Saturday, January 28, 2006

Implementation of Standards (HTML & more)

As has been picked up all over the net Google has published some analysis of HTML used on the Web. Now some of the bloggers in the e-learning arena have picked up on this, notably Stephen Downs and Scott Wilson. I generally believe that people will only adhere to the standards when they are force to do so as normally it makes their life harder. As web browsers were lax in what they accepted most people were lax in what they produced, and it may be that web would be very different if web browsers strictly implemented the standard. So as long as the software implementing the elearning standards is strict in what it accepts and what it produces this should be ok. The problem is that at the moment this isn't the case. Our experienced in the Bodington community is that content packages produced by other elearning products need special code to deal with them as they are typically outside the specification. However at the moment the number of products is reasonably small so this is possible. And as Bodington is one of the smaller communities at the moment it is in our interest to interoperate as well as possible with the other products as people evaluating Bodington will blame Bodington if it fails to import a WebCT content package, rather than questioning if WebCT can product a correct one in the first place.

Saturday, January 21, 2006

Changing Unit on EKS Scales

We have some EKS Scales at home and they have no instructions and are stuck in imperial measurements. Here are my quick instructions for them.

Resetting Scales

Hold down the on button for 3 seconds and then release. After releasing - - - - should apear on the display (sometimes this doesn't) and the scales will reset to zero.

Changing the Units

Wait for the scales to turn off. Press and hold down the on button, 8 8 8 8 will apear on the display, continue to hold the on button until just the units are displayed (either lb oz or kg g) then release the on button and clicking the on button will move between the different units. Holding the on button down until 8 8 8 8 apears will save the setting. Hopefuly someone else will find this information useful.

Monday, January 16, 2006

Throwing nulls as Exceptions

Any ideas what will happen with this bit of Java and why?

        throw null;
    catch (Exception e)
        if (e == null)
                System.out.println("Exception is NULL");
                System.out.println("Exception is: "+e.toString());

Saturday, January 14, 2006

New WebLearn Build

The bug push is now over. The new build of WebLearn went live last Tuesday with a bug fix upgrade on Thursday to fix some minor errors. There are still a few minor bugs in the build which will probably get fix shortly and deployed in the next couple of weeks. Development now starts on the next set of WebLearn features. It looks like I'm going to be working on automatic login to WebLearn. Basically this means that to access public material on the site you won't have to login as a visitor, you will be taken straight to the material you requested. Currently if you link to a page inside WebLearn when a user follows that link they get asked to login before being allowed on to the page, one option is to login anonymously (if they aren't already logged in). This change will change WebLearn to work in a similar way to most other web applications where you can browse the site without logging in and only when you need to do you login. As a side effect of this change all public material in WebLearn will become indexable by search engines and so you will be able to find WebLearn through search engines such as Google and Yahoo. To try and help managers of material we are hoping to make it very clear which resources in WebLearn are publicly accessible but the method for doing this has yet to be decided.

Monday, January 09, 2006

Brutal Tomcat Shutdown

We have a copy of tomcat that is used here in Oxford for our automatic testing and it regularly runs out of memory due to the frequent reloads as the classloader memory not getting cleaned out. To prevent this from happen I attempted to restart tomcat every night in a cron job:

0 3 * * * ($HOME/tomcat/bin/ stop -force > /dev/null; sleep 10; $HOME/tomcat/bin/ start > /dev/null)

However it seemed that this was not working, the -force option was supposed to kill the tomcat process after attempting to shut it down gracefully. After reading through the script I discovered that I needed to set the CATALINA_PID variable for the -force to work. It would be nice if catalina would warn when you use the -force option without having a PID file.