Archive for the ‘Software Development’ Category

I noticed some interest in my earlier posts about ntlmHTTP, and that surprised me a bit. I wrote about the subject in 2011, and that is a long time ago, in IT terms!

So to clarify things: the ntlmHTTP project is no longer required: Adobe added NTML (aka. “Windows Integrated Authentication”) support to the CFHTTP tag in ColdFusion version 11. I did rework my code from 2011, and indeed: CFHTTP did suffice to call the Microsoft Exchange web services successfully with the credentials of a special technical account.

Although I did not test it I’m pretty sure NTLM is still there in later CF versions ;-)

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Considering the number of mobile apps dedicated to the subject I know I’m not alone in wanting to know the fuel consumption of my vehicles. Like my father, I have been doing that as long as I have driven motor vehicles on two and four wheels. Since 2013 or so I am using AndiCar (on Android): it has the features I want, and it’s a piece of FOSS (Free and Open Source Software). Keeping an eye on your fuel consumption is always a good idea, since a rise in numbers can be the first indicator of a problem with your vehicle.

When we bought a bi-fuel car, however, things got complicated. In November 2017, as far as I could tell, there were no apps that had full support for “hybrid” or bi-fuel vehicles. I had no choice but to start experimenting a bit, and I settled on testing an app called Fuelio as a possible alternative for AndiCar. I won’t do a complete comparative review of these two: let me just explain that AndiCar is faster for data entry (at least in my situation: I enter the data in the evening or in the weekend, when I’m at home, not in the gas station), and Fuelio is the better looking app.

Some of the statistics available in the apps I mentioned (AndiCar on the left, Fuelio on the right). The numbers do not correspond because the periods are different, not because of errors ;-)

So I mailed Miklós, the author of AndiCar, explaining my situation. I probably wasn’t the first one to mention the “multi-fuel problem” to him. Nevertheless I’m quite impressed with the fact that six weeks later he already published a new version of AndiCar that allows detailed data entry for hybrid vehicles like mine. To top it off, he also mailed me to tell me about the new version!

One of the advantages of AndiCar is that it allows you to define your own fuel types. I actually use three types of fuel, since we have two types of CNG in Belgium: low caloric content (L) and high caloric content (H) gas. AndiCar is perfectly capable of handling that.

As a happy person I simply had to respond to Miklós – here’s the core of my mail:

Good work, man! You impressed me with the speed with which you implemented the support for alternative fuel vehicles. I’m not just giving you last version “a look”: I have copied all the fill-ups of my new car into AndiCar, of course.

For the moment I will continue to compare AndiCar with Fuelio, if only to get a feeling for what might constitute a good solution for the “fuel consumption/efficiency calculation” issue, as you call it. The Fuelio solution is not good enough: it just uses the distance between the two latest fillings for that type of fuel. But that results in silly numbers when driving most kilometers with one type of fuel, interspersed with an occasional fill-up of the alternative fuel (and that’ what I try to do: run mostly on CNG because it’s cleaner, just switching to petrol when no CNG is available).

What is probably needed, is a system whereby it is possible to indicate for each fill-up whether it can be used for a consumption calculation based on the previous fill-up of the same fuel type. Or perhaps an extra odometer field ? Or …? I realise that my situation is different from that of people with electric hybrid cars: my g-tron runs on CNG as long as there is enough of it in the tank, and switches to petrol with an explicit warning the moment that switch happens. In e-hybrids the rules are completely different, and I have no ideas about how AndiCar (or any other app) could support such calculations – I suppose those cars can do it themselves ;-)

Oh well. I’m already quite happy with the work you’ve done, so thanks again!

PS. I ran into one issue when entering my fill-ups in AndiCar: trying to “convert” an existing entry to the new fuel type and UOM crashed the app (I tried it several times). But of course, deleting the existing entry and reentering the data in a new entry solved the issue, so no real harm done.

If only all software makers would be so friendly and so quick to react to their users!

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At work I’m busy moving all the ColdFusion applications from Windows 2003 servers with CF8 to new virtualised servers with Windows 2012 running CF11. Configuring Windows and IIS are also much more complicated than ten or more years ago, but we have that under control now. Most of the ColdFusion (and Java) code transfers without a problem, and I spend more of my time deleting scripts and components that are no longer used than modifying code.

Until this week, when I stumbled over a script that shows an inventory of the active Scheduled Tasks on the server, together with the link to their respective output (which we write to a network drive)… To do that, the code gets the data from the file, and then we put all the data in a handcrafted Query object. The names of the tasks and the links displayed fine, but there was something wrong with the start and end times: “1899-12-30” is not a time!

It took me hours to figure out what was wrong, because I was focusing on the date and time formatting functions used to format the data before adding them the query. Why the formatting, you ask? Well, we wanted to sort the data on columns containing start and end times, and in previous versions of CF our solution was to prepare the strings before adding them to the Query – seemed like a good way to make sure that ‘11:00:00 AM‘ and ‘11:00:00 PM‘ turned up in the right place of a sorted column.

So what was wrong with our code? Let me quote the “Query of Queries user guide”:

If you create a query object with the QueryNew function and populate a column with date constants, ColdFusion stores the dates as a string inside the query object until a Query of Queries is applied to the query object. When ColdFusion applies a Query of Queries to the query object, it converts the string representations into date objects.

Our code added strings formatted as “hh:mm” to the Query object, but once we filtered or sorted that Query using QoQ those columns were transformed into datetime objects. ColdFusion 11 then adds that time to the default date used, i.e. “1899-12-30“.

Clearly, that was not the case in earlier versions of ColdFusion – at least not in CF8. There are multiple solutions to solve this problem, once you know what’s going on – so now our overview displays everything as intended.

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I’m currently trying to automate the creation of datasources in ColdFusion server instances, in order to facilitate a number of migrations our machines and applications have to go through. For the record: this turns out to be reasonably simple, once you get the knack of using the ColdFusion Administrator API classes (if I find the time, I’ll write about that later).

One thing slowed me down: a typical error message without much meaning. This is what I received when recreating (or at least trying to recreate) an Oracle RAC datasource:

java.sql.sqlrecoverableexception: IO Error: NL Exception was generated

I wonder why developers often invent error messages that do not tell us what really went wrong. In this case, it turned out that I forgot to copy a single closing parenthesis at the end of the JDBC connection string. Let’s call that a syntax error, Oracle, and please give a significant message if I mess up! Or is it Adobe’s ColdFusion that is hiding more explicit and clear details about what went wrong?

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I appreciate the fun one can have at building programs and tools that do something thought to be impossible. Running Java code on a Commodore C64 is such a project.

Back to the Future Java (b2fJ) aims at bringing the power of Java to 8-bit home computers of the ’80s. This project provides a toolchain to cross-compile Java programs under Windows.

You’ll find everything about “b2fJ – Back to Future Java” on Github.

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The language isn’t new: Kotlin was created more than 5 years ago by JetBrains engineers. A preview version was released in 2011. Kotlin is a statically typed programming language for the Java Virtual Machine (JVM). Being crude, you could say that it’s “just another” enhancement of the Java language, just like Groovy or Scala. Nice, but hardly indispensable.

But Kotlin made a name for itself in May 2017, when Google announced “that it is making Kotlin […] a first-class language for writing Android apps” (in the words of Frederic Lardinois on TechCrunch). The Wired website has a bit more info on why the language was developed and why it is so “hot” these days. And the article concludes:

And its applications extend well beyond Google’s platform. Like Java, it can be used to write apps that run on desktops and servers as well. Plus, JetBrains has released tools for translating Kotlin code into code that can run on iOS or even in web browsers. All of which is to say, you can expect to find yourself using apps written in Kotlin more and more often in the coming months and years.

I have not yet written a line of Kotlin, but perhaps I should try that sooner rather than later. Since I’m also looking at Apple’s Swift language, the combination of learning both could be beneficial… or problematic, since someone asserts that both are quite similar (but not the same, of course): see “Swift is like Kotlin” for details.

I still would like to know how the name “Kotlin” was chosen…

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Of course I’m going to try this out: “Huzzah, Visual Studio for Mac is now available to all“!

Click the image to see more details about the product

Click the image to see more details about the product

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Last weekend, I spotted two old BMW motorcycles on the road in the port of Antwerp (Belgium). I had my camera in my hands, so I managed a few badly-framed photos – you can see them on Flickr.

By chance, I also spotted an advertisement for a similar bike. I don’t pretend to be a specialist on the subject, but I haven’t seen many BMW R50/2’s in this color scheme (not even on Google Images), and I find this combination quite flattering!

A fine-looking oldie, as seen in one
of the last advertisements on Kapaza

When I said I found this “zoekertje” by chance, I meant that I just had a quick look at the Kapaza website, because the site announced just last week that it will be closing down in a few days. I have visited that site, with its thousands of advertisements for second-hand stuff in many categories, while on the prowl for say another bike or a special lens for my camera. Kapaza is (was) one of the few big Belgian websites that used ColdFusion for at least parts of its site, and that made me pay a bit more attention to it also. This is one more website that won’t last half a century and more, unlike the motorcycle shown here!

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Last week, I did loose a lot of time in what should have been a quick ColdFusion hack. My colleagues and I were just trying to set up a web service-based solution for a simple problem: they had a JavaScript page that needed a bit of data for which I already had the code in ColdFusion. So I created a new directory in an existing application, whipped up the required code in ‘index.cfm‘ to return a bit of JSON and tested the result from my browser… only to get an “Error 500 - Application index.cfm could not be found“.

Weird, heh? The required file was there, so why could CF11 not find it? Adding an ‘Application.cfm‘ did not help, neither did repackaging the code in a CFC. On CF8, on the other hand, everything worked as expected. So what was going on?

It took some time, but I did find the explanation: CF11 reserves the directory name ‘api’ for special treatment, so you can’t use it like any other directory name – and of course that was the name I had chosen! Adam Tuttle described the situation nicely in 2015:

Funny you should mention that the issue is inside an /api folder. I’m trying to track down the same problem, except I’m directly accessing an index.cfm (sort of — onRequest intercepts the request and redirects to CFCs as appropriate — it’s a Taffy API) and I’ve found that renaming the folder from /api to … literally anything else… works fine. It’s almost as if something in CF has special meaning at /api, like the special /rest mapping does.

Indeed, renaming my directory solved the problem – too bad it took me so long to find the cause. On to the next problem!

PS. Adam Tuttle has more to say on the subject, but his post on the subject has disappeared: the URL ‘http://fusiongrokker.com/post/coldfusion-11-sometimes-chokes-on-api‘ no longer points to the relevant text, but is redirected to another blog also belonging to Adam Tuttle. There, unfortunately, the post is NOT available. I won’t call this a case of linkrot, but it’s not good either. Luckily, the Wayback Machine has a copy of the page, including a few comments…

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Brent Simmons isn’t a new name in this blog – I have cited his name several times since 2001. A few days ago he wrote:

It’s been years since I could build the Frontier kernel — but I finally got it building.

The high-level goal is to make that tool available again, because I think we need it.

The plan is to turn it into a modern Mac app, a 64-bit Cocoa app, and then add new features that make sense these days. (There are so many!) But that first step is a big one.

“Frontier Is Interesting”, says Jim Roepcke – click to see what he writes

It’s an interesting development, from several viewpoints. I wrote some of my first “web applications” in Frontier, and that makes that Frontier will always have a special place in my book of tools. It’s also nice to see a relevant piece of software evolve so that it continues to run on modern hardware and OS’s. At some point, I will certainly download and run a copy on my Mac.

But the question is: do I want to go back to developing stuff in Frontier? Do you want to?

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It’s something I need to remember: how do I install an old PyUSB package on Xubuntu (or a similar Debian-based OS). Why, you ask? Because I need that old version 0.4.3 for the little script that reads the solar energy numbers from the SMA Sunny Beam.

Image of the SMA Sunny Beam monitor for our solar panel installation

The SMA Sunny Beam monitor for our solar panel installation

Luckily, it isn’t too hard to do. This is my context:

Step one is to make sure you have the required header files to compile the PyUSB package. So you open up a terminal session and execute

sudo apt-get install libusb-dev
sudo apt-get install python-dev

Step two: Extract the root folder and all the files from the PyUSB archive, and make that folder your current directory in the terminal session.

Step three: compile and install the package with this command:

sudo python setup.py install

That’s it. When all goes well, you’ll be able to verify the existence of two new files on your system, in a directory called “/usr/local/lib/python2.7/dist-packages“:



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More than 8 years ago, I wrote about the Google App Engine as a platform. Much as I liked the concept, I also remarked that it would be… great to have a complete development environment within the browser, coupled to a runtime.

Turns out that Fog Creek, the software company founded by Joel Spolsky, has built just that: “a developer playground for building full-stack web-apps fast“. It’s called Gomix – but it was called HyperDev during the development of the product. That ties in neatly with my reference to HyperCard as an example of a simple tool that allows anyone to built the tool she/he needs. Nice work, Joel !

So here it is, my first “app” in Gomix (just for fun and with lots of tongue in cheek):


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The InterWikiLinksPlugin, my small addition to JSPWiki is part of the JSPWiki source tree (or at least it was somewhere in 2009). But Pikacode managed to lose the version I installed there, so I am storing it for posterity on this site as well ;-)

Click the image to download the PDF

Click the image to download the PDF

I had to package it as a PDF file here in WordPress.com, but just copying the text content of the file and saving it as a Java file in the JSPWiki Plugins source directory should suffice for a successful compilation.

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I just spent yesterday afternoon debugging a somewhat older ColdFusion+JavaScript application: some of the administration functions were not working. A partial explanation for my time spent on the issues is that the application was developed in the days of Internet Explorer 5. We’re still running IE6 on a substantial number of the several thousand PC’s in use in the company… in combination with an older version of Chrome. So refactoring the JavaScript code (to make it work in both browsers) was part of the ‘fun‘.

In the end, the real cause of the core problem I encountered was to be found in a few SQL statements that I had neglected to check out, wrongly assuming they had been working in the past. The reason they continued to slip under the radar was simple: the original developer had managed to “hide” that SQL code in a <cftry> statement with an empty <cfcatch>. So there was nothing in the logs, of course.

From the OWASP website

From the OWASP website

Finding the root cause reinforced a lesson I had learned a long time ago: only catch exceptions if you’re going to do something serious and meaningful with them. No, swallowing them whole isn’t meaningful. OWASP summarizes: “Swallowing exceptions is considered bad practice, because the ignored exception may lead the application to an unexpected failure, at a point in the code that bears no apparent relation to the source of the problem“.

This story teaches a second lesson as well. In the future, I will scan code for exception swallowing situations before I start debugging – that could have saved me a lot of time today!

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Ray Camden wrote about the CF log file enhancements in CF9 a few years ago: “CF901: Logging enhancements“; among other things, he explained the possibility of disabling and enabling logging into particular log files. This is supposed to work in exactly the same manner in CF11. Since then this theme wasn’t discussed much. That’s too bad, because I have a strange problem in CF11, and there are no clues to find on the internet.

Here’s my situation:  I accidentally disabled a custom log file for a Scheduled task, and now I can’t find a way to re-enable this log. I tried hijacking the “disable” link by replacing it with “enable”, but that did not work – not even after a restart of ColdFusion.

I needed some time to figure out that I could go on with my work again by renaming the .cfm file as well as the log file, but that does not really count as a solution. So all advice to get this specific log back to work will be appreciated!

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