably noticed that I’ve been playing a lot with Apple Push Notification service lately (APNs for friends). Indeed, ConferenceGuide still requires a data connection, which can be problematic on a lot of events because they’re usually abroad (and roaming fees are waaaaaay too expensive), and even when you do have a data connection, it’s usually pretty slow… at best. That’s probably why one of the most requested features for ConferenceGuide is Offline Mode.

But getting all the data directly from the server does have at least one advantage: you’re always up-to-date. And experience has shown that sh** happens: sometimes sessions are cancelled at the last minute, or a global sound mixer reboots out of nowhere, thus shifting all sessions by 15 minutes. Those of you who were at Devoxx last November know what I’m talking about. So I needed a way to combine the best of both worlds: being able to browse schedule and speaker information without a data connection, and still get updates whenever something changes and I can find a wifi hotspot or something.

The first part of the solution is the local database. The second part involves sending push notifications. The problem with the latter is that the API provided by Apple is pretty low-level and the documentation is rather scarce. And it’s understandable because they expose a service that should be usable by any server technology, whether it is Java, .Net, PHP, Rails, etc. Fortunately, Java has a huge community and a great Open Source spirit, so it wasn’t long before a few projects were created to build an abstraction layer on top of APNs API. The simplest and most documented one I found is java-apns by Mahmood Ali. But ConferenceGuide server is not plain Java. It’s Grails 1.1 (I haven’t taken the risk to migrate to 1.2 yet). So I wanted to ease the integration of java-apns into any Grails application. And voilà! Grails APNs Plugin.

Special thanks to Burt Beckwith for helping me get started, and Mahmood Ali for developing java-apns!