The Blog of Jonas Martinsson

As I was mentioning in an earlier blog entry , the part of the FeedJournal project which I have been feeling most insecure about is how to design the algorithm for laying out the articles in the newspaper. This is a critical step for a number of reasons: it has to look like a newspaper, it has to read like a newspaper, and it has to be pretty (the output PDF is essentially a part of the FeedJournal GUI). Anyway, I am happy to report that significant progress have been in this area. I developed an algorithm which dynamically creates a newspaper with customizable: number of paragraphs margins paper size font spacing between rows and various article elements I have also implemented support for a headline font size which is a function of the article's importance/size . Together with the mas...

So I got up at 4:30 today in order to get some serious work done on FeedJournal before going to work or the baby wakes up. Well that was my plan at least. The first part went fine; I got out of bed, went for a short run and showered. By then the baby was awake though so I had to do some multitasking with one arm holding the baby, while the other hacking away at the keyboard. But that's actually much nicer than it sounds. Seriously. Pretty soon I run into problems with my SQL database that has been working flawlessly until now. Whenever I tried to connect to it I was thrown an SqlException: "Failed to generate a user instance of SQL Server due to a failure in starting the process for the user instance. The connection will be closed." At first I thought it was due to an incorrect connection string but everything seemed fine and the database was in the right location. ...

I have been sick with the flu for the last week and still don't feel so great. For this reason the programming hasn't really proceeded as I expected. However, I have been doing a lot of thinking in my head about the database and class designs. As soon as I feel better I will work on laying out the PDF newspaper dynamically, which I realize will be a tough nut to crack. Basically the problem is related to the classic computer science problem of bin packing, which is NP-complete. NP-complete is a computer science term, standing for "non-determinis tic polynomial time". It basically means that there is no simple solution to the problem. My approach will be to take some shortcuts and make compromises so that the layout will be acceptable from a design viewpoint, while not digging myself into a hole with a too complex layout algorithm In the meantime, while w...

FeedJournal , like any RSS aggregator, needs to be efficient when it is updating the list of subscribed feeds. It is obvious that a sequential polling of feeds (check each feed and proceed to the next after finishing with the previous) will be sub-optimal in terms of performance and user experience. The internet requests will need to occur in parallel for optimal performance. However, if your feed subscription list contains more than a trivial amount of feeds, you don't want to congest your Internet line with all of these request at the same time. IE7's RSS infrastructure calls this throttling, and it limits the number of concurrent web requests to 4. I don't see a reason to differ from this approach and implemented the same system. One of the great things about .NET 2.0 is the easy-to-use infrastructure for multithreading and thread synchronization . By just ...

One of FeedJournal's system requirements is to be able to customize the fonts in the PDF newspaper. Honesty I thought that this would be a piece of cake. But, I run into some problems... In the PDF file you can specify Type 1 and Type 2 fonts. Type 1 are common fonts, such as Courier, Helvetica and Times Roman. Adding these fonts are very straightforward since the PDF format supports them natively. However the difficulties begin when the user should be able to select any font. The Type 2 fonts have to be specified using an absolute path to the font (which can be either TrueType or OpenType). No problem right? Yeah, that's what I said yesterday too. I tried to simply add a FontDialog to my settings form. From the control I wanted to get the selected font's absolute path. No dice... No matter how hard I looked for the suitable property in the .NET's Font c...

Reading my fellow finalist Douglas Steen's entry about bug tracking tools, I am totally agreeing with him that it would be great to have a lightweight bug-tracking tool built into Express. Sure enough, we have the Task List pane where tasks can be sorted and having a priority but that's not really accomplishing anything substantial. Douglas chose a web-based bug tracking system and he mentioned another web-based system. Hunting the Internet will lead you to yet other web-based systems. Why does 99% of bug-tracking systems have to be run in the browser? I hate the browser: it is less responsive than a native Windows application as well as usually lacking a menu and having quirky keyboard support. Just because a system is multiuser doesn't mean that the browser is the only interface. The large advantage I see of using the browser is that no client softwa...

I have started the implementation of my project in C# Express Edition, and one of the first things I have stumbled upon is the frustration of having to deal with many different XML feed standards. There are RSS and Atom, each of them with several different sub-versions. But that's not all. We also have a slew of Internet cowboy hackers who don't have any desire at all to follow these standards. In short, RSS/Atom land is a jungle. Time to take out the machete! When researching the options of a suitable machete for the feed jungle, the following 3 caught my attention: Atom.NET + RSS.NET IP*Works Microsoft's RSS library , included in IE7 Rolling my own component based on .NET's XML support Atom.NET + RSS.NET These are two separate open-source libraries, implemented in C# .NET, which enables user...