Tuesday, November 24, 2009

A few last comments on the Hackathon

This is a random collection of notes about things I learned at the Hackathon or shortly after.

The Hackathon was a lot of fun. Pamela Fox, one of the developers of Wave, gave a couple of presentations (1, 2).

There are some article on debugging Wave extensions for Robots and Gadgets. More handy debug tips here.

If you're writing a Robot in Java, a huge amount of support is available in Google's Eclipse plugins. Be sure to have Java 1.6 installed. If you already have an earlier version, you can install 1.6 on top of it, and just switch the preference within Eclipse. I think it was Windows -> Preferences -> Java -> something...

There is also an Eclipse plugin for Python called PyDev. I don't have a lot of experience with it.

One guy at the Hackathon wrote a robot in Groovy, a dynamic language that runs on the JVM. From what I could tell, it was working fine.

At the present time, Robots must be deployed to Google App Engine. This restriction will probably be relaxed, especially as non-Google Wave servers come on line.

App Engine doesn't run PHP (I had wanted to add Mediawiki to my web app) but if you really want PHP you can try Quercus.

App Engine has a great logging facility, accessible via https://appengine.google.com. You can put logging statements in Python code (import logging) or Java code (import java.util.logging) and both will dump info statements into the GAE log.

Google likes extensions to adhere to some design principles. These are designed to maximize the broad appeal of your Wave extension and to make it run faster. Google figures that slow ugly extensions will drive users away from their ads.

There was talk at the Hackathon (and I wasn't paying close enough attention) about people setting up Wave servers. If I set up my own server, can I issue my own invitations to people so that I'm not depending on Google providing invitations? That would rock.

More useful links:
Something that would be very valuable for robot development would be a lightweight Wave server simulator running in Python, probably using the classes in the Python Wave API. You'd want a way to simulate an on-going Wave conversation, and the simulator would send events to the robot.

Monday, November 16, 2009

Tinkering with Google Wave Gadgets and Robots

Google is hosting a Hackathon on Saturday focusing on Wave. For Wave, you can create Gadgets or Robots. I wanted to be able to monitor and control my house's non-existent burglar alarm and X10 appliances from inside a Wave. A Gadget is the best thing for that, which you'll see (entitled "Home Controller") on the right side of this blog.

Assuming my machine at home is running the client code (which doesn't really control anything, it just fakes it), you can use the command "feed the cat" with password "abcd" to change the cat's state from hungry to full, or "wait a minute" to change the cat from full to hungry. Be patient, it can take up to fifteen seconds before your command produces a visible result. The Gadget and the client code are both polling a teeny web service on App Engine which passes information between them, and the polling rate is not hasty. The Gadget's source is hosted on Google Code. A not-too-detailed description is here.

Robots require working directly with the Wave API, which Gadgets don't. Here is a Robot that will help you look stuff up in the Linux kernel source code, using the LXR website. To use the Robot in a wave, first add it to your Gmail contacts. Use the name "Lxreffy" and the email address "wware-lxreffy@appspot.com". Now go into Wave and search for the contact "Lxreffy", and you'll be able to invite it into any Wave. Then type "LXR: foobar" in a blip, and hit "Done", and it will append a series of web links to the blip showing where "foobar" appears in the kernel. Example screenshot below.

Another Robot uses SymPy to enable symbolic algebra to be done within a Wave. The "SymPy { ... }" piece is typed by the human user, and the Robot responds by adding the response from SymPy.

Rosie คือโปรแกรมคอมพิวเตอร์สำหรับการแปลภาษามนุษย์เขียนโดย Google. ลักษณะที่ฉันชอบไม่ได้งานดีมาก. ฉันจะใส่ข้อความภาษาไทยนี้บนบล็อกของฉัน.