Joe Developer thinks Twisted is overkill, so he tries to code his own server. But it can only serve one client at a time. But Twisted is overkill, right, so he tries some more clever ideas, with forkingTCPServer. Still doesn't work. So he finally tries out Twisted.

Twisted is:

• high Level: for basic things you need just a few lines. It makes the common case easy.
• with good abstractions. Try defer.Deferred() for processing values that don't exist, which is actually handy. That is a structured way for handling errors.

His Twisted program uses one thread at this point, which is not good when every line received takes long to process. To solve that you can use the process protocol. Or deferred.deferToThread()

You could use the standard python socket library. But Twisted was written because this is hard to use.

Okay, so I gave a talk myself on Europython. My brother wrote about it. You can get the slides at the Zest Software site. Click the red button next to the printer to get a Powerpoint-like presentation.

Holger Krekel thought the examples (adding for example Stories and Tasks to the live site) took too long. He would have preferred to see some more content like that already prepared. I tried that at the Zest office the week before and they told me to do more examples, so the truth is probably somewhere in the middle. :)

Someone else wondered if anyone at Zest Software could talk German. In that case he would probably want to hear this talk in I think the German Zope User Group (dzug). Also vielleicht gehe ich mal nach Deutschland!

I am at the Europython 2006 conference at the CERN in Geneva. I am holding a talk myself Monday. I will be writing about talks I visited here. Hm, I thought about making this an overview page with links to all the talks, but I think my main page on July 2006 should work fine actually. And as usual: see my brother's weblog

Works on CPS, a CMS for Zope. He is in charge of Ajax there.

What is Ajax?

A football club, a cleaner and a Web 2.0 technology: Asysnchronous Javascript And XML. Glue between application.

Examples: del.icio.us, flickr, digg, Google Mail.

Browser sends a Javascript call, server answers with just part of the page. This speeds up interactivity, saves bandwidth, avoids Flash.

Bad things to say about AJAX:

• Search enginges won't index your website right
• The back button is broken.
• Several others

These can be true, but you can work around it, except for the back button.

Choose a good toolkit. Lots of choices.

SSF: Server Side Javascript Generation Frameworks. Javascript dynamically created by the server.

• CrackAjax: change python to Javascript. But untestable and seems dead, but good idea, so keep an eye on it.
• Azax. Young project. Keep an eye on it.

Low level client side frameworks (CSF).:

• Test drive development doable.
• Ready to use
• Community. We choose the low level client side frameworks (CSF) as everyone seems to do that.

Ajax good practices

• Accessibility still matters. Keep it gracefully degrading your UIs. Blind people don't care about Ajax.
• It does bring pleasure.
• Practice Test Driven Development! Javascript deserves it too.
• Practice OO Programming, e.g. with help from Mojikit or other moders toolkits. Reuse.
• Continuous integration. Bundle your javascript tests in your python test suite. The scriptaculous test kit helps here.

CPS Ajax goodies

• nuxeo.javascript: provides all js libs in Zope 3 resources.

Conclusion

Ajax is not a revolution, but it is nice

More reading:

• Nuxeo blogs
• Planet Ajaxian
• Ajaxpatterns with lots of links

You can try it without frameworks, but frameworks help smooth away differences between browsers.

Download the full report (pdf).

This report is an overview of my practice at Zest Software. It was a fun and educating time, which is hopefully noticeable when reading this report.

The practice started on November 29th 2005 and ended at April 30th 2006.

Chapter 1 lays the foundation for this report. It introduces Zest Software and the main subject of the practice: the not yet finished eXtremeManagement tool. That is a tool for project management based on the Extreme Programming methodology. It is based on Python, Zope and Plone. A brief overview is given of these technologies.

Chapter 2 discusses several improvements that have been made to the eXtremeManagement tool. Three subjects are highlighted: workflows, task estimation and booking overviews.

eXtremeManagement was released on plone.org. The steps taken to do that can be interesting for others as well. That is why I generalised that process and put it in a tutorial on the documentation section of that website. Chapter 3 contains that tutorial.

Chapter 4 proposes some new features. Automatic assigning of new tasks has already been implemented. Better progress indicators and integration with a bug tracker are still on the wish list. eXtremeManagement should also be moved from the Zest code repository to the Plone collective.

The conclusion in chapter 5 is that the practice was successful. Moreover: I keep working at Zest Software for the rest of my study.