Drupal

When developing plugins in Drupal a common task is to inject context so that certain tasks can be performed.

For example, we might have a block plugin that needs to know about the content entity of the page it is currently being rendered on. We could potentially inject the routing system into the plugin and use this to find the currently loaded entity, but there is a drawback to this. There is a fair amount of custom logic involved in finding the content entity from the route and we would need to use this same code every time we want to solve this problem.

This method also hard codes the route into the plugin and so makes it difficult to select any other sort of context. There is also a problem when it comes to caching as you also need to inform the plugin about the use of routing so that the caching layers know how to cache things.

Whilst working on a module I found that I needed to do something that was difficult to find information for. I think part of that is because the solution is simpler than I was thinking, but it did cause me to get lost in source code and internet issues for a while.

What I needed to do was to load in a list of configuration entities that matched certain parameters. The configuration entity I was dealing with was used to manipulate the output of a form, but only if certain conditions were met first. I thought that this information might be useful to others who are looking to load configuration entities.

I have been using the Drupal dependency injection system for a while now, even giving talks and writing articles on the subject. As the release of Drupal 10 is just around the corner I have been thinking more about how to override dependencies to plugin classes.

I wanted to share a trick to overriding dependency injection that will make your life easier. The Drupal codebase itself does not use this trick, but it seems that many contributed modules have started to use this trick to create plugin classes.

In this article I will go through how to add dependency injection to Drupal classes in two different patterns.

Drupal has a number of coding standards and best practices that govern the way code should be written. This has many benefits but can allow for a consistent and maintainable code to be created.

All Drupal modules and themes are written with coding standards in mind and that allows Drupal developers to look at any project and see a similar style of code. If you ever submit code to Drupal or a contributed project you will be required to adhere to these coding standards, so it makes sense to get used to knowing about them.

The main tool that is used to test coding standards in Drupal is PHP_CodeSniffer, which is a widely used static analysis tool for testing PHP coding standards. It comes with a set of coding standards built in, but it is possible to add the Drupal coding standards for the tool to use.

Ajax Dialogs in Drupal are a good way of presenting content to a user without them having to navigate away from the page they are looking at.

This is useful when presenting a list of items or a link to something like a terms and conditions page. Users can click a link and view the content as a dialog box.

Creating dialogs in Drupal is built into the platform and are powered through the jQuery UI dialog component.

The content moderation module in Drupal core is a powerful way of allowing content to pass through a moderation workflow. This allows you to create workflows that take content from draft modes into a published state and back again.

Each content moderation state can have a "published" setting that tells Drupal if an item of content in this state should be considered as published. This means that if a page of content is put into a published state then users with the "view published content" permissions can view it.

Users would need the opposite permission "view any unpublished content" to be able to see a content in a state without this flag set.

Creating services that listen events in Drupal is pretty straightforward; you just need to create and register a service class and let Drupal know what event you want to trigger on.

Altering routes in a Drupal site is also done through an event trigger, but in this case the implementation is slightly different. This is because Drupal takes care of the trigger setup and allows you to create an event subscriber that will automatically trigger when the routes are created.

A while ago I wrote about including oEmbed providers in a Drupal site and briefly touched upon creating custom providers. I didn't go into any more detail there so I decided to write another article looking at creating custom oEmbed providers.

In this article I will cover what oEmbed is and how to set up a custom oEmbed endpoint. I will also then go onto show how to setup and configure a Drupal site to consume that custom oEmbed endpoint. 

Last week I visited the city of Prague to attend the European DrupalCon 2022. The event was held between September 20th and 23rd, and was attended by over 1,200 people.

This was my first physical conference since DrupalCamp London 2020, and the first DrupalCon I have attended since DrupalCon Dublin 2016. Despite the worries about covid I was still pretty excited to attend the event. I arrived on Monday night and as the event didn't start properly until Tuesday afternoon it gave me a small chance to explore the city of Prague before the conference started.

Client requirements can be complex and those complex requirements often require custom code to be written. This includes making sure that the editing process conforms to certain validations.

Drupal can easily handle simple validation like having a value in the field or making sure an email is valid, but with more complex validations usually require custom code.

Whilst it is possible to inject custom validators into form submissions, I find using validation constraint classes makes the whole process much more predicable. Also, validation constraints are applied at a lower level than form validations, which means we can validate the data is correct even if we are creating the entity from an API.