PHP

Generating Colour Palettes From Images In PHP

4th August 2024 - 11 minutes read time

A common web design pattern is to incorporate an image into the design of the page. This creates a tighter integration with the image and the rest of the page.

The main issue in designing a page around the image is that the colours of the page must match the image. Otherwise this creates a dissonance between the image and the styles of the site.

In this article I will look at extracting a colour palette from an image so that it can be used in the design of a web page.

Validating XML Files With XML Schema Definitions In PHP

21st July 2024 - 10 minutes read time

XML is a useful format for configuration, data storage, and transmitting data from one system to another. As a human readable format that can be easily read by machines it quickly gained favor in lots of different systems as a mechanism for data storage.

Many systems transparently make use of XML without the user ever seeing it. The API system SOAP is built around XML data, and it is normally possible to ask API endpoints to respond in either JSON or XML. It is common to see XML files used in configuration of systems as they can be easily edited and parsed when needed.

Creating A Character Bitmap In PHP

23rd June 2024 - 13 minutes read time

I was watching a video from NDC by Dylan Beattie the other day on The Story of Typography and a particular section stood out to me.

The talk ranges from the initial start of writing symbols to the formation of typography as an art form and the creation of eInk displays. Well worth a watch if you have some time to spare.

The part that was interesting to me was then discussing early word processors and the ASCII character standard. Early word processors couldn't store the amount of data required to fully render a font, so characters were rendered using a bitmap system.

Approximating Pi Using A Circle And A Square

26th May 2024 - 7 minutes read time

Pi day was a few weeks ago, but I came across this simple approximation of pi recently and decided to put together an example in PHP since it seemed pretty simple.

This approximation of pi centers around a real world example, but we can simulate this using some code.

Let's say you have a dart board that fits inside a square area so that it is flush with the outside of the square. Then you pick someone who is particularly bad at darts and get them to start throwing darts. Record where the darts hit and after a million or so darts you will have a number of darts that hit the board and a number of darts that hit the background.

Drawing A Parabolic Curve With Straight Lines In PHP

12th May 2024 - 16 minutes read time

A parabolic curve is a type of curve where every point is an equal distance from a focal point. There a number of different way to generate this sort of curve using math, but one of the simplest is to use straight lines to create the illusion of the curve.

The curve is created by diving two axis into equal points and then drawing a line from the first point on one axis to the last point on the opposite axis. Each line of the curve is drawn in the same way, repeating the process of drawing a line between opposite points for every point along the axis.

Recreating Spotify Wrapped In PHP

17th March 2024 - 15 minutes read time

I quite like the end of the year report from Spotify that they call "Wrapped". This is a little application in which they tell you what your favorite artist was and what sort of genres you listened to the most during the year. It shouldn't come as a surprise to me that I listened to this or that, but since I listen to Spotify around 30-40 hours a week I certainly lose track of what my favorite artist was that year.

This years report got me thinking about how difficult it would be for me to generate my own Spotify report, whenever I wanted. Maybe to see who I had listened to the most during the week, or what sort of genres I was into at the moment.

Should A Constructor Throw An Exception?

18th February 2024 - 8 minutes read time

Let's say you had a class that you wanted to use, but there was some sort of error in creating the object. This might be that the wrong parameters were passed, or the third party service (eg. a database) wasn't available at the time of creation.

If this happens you'll obviously want to handle the error correctly, but the question is would you throw an exception in the constructor or handle the error condition elsewhere?

Note that this article will talk about PHP, but the same discussion applies to other languages that implement OOP principles.

PHP Question: Variable Reference

10th December 2023 - 9 minutes read time

Question

What does the following code print out?

function arrayPrint($array)
{
   echo implode(' ', $array);
}

$arrayA = [1, 2, 3];
$arrayB = $arrayA;
$arrayB[1] = 0;
arrayPrint($arrayA);

Creating An Authentication System With PHP and MariaDB

15th October 2023 - 36 minutes read time

Using frameworks to handle the authentication of your PHP application is perfectly fine to do, and normally encouraged. They abstract away all of the complexity of managing users and sessions that need to work in order to allow your application to function.

That said, it is important to take a step back and understand how authentication works in PHP. This allows you to more accurately debug problems with framework authentication systems that you make common use of.

Creating an authentication system using PHP is pretty simple since PHP has many of the features and functions built in. In fact, frameworks will simply wrap this feature set into a coherent authentication model that can be expanded to introduce new features.

In this article I will go through the steps required to create an authentication system using PHP and MariaDB. I will assume you have some knowledge of PHP, but that you want to know more about how to authenticate users.

Creating Sparklines In PHP

17th September 2023 - 12 minutes read time

A sparkline is a very small line graph that is intended to convey some simple information, usually in terms of a numeric value over time. They tend to lack axes or other labels and are added to information readouts in order to expand on numbers in order to give them more context.

Sparklines tend to be around 20-30 pixels height and up to 150-200 pixels wide. The are generally best when you want to show between 5 and 15 items as adding more items to such a small graph can make things a little messy.