Working with logic surrounding dates can sometimes be difficult and it's fairly common to come across really subtle date and time based bugs.

I was recently shown a bug in a PHP application that looks like it should be working at face value, but doesn't actually produce the correct result.

The issue in question was surrounding a date comparison. A collection of objects containing dates were compared in order to find those dates that were less than a month old. This worked fine in testing since all testing dates were less than a month old. After the system was in use for a number of months it became clear that the check wasn't working so further investigation was needed.

I recently had this idea for a new Drupal module that allows users to manage their sessions. The idea is that a user could look at their current sessions to see if any suspicious activity had happened on their Drupal account. They could then delete any sessions they don't like the look of in order to kill off that session.

The functionality I describe here is actually quite important as it allows users the ability to spot suspicious activity on their accounts. I have even used it in the past when one of my accounts was hacked. The fact that the session was opened from Brazil helped me inform the site that something was wrong.

I did some searching on Drupal for a module that did the same but didn't find anything so I thought I would create a module and go through the process of creation in an article. This includes the research into how this can be achieved in Drupal, looking at designing the interface, and then adding code to create the needed effect.

I was talking with a fellow programmer the other day about a poor test that we were reviewing and we got onto the subject of what makes a poor test. The test in question had a reliance on a previous test being run, and the problem we encountered was that on some systems the dependent test was run after this test, which caused it to fail.

This also caused some headaches in local development as it couldn't be run in isolation. We had to ensure that both tests were run, in the correct order.

After fixing the tests so that they could be run independently I created a list of some common problems that programmers might come across when writing tests. These rules can be applied to most coding test, not just unit tests or behavioural tests.

If you are working on the Linux command line then sometimes you'll do a search to find out how to run a command that performs a task. I don't usually copy and paste commands in unless I can see what is going on, which used to mean spending time going through man pages and documentation trying to find out what this or that flag does.

That all changed when I found explainshell.com, which will extract the parameters of a command and tell you all about what the different flags will do.

Reflection is used to gather more information about code during the runtime of the program. This allows code to inspect itself and to make small modifications, which is useful in a variety of situations.

This is possible in PHP thanks to the reflection classes, which are built into core. PHP is capable of using reflection to inspect all types of classes, object, functions, variables and even the recent addition of Fibers. Using the reflection classes we can find out the internal structure of a class that an object is part of, including properties, methods constants as well as what sort of class we are dealing with. Reflection works even if the property of method is private or protected.

This post will concentrate on objects (and their associated classes) as the code used to inspect objects can generally be applied to other forms in PHP.

I use sites like CodePen and JSFiddle all the time to write JavaScript and CSS, but I've not seen a similar site for writing PHP applications. I have used 3v4l.org to test small scripts using different versions of PHP, but it doesn't allow dependencies to be added and doesn't have a nice editing interface.

Recently, I found a site called PHPSandbox that allows users to create PHP applications that can be run in the same way as applications on CodePen. This includes using composer to inject dependencies into the application and a nice little editor interface to see the output and logs from the application.

2022 marks 20 years since I started my MSc in computer science degree at the University of Aberystwyth. So, I thought I would take a look back at my thesis for the degree and see how far I have come since then.

The title of my thesis was "Using The Java3D API To Visualise Molecular Compounds". I used a system called Java3D to create ball and stick models of molecules. A second requirement was to allow the application to compare two molecules together.

The course I did was known as a conversion course and was designed to compress the three years of the undergraduate computer science degree into a single year, along with an introduction to Java programming bootcamp the summer before the course started. This was a year of hard work with 12 hour days and weekends of constant study. The drop out rate for the course was about 80%, with most of that being in the first few weeks.

Adding a progress bar to the top of the page is a simple way of showing the user how far down the page they have read. There is a scroll bar on the right hand side of the page on my current device, but that isn't always present on all devices. It is possible to hide the scroll bar on Macs and mobile devices so that they are only shown as the page is being scrolled.

Putting this piece of information at the top of the page can be a useful indicator that augments already existing technologies.

Drupal 9.3.0 came with a new feature called entity bundle classes. This allows more control of entity bundles within Drupal and provides a number of benefits over the previous mechanism of using hooks to control everything.

Drupal makes extensive use of entities to manage content and configuration. User details, pages of content and taxonomy terms just a few of the things that are represented in a Drupal site as content entities. Different types of similar configuration are called configuration entities, which would include things like text format settings or even date formats.

Content entities are normally fieldable, and in the case of content types and taxonomy terms Drupal allows users to generate their own variants. These different variants of entities are called bundles. Entities define the types of objects found in a Drupal site, bundles represent the different sub-types of these entities.

Inspired by a YouTube video I saw on awesome Numberphile channel about how to draw hitomezashi stitch patterns I decided to recreate them in Python with the aid of the Tkinter Canvas element. The pattern is quite simple and is an example of simple rules creating complex patterns, which I have an interest in.

The idea behind hitomezashi stitch patterns is to take two sets of numbers and draw lines on a grid. One set of numbers is the horizontal and one set is the vertical lines of the grid. The lines drawn are dashed but the key difference is that each start of the line is offset from the start depending on a certain factor. In the video Ayliean MacDonald uses letters of a phrase and offsets the start of the line if the letter is a vowel. She also uses the numbers of pi and offsets if the line if the number is odd.