Sunday, July 08, 2007

Jazoon 2007: Some more notes on last day

I'm just back from some dubbin' in Publin, I mean pubbin' in Dublin, so little time to write a full post. However, I did find the notes I lost from day 4 in Jazoon:

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Last Day. Neil Gafter on closures.

First talk OSGi from Ergon Informatik.

The speaker is really happy with OSGi. It's great, it works really well, etc. Running osgi demo.

Bundles/plugins managed in a phone on a console app called J9 Console.

Goes on to talk about RCP. eSWT for embedded. Subset for SWT. Can run without RCP/osgi context if you don't need them.

JFace, gui toolkit. eJFace for embedded.

eWorkbench lets you bundle simul apps running. eUpdate is the update mechanism that is in eclipse. Pretty cool, the whole update manager is run on an embedded device.

Services can be shared between apps in the same VM.

Issues they have encountered in eRCP. Useful list.

Use JFace fonts and typesets to avoid memory leaks.

Some negative experiences.. Complex bundle dependencies. The services have states to manage, and this can be tricky to learn. Plus all the usual embedded ui issues.

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Web 3.0/semantic web Q&A session with Henry Story following the previous session that we unfortunately did not attend.. Very interesting.

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Java and SecondLife.

Seems like SL has potential in using resources as in uri resources...

Abit about the SL script language. The scripts are only evalutated when in the SL engine, client side.

Scripts can also call http requests that the SL server will shoot off to external servers. 1 KB limit on the response. An example is a SL phone booth that shoots off SMS requests to external servers.

The 1KB limit can be workaround by having the SL object being able to respond with packets. Note that client code cannot be changed once deployed many places.

Communication is used between the client and an external server but needs to be done through a remote channel. The external server then XML-RCPs to the external server.

The java library (a port of the C# library) for utilizing SL clients is somewhat dead, appearantly. But offers good control.

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Sort of split in half when it comes to deciding on the next talk. It's either a very interesting presentation on Jackrabbit or a talk from Netcetera on the complexity of software.

After talking with David about Jackrabbit for a little while I decided to jump in on the talk bout Build-up of artificial complexity. A talk straight to my heart.

Code grows ugly. We all know the problem, so what is the solution? Discipline and modularity are old solutions. Reduce number of (external) components is another one. I like addressing every req with an external component. His advice is be sceptical and choose the frameworks/components you *like*.

People don't like being constrained away from their personal favourite tech stacks. Limitation is dangerous, so don't restrain too much.

Will read more of this stuff. Read Greene's essay, but can't find the article on the net. Will just have to wait for the slides to come online (nudge nudge, Jazoon).