paulbooth.com

I’m currently using my train commuting time to read Turtle Geometry and experiment with turtle graphics in AS3. I’ve got a basic turtle graphics class up and running and plan to move on to writing a simple LOGO interpreter to control the turtle along with a flex based IDE to create and archive the logo programs. The only problem I’ve got is to make sure I get on with the coding instead of playing with the turtle, it’s very addictive to keep tinkering with the parameters on a simple set of turtle graphics commands and to be amazed by the outputs. This morning I was playing with a simple turtle geometry circle (go forward 1 unit then turn right 1 degree and repeat 360 times). This is what happens if you create many circles (in random shades of red) with a small turn of the turtle between each new one -

I thought the centre of this image was interesting so I adjusted the parameters to draw very big circles and got the following hypnotic images -

I’ve spent the last three days at Flash on the Beach in Brighton. I had a great time even though I’ve been feeling unwell thoughout (have some kind of cold which is making me feel exhausted most of the time). I saw some inspiring sessions - Hoss and Graig Swann stood out for me. I was also excited by the Flex and Apollo talks - Mark Anders session in particular was very useful to me and I’m going to get to work on some flex components during my train commute time.

I’m planning to increase my Flex skills alongside my current day job as a C# web application developer. I’m looking forward to the day when enough business users have seen great Flex apps out there in the wild and realise that they want one of those rather than a second-rate application interface based on dated HTML form controls (even with new improved Ajax).

Tagged with: fotb06

I’ve been using SSIS on my current project to read and transform data from a legacy database into a shiny new one. One of the first things I wanted to do was to log errors in a way that allowed me to easily review (and sort) the log output.

Picking up errors from a lookup was easy enough, I just used the red error output (after clicking on ‘configure error output’ to set lookup failures to redirect rather than fail) to direct the error flow to a script component. Initially, I was using the script component to write to a text file using a command such as

Me.Log("Contact '" + Row.ContactName + "' does not exist", 0, Nothing)

but the resulting text file end up containing far too much extra system text that it was too much trouble to extract the information I wanted. As a result I chose to write my log information to a database instead. I used a MigrationErrors table with three varchar columns - error code, error description and extra data. This allow me to easily sort and review the errors.

I used a Derived Column Transformation to populate the error code, description and extra data. The extra data tended to be a comma delimited list of useful field values to help me track down the problem. One thing to note is that in order to write numeric values you need to cast the value using something like

stringValue + "," + (DT_STR,10,1252)numericValue + "," + otherStringValue

The next problem, however, was how to write to this log when I was processing data in the script component which doesn’t have an error output like the lookup component has. Luckily, after a number of searches with various keywords I eventually hit upon an MSDN page Simulating an Error Output for the Script Component which was spot on for my needs.

Another useful MSDN page compares and contrasts the Script Task and the Script Component.

I’m currently working on an ASP.NET 2.0 application using C# and have been making use of the Enterprise Library (January 2006) from the Microsoft Patterns and Practices site.

One of the blocks we have made use of is the Exception Handling Application Block which allows us to create a consistent strategy for processing exceptions that occur in all the architectural layers.

All went well on my local development machine (Windows XP) - exceptions were happily being being written to the application event log. However, upon deployment to our development server (Windows 2003) there was nothing showing up when I opened the Event Viewer. It turns out that Windows Server 2003 permits administrators to customize security access rights to their event logs.

In order to allow the web application to write to the log I needed to add the following items:

(A;;0x3;;;AU)(A;;0x3;;;NS)

to the registry key

HKLM\SYSTEM\CurrentControlSet\Services\EventLog\Application\CustomSD

This allows authenticated users and the network service to write to the application event log. See http://support.microsoft.com/default.aspx?scid=kb;en-us;323076 for more in-depth information.

NOTE: Editing this key is discussed in a number of places on the web but one thing I found that did not seem to be mentioned was that we had to reboot the server in order for the change to take effect. We tried an IISReset but this was not enough.

Today, I decided to add a preloader to an ARP based application that I have been working on. I decided to use an external preloader to avoid the problems that others seem to be having with V2 components when they are not loaded in frame 1 (such as column headers not showing up in datagrids).

I modifed the preloader kindly provided at FlashGuru - basically I took out the first layer “fix onLoad/onData” as it stopped the onLoad function working in my main application. I also modifed the progress bar slightly. My modified version of the preloader is available for download.

As I was already using the Flash Javascript Integration Kit I needed to modify the FlashTag which loaded my application (fis.swf) from

var ft = new FlashTag('fis.swf', '600', '330', '7,0,14,0');

to

var ft = new FlashTag('loader.swf?movie=fis.swf', '600', '330', '7,0,14,0');

All seemed well until I navigated to a page in my application which had a combo box - it would not drop down. I fixed this by adding

this._lockroot = true;

to the constructor of my application view (which is the first code that is run in my ARP based application).

This fixed the problem with the combo box but now my FlashVars were not loading and the Javascript integration was not working. I managed to fix this final problem by modifying the JavaScriptProxy call from

proxy = new JavaScriptProxy(_root.lcId, this);

to

proxy = new JavaScriptProxy(_level0.lcId, this);

Basically, locking the root meant that we couldn’t reach the flash vars through _root anymore but using _level0 still works. In a similar vein, the code which tested for variables being present at initialisation needed to change from

transactionId = parseInt(_root.transactionId);

to

transactionId = parseInt(_level0.transactionId);

Finally, I have a basic (but reasonable looking) loader and the application works as it should.

Web I moved my domain a few days back I remember seeing a help message in the mail forwarding section of cPanel about how to set up forwarders that just delete or bounce messages. However, when I returned to that section today the useful help message is no longer displayed (possibly because I had added a forwarder for my wife’s email). After googling around for a good ten minutes I finally found what I was looking for.

To simply discard email to a particular address set the forwarder to :blackhole

To bounce email set the forwarder to :fail

I received an invite a few days back from Alex Beston who I met via the Brighton New Media Freelancers to join LinkedIn.

I did some research and it seems like it could be a very useful tool for maintaining existing contacts and making new ones. Here is my profile - you’ll need to register in order to view.

I’ve been convinced by Aral that I really should start a blog so here we go.

My old website was hosted by fasthosts on a windows server with ASP. In order to get this blog up quickly (and for a lot less money) I switched to a unix server hosted by a small orange which provides cPanel, Fantastico, unlimited mySQL databases and even Ruby on Rails (plus lots of other goodies) for a very small sum.

It was a breeze to install WordPress using cPanel and Fanastico and I installed the rin theme which I found at Alex Kings theme browser. The only thing I needed to change was the placement of the sidebar to the right rather than the left - which is how I like it.