Color Sorting In PHP: Part 5

3rd November 2019 - 11 minutes read time

Since my last visit to this subject I have been thinking about how to represent a collection of random colors so that it looks sorted and that no information is lost during that process. I quickly realised that I needed to use all three aspects of the color space, which lends itself to generating 3D objects. Indeed, the red, green, blue color space is built around a cube so it can often be represented as a cube.

The hue, saturation, and value color space is built around the concept of a cylinder, which means that 2 of the axis lend themselves to a circumference of a circle (the hue) and the diameter of a circle (the saturation). This is an example of the polar coordinate system. We can therefore draw a circle using hue and saturation and the value can be used to represent a different aspect of the color space.

Drawling A Circle With Pixels In PHP

30th October 2019 - 9 minutes read time

Since my last post, where I talked about drawling a line with pixels in PHP, I have been looking at drawing circles. As it turns out, there are a few different ways to draw a circle, so I'll go through a few options here.

To start with, there are some built in functions in PHP that can be used to draw an arc, circle or ellipse as a filled in shape or a line. The built in function in PHP called imageellipse() that can be used to draw a circle. This is part of the GD library.

Drupal 8: Prevent User Role Elevation

25th October 2019 - 4 minutes read time
Drupal has a little flaw in its user permission system that allows users to give themselves, or other users, roles that they shouldn't be able to. If the user has the 'administer users' permission this essentially gives them access to alter roles for any user on the system, meaning that they can grand administrator access to any user on the system. The fix to this involves a couple of actions.

Too Many Open Files Error In PHP SoapClient

21st September 2019 - 4 minutes read time

Whilst working on a project recently I hit upon a PHP error that I've never seen before. During a process where a soap service was calling an API the connection would fail and the program would fatal error and stop.

I had protection mechanisms in place to catch this kind of connection error, but the fatal error was caused when the program tried to throw the exception I had put in place to indicate a failed connection.

Here is the error message (with some of the detail removed). This is a Drupal site but that detail is irrelevant to the problem.

Drupal 8: Running A Batch Through An AJAX Request

20th September 2019 - 7 minutes read time

This problem came out of a recent project I was working on. I had to perform a bunch of API lookups on behalf of a user that could take a minute or so to complete. The results of the API lookups were cached and so once it was done the site would be very quick, unfortunately the initial API lookup slowed down the page load quite considerably so this created a problem.

Rather than just doing the API loading in the page load process and making the user sit through it I created a batch process to load the API results in a more manageable manner. This created another problem as although the batch runner in Drupal is really good, it is perhaps a little too much just to show to users and expect them to understand what is going on. This led me to think if I could run a batch process via an AJAX callback from the page they were trying to load.

Drupal 8: Custom Cache Bins

14th September 2019 - 10 minutes read time

Drupal's cache system is robust, feature full and extensible. It can be used to cache small blocks of rendered output or the results of more complex calculations. The cache can be stored in a for the page request, in a database or in a different cache system.

I recently needed to store a decent amount of data that was pulled from an API. Getting the data from the API took a few seconds so it was important to cache this within the site for quick retrieval. Even just storing the cache in the database was many times quicker than the API so it made sense to cache the results within the site. Having the user sat there waiting for the page to load every time they do anything isn't great.

To this end I created a small Drupal service that would manage this cache for me. Here is the record from the services YAML file within the module.

Creating A Language Cascade In Drupal 8

14th March 2019 - 19 minutes read time

From the pages of 'crazy things you can do with Drupal 8' comes this idea that I recently had to implement on a site. This was on a site that had implemented translations, but they needed something a little extra. The central idea was that if you visited a page on the site in a particular language, and that language didn't exist, then to try and give the user a similar language.

If you weren't already aware, Drupal's default behaviour is to return the default language version of a page if the language requested doesn't exist. If the Path Auto module is installed (which is usually the case on most Drupal sites) then Drupal will not be able to translate the path alias correctly and will issue a 404 if the requested translation doesn't exist. Drupal can't take the path for the French page /fr/about-us and find the original node because as far as it's concerned /fr/about-us doesn't exist.

DrupalCamp London 2019

4th March 2019 - 8 minutes read time
On the weekend of 2nd and 3rd March I went down to London to attend DrupalCamp London 2019. This weekend I went with 9 other colleagues from Access, which is almost certainly our biggest company outing to a camp.

Drupal 8 Messenger Service

7th February 2019 - 2 minutes read time

For a long time the drupal_set_message() function has been a mainstay of Drupal development. You can use this function to print a message or an error response to a user. This is useful to do as it can be done almost anywhere before the final page rendering functions and will be printed into the same area of a Drupal page.

This has recently been deprecated in Drupal 8.5.0 and so I was looking around on how to do the same thing in a new way. Drupal now has a messenger service, powered by the class Drupal\Core\Messenger\Messenger. This can be included into your code using the following shortcut.

PHP:CSI - Random Increment Insert

26th January 2019 - 7 minutes read time

A while ago I was working on some changes to a website and came across a block of code that made me stare blankly at my screen. The website I was working on was a custom build website, created by another developer at the company I was working with at the time. I have never done a PHP:CSI on this site before but remember being so amazed at what I found at the time that I made a note of it for future reference. I have pondered recently how to approach the analysis of the code.

The code I found was in a method that inserted an item into a database table. For some reason that I can't fathom the developer had opted to not use auto increment ID's and has instead developed a method that essentially randomly decided on an ID number for the item.

I can't paste the entire block of code here, but I can include the region of code that made me scratch my head in bewilderment.