Chef de Cambuse

...cooking, cruising and wine

Archive for December 2005

worldclock pimp-up with javascript

written by Frank, on Dec 20, 2005 11:15:00 PM.

This morning I’ve read a posting about a little html worldclock, putting the airport code and the local time for some cities on top of a picture with an equirectangular picture of the earth.

Wc01
 Equirectangular projection of a composite satellite image (NASA)

Some words in advance - the guy who made this explicitly says that it was only a quick fun thing, so my babbling isn’t meant in any way as any kind of offence against him!

When I looked at the picture I thought: “nice”, and remembered one of my sons asking me for something similar a few weeks ago, to pin places where we’ve been or where friends live – something like a mini-frappr. Reading the comment of the posting where somebody asked for the source I thought by myself “why doesn’t he look at the html code” and as I was curious I did.

Wohoh, that was very 80s - if we would have had html then already.
Hey, we are in the 21st century, we are living in Web 2.0 wonderland, a place where JavaScript is meant for other things than just for the – aehm – reloading xxxxxx (censored by the ajax-department) of a page.

So I had this little idea of a web-service providing city names, latitude and longitude, timezone offset, maybe even more, and a JavaScript client fetching that data on startup, with a way to define and persistently store the personalized places you want to see, perhaps in a cookie (4k limit?) or on a server, dragging them to where you think they are if you don’t know the exact coordinates, which by the way seems to be a funny excercise to convert them to the corresponding ones on the picture…

After waking up I at least started with the JavaScript client, still with predefined cities, but no relo – aehm – ing after all.
Any suggestion is of course appreciated, as this was a quick one and for fun too.

modifying a wrong commit message in a svn/trac combo

written by Frank, on Dec 17, 2005 2:13:00 PM.

With svn and trac, the use of TracLinks is a brilliant and simple solution to document relations e.g. between a changeset and a ticket.

But what if the stupid thoughtless and unobservant developer mixes up these few little numbers that represent a ticket?

With direct access to the system where the subversion repository and the trac instance reside there is an easy way to correct this misery:

svnadmin --bypass-hooks setlog /path/to/the/svn-repository \
         -r  

trac-admin /path/to/the/trac-instance resync

And another layer 8 issue solved.

The -bypass-hooks option is necessary if the "pre-revprop-change" hook is not in place, albeit this has to be used carefully as it may bypass such things as email notifications of the change, or backup systems that keep track of revision properties.

progress with the new html SimpleVisu

written by Frank, on Dec 14, 2005 10:43:00 PM.

Visu-alpha-20051214More than a year after I started with the simple html based visualisation of our home-automation system I finally found some time to reimplement it.

But now based on the uebercool, all singing and dancing Ajax technology.
The picture is probably boring as I havn’t really worked on the widgets yet, but I tried to resemble the visu I’ve done in 2004.
Most of the interesting things are under the hood:

  • nearly everything is Javascript generated, meaning on loading of the page only some Javascript is bootstrapped which then requests the visualisation objects and generates the html code
  • CSS based, layout and appearance can easily be customised
  • no page reloads, all communications with the server part are made with XMLHttpRequest
  • better separation of presentation and application layer, despite the initial html/javascript bootstrap only events (e.g. object xyz has changed its value to n) are exchanged between the visu app in the browser and the server part
  • and in the end the best: EIB events are processed in realtime, a press of a sensor button immediately changes the representation of its object(s) in the browser

Aqualand gone bonkers

written by Frank, on Dec 7, 2005 11:19:00 AM.

AL0000-04EThis morning, precisely @ 9:23:18, my good ol’ Citizen Promaster Analog Aqualand started to beep continuously and the watch hands stopped moving.
While I was already thinking about the easiest way to service the watch – which was done in April 04(!) – I came around some hints on the net that this behaviour isn’t necessarily an indication for a battery failure only but could be evoked by some internal error too.

The suggestions are to reset the watch – unscrew the crown and press all three buttons for two seconds – et voilà, seems we have a working watch, or at least a silent one , again.