Tom Jordahl's musings

Brian Kotek blogged the result of some experimentation he did with Data Services Remoting (aka RPC) calls from Flex to uncover some relevant information on the ordering of calls from the client to the server.

Read about it in his blog post.

Alex Glosband, one of our lead QA engineers on the LiveCycle Data Services team, has posted a very helpful and informative description on why certain Flex applications might get the error:

Detected duplicate HTTP-based FlexSessions, generally due to the remote host disabling session cookies. Session cookies must be enabled to manage the client connection correctly.

Check out the full discussion on his blog: http://www.alexglosband.com/?p=3

Adobe has published a Capacity Planning Guide white paper that gives guidance and test results on how LiveCycle Data Services scales up to to thousands of end users.

Stealing from the introduction:

This document presents the results of software benchmark tests performed by Adobe engineers in 2008. These tests show how LiveCycle Data Services 2.6 software can scale and perform under load using various messaging scenarios that represent real-world situations. The goal of this paper is to provide a starting point for those who need to plan a hardware and software infrastructure that can scale to meet peak demand.

Check it out here: Adobe LiveCycle Data Services 2.6 Capacity Planning Guide

The BlazeDS HTML Livedocs are now updated to match the updated PDF files I posted about a while ago. This brings the BlazeDS document up to date with the release of LCDS 2.6, including a much better organization of the chapters to explain the RPC and messaging concepts.

I think most folks use the HTML version, not the PDF (I know I do), so it was pretty confusing having two different versions of the doc around, with the most popular being the out of date version.

Thanks to the documentation team for responding to our complaints!

In a follow up to my recent post about the new Java AMF client available in BlazeDS, I was recently asked how to send a 'typical' flash remoting request to ColdFusion.

Here is how you do that in Java:

Object[] args = ...
String sourceName = "my.cfc.path.Component";
RemotingMessage message = new RemotingMessage();
message.setMessageId(flex.messaging.util.UUIDUtils.createUUID());
message.setOperation("myCfcFunctionName");
message.setBody(args);
message.setSource(sourceName);
message.setDestination("ColdFusion");
Object returnValue = amfConnection.call(null, message);

and accessing the body of the response like this.

Object body = ((AcknowledgeMessage) returnValue).getBody();

Not that the "args" variable is an array of the arguments you are passing to the CFC function. It can also be a Java List, or a simple object. See the BlazeDS source for RemotingMessage.java for details. This sends the same kind of message that the mx:RemoteObject tag does in MXML, so in ColdFusion terms you are using the "Flash Remoting Update". If you use the 'raw' AMFConnection API, you would be using the "classic" Flash Remoting. Both will work, but I recommend using the RemotingMessage style.

What does this do for you? Well if you are exclusively using Flex as a client, not much. But if you would like to write Java code to invoke a CFC, this alows you to do that very easily.

You may not have noticed, (what, you aren't subscribed to the BlazeDS commits forum?) but a few weeks ago Mete committed an enhancement that adds a Java AMF client API to the flex-messaging-core.jar file in BlazeDS.

You can find a specification posted here and its linked from the Developer Documentation page.

What does this do? Well, you can use this API to call (from Java) Flash Remoting end points in BlazeDS, LiveCycle Data Services, ColdFusion, PHP or whatever you have that supports AMF. Which of course is a published specification.

This feature is available in any nightly build after 3.1.0.2602 or in the trunk nightly build. Find those builds on the BlazeDS build download page.

The documentation team has posted an update of the BlazeDS documentation that includes all of the relevant content from the new LCDS 2.6 Developers Guide.

By the way, here is a gateway page to all of the LCDS 2.6 documentation, which has been reorganized to be much easier to read and use.

The HTML in Livedocs has not been updated yet, but a new PDF version is available.

See details on the Flex documentation blog here.

For those who were unable to attend my session at CFUnited this year, the CFUnited blog has posted the URLs of many of the sessions that got recorded via Adobe Connect. My session was recorded and is now online here. This talk has some new content about the difference between BlazeDS and LiveCycle Data Services.

The audio is very "hot" - when setting up the microphone the output from the in-room audio system was just super loud so I am distorted, but I think the session is still tolerably understandable. I am much better in person however. See you at MAX 2008. :-)

Christophe has posted another really neat demo application that shows BlazeDS collaboration with an application that uses Messaging to allow more than one person to fill out a form at the same time. Not exactly practical in the real world, but a good example if the power of BlazeDS.

Check out this great sample application posted by Christophe Coenraets, complete with instructions and source code, showing a really nice mashup of Yahoo Maps, Flex and BlazeDS.

Back in January, Damon Cooper posted a really great chart of all the channels types and the pros and cons of each written up by Seth Hodgson, a member of the LCDS and BlazeDS teams.

I wanted to post this to my blog for two reasons. 1. In case you missed it and 2. Because I wanted to have a link to it easily available on my blog for future reference.

I recently got confirmation that I will be attending CFUnited again this year. I believe I will be giving the "Adobe Speaker TBA" talk on ColdFusion 8 and LiveCycle Data Services. I will make sure to include a good discussion about BlazeDS and how that fits in to the picture.

I always enjoy attending CFUnited. It is being held at a new location this year. There probably isn't going to be a Dave & Busters handy to play games at, which is was always a highlight. But the crowd is always good and I really enjoy the sessions. Should be a good time, see you there!

Adobe is hosting a free "virtual conference" this week. It looks like a really good lineup of topics, including Adam Lehman (CF Evangelist) on Whats New in CF8 (Today at 1pm PDT), CF and RIA's and a CF & BlazeDS talk both on Wednesday. Christophe Coenraets (LCDS/BlazeDS Evangelist) is also doing an intro to BlazeDS session (Tuesday 9am PDT) and a LiveCycle Data Services intro on Thursday.

The lineup seems pretty good and you can pick and choose which sessions you want to attend. Check out more details at http://adobe.com/go/2008_developer_week

There was a question over on the BlazeDS forums about weather Flex 2 would work with BlazeDS. The answer is most definitely YES. You can use Flex 2.0.1 hotfix 2 or Flex 3 with BlazeDS 3. Jon Rose also blogged about this question back in January.

Jon was getting a message:

“Destination ’simple-topic’ requires FlexClient support which was introduced in version 2.5. Please recompile the client application with an updated client framework.”

The “2.5″ in the message that refers to LiveCycle Data Services 2.5, which was shipped requiring a hotfix (#2) for the Flex compiler/SDK.

The AMF3 protocol did not change. The remoting and proxy services interoperate without issue between Flex 2 and BlazeDS.

However, the messaging and data management service implementations on the server required several core changes in channel/endpoint handshaking and in how messages are queued and routed to subscribers that are not backwards compatible with clients compiled against the ORIGINAL Flex 2 client library. This is a low level incompatibility, so previous messaging and data management code doesn’t need to be altered or edited in any way. You just need to recompile your app against the hotfixed Flex 2 or Flex 3 SDK.

Thanks for Seth Hodgson for the details about what changed (it predates me moving over to Data Services).

I gave my "BlazeDS Revealed" presentation to the ColdFusion Online Meetup group last night to about 55 people via Acrobat Connect. Charie Arehart does a great job of organizing these online-only meetings that cover just a ton of ColdFusion and related topics and each presentation is recorded so you can watch topics that interest you after the fact.

As he reminded me more than once last night, he is always looking for speakers.

The recording of my BlazeDS session is available here.

I will be giving a presentation about BlazeDS to the ColdFusion Online Meetup this Thursday, February 28. I believe anyone can join the Acrobat Connect room (from anywhere in the world, how cool is that?) and the session will be recorded so you can watch me again and again. :-)

Check out the details here.

Here is the description:

Recently Adobe announced the release of BlazeDS which will make some key server technologies open source and free to use in any application. These technologies are critical to building great applications with Flex and AIR. Tom will talk about exactly what you get in BlazeDS and how it relates to LiveCycle Data Services and will detail some of the reasons why you might want to use these server technologies. He will also explain how ColdFusion developers can take advantage of BlazeDS in their applications.

Today Adobe shipped Flex 3 and Air 1.0 along with releasing the open source BlazeDS technology. These are some amazing and world changing things that just hit the streets.

I'll let others talk about how revolutionary AIR is and how great Flex 3 is going to be. The BlazeDS open source project is what I am excited about (and not only because I work on the BlazeDS/LiveCycle Data Services team).

In a nutshell, two of the three important technologies included in LCDS 2.5.1 have been released a) for free (as in beer) and b) as open source. This means that you can use Remoting (aka Flash Remoting) and Flex Messaging in your Flex applications, backed by Java or ColdFusion, without any licensing whatsoever. You can file bugs on the technology in the public JIRA bug tracking system. You can even check out the source and see what makes it work (or debug a problem when it doesn't).

Anyway, the team is very excited about BlazeDS and the whole company is pumped for AIR 1.0. Check them out!

http://opensource.adobe.com/wiki/display/blazeds/BlazeDS

As I posted before, I am speaking at Flex Camp Boston on December 7, 2007. This promises to be a really great event for experienced to advanced Flex developers. As of today it seems it is 75% sold, but in order to make this a really successful event, the organizers are looking to sell out. So of course they are running a contest. So if you are a Flex developer in Boston and haven't signed up, please feel free to put my name in the "If you were referred by someone, please enter their full name." box when you register. As a reminder, the fee is only $10!

What I need to do is figure out if speakers are eligible for the XBox 360 Halo edition that is being given away, along with a ton of other stuff like: two tickets to 360Flex in Atlanta, a ticket to CFUnited in Washington, D.C., copies of Flex Builder, Adobe backpacks, and Ipod Shuffle and books from O'Reilly. I keep asking Santa (my wife) for an XBox for Christmas, but all I get back from her is dirty looks. :-)