Drupal media entities are fieldable entities, which means that you can add any custom fields you want to your Media types. These fields can be used for collecting additional metadata about a resource, categorizing and organizing resources so they're easier to find in a large media library, or for displaying information like a photo credit or transcript for a video. The possibilities are endless once you know how to add, and optionally display, fields in Drupal.

Some example use cases for adding fields to Media types:

• Collect, and display, a credit to go along with a photo. This could also be a date, a location, or any other metadata.
• Store resource width and height dimensions as custom fields so they can be referenced by display logic in the theme layer.
• Use Taxonomy reference fields to add tags or categories to help keep a large library organized.

In this tutorial we'll:

• Learn how to add fields to a Media type
• Verify our new custom field is working

By the end of this tutorial you'll know how to add custom fields to any Media type.

In this exercise, we'll practice using the t filter in a Twig template. As a best practice, all hard-coded text in a template should be translatable. Simple text (containing no dynamic tokens) can be passed through the t filter to achieve this objective. Along the way, we'll also use a basic conditional if statement with Twig. We recommend that you try following the exercise's steps first, and refer to the video if you need help.

Drupal core comes with a few base themes: Stable, Stable 9, Classy, and Stark. Each one has a different intended use case. And all of them are useful as a reference for building your own themes.

In this tutorial we'll:

• Learn what each of the base themes included in Drupal core is intended to be used for
• Compare the output from the base themes with a focus on Stable and Classy

By the end of this tutorial you'll be able to explain the use case for each of the base themes included with Drupal core and make an informed decision about which, if any, to use when creating your own custom themes.

The available dynamic tokens or variables vary from template to template. Each page is built from a set of templates.

In this exercise, we'll:

• Override and name the node template file so that it will only affect Article nodes on our Drupal site.
• Inspect the available variables.
• Customize the markup.
• Use the Twig filter without.

We recommend that you try to work through the exercise yourself, and refer to the video if you need help.

It's time to create the bare-bones structure for a new theme on your site. You should try to complete this exercise based what you've learned from the tutorial prerequisites listed below. The video at the end of this tutorial will walk you through the implementation of this exercise if you need some help. In this exercise, we'll:

• Create an info file that describes a custom theme to Drupal with the regions listed below (we're going to name ours "reboot").
• Enable, and view, a bare-bones custom theme.

By the end of this exercise, you should feel comfortable starting a theme using several methods.

Stark is one of the themes bundled with Drupal. It is intentionally bare bones and its purpose is to help Drupal theme and module developers get to the heart of Drupal's system templates. In this tutorial, we'll explore Stark and its primary features and discuss the various reasons for utilizing the Stark theme.

Themes define the regions that are available for site administrators to place blocks in, creating a layout framework within which the components that compose a page can be placed. As a theme developer you'll need to determine what regions are necessary to accommodate your design's layout, while also ensuring it'll work with the way Drupal uses blocks to place content onto the page. Deciding what regions to create requires knowledge of how Drupal works and a clear vision of the design you're trying to achieve.

In this tutorial we'll:

• Explain what regions are and how they relate to themes
• Describe how regions are handled internally within Drupal
• Demonstrate things to keep in mind when planning the regions for your custom theme

By the end of this tutorial you should be able to describe what a region is, explain how Drupal themes use regions to place content, and get started dissecting your own designs into regions.

As we learned in the What Is a Breakpoints YAML file? tutorial, modules and themes can expose their site's CSS breakpoints and media queries to other Drupal modules and themes by implementing a breakpoints YAML file. In that tutorial, you also learned about the structure of a breakpoints configuration file and why you'd want to create one. In this tutorial, we’ll walk through the process of creating an example breakpoints file step-by-step.

By the end of this lesson, you should be able to create a working breakpoints YAML file in a theme or module. We'll test it out by enabling Drupal's Responsive Image module, where we'll be able to see it listed in the configuration form for creating a new responsive image style.

Drupal comes with all of its caching features enabled by default. This improves response time, but can be frustrating for themers as it makes it harder to preview the changes you make to template files.

In this tutorial we'll look at:

• Why these features are enabled by default
• How the theme layer leverages Drupal's caches
• Why you should learn to disable them when doing development

This tutorial demonstrates how to locate the template file that is currently being used to render an element and override it in your own theme. This is an important skill for anyone who wants to make changes to Drupal's default HTML markup.

In this tutorial we'll:

• Override the node.html.twig template in our theme
• Make changes to the markup
• Create a content-type-specific template override like node--CONTENT_TYPE.html.twig

By the end of this tutorial you should be able to modify the HTML markup used to display a node, or any other element of the page generated using a template file.

To add CSS or JavaScript files or libraries to your site, you can attach them as asset libraries in your theme. In this exercise, you'll create 2 asset libraries and attach them globally via your theme's info file. In this tutorial, we'll pull in the CSS and JavaScript from the popular Bootstrap framework so that we can make use of its layout utility classes later on. We'll also add a custom CSS file that contains global styles for our site, like setting the page background color.

If you want to try and complete this on your own first you'll need to:

• Add the Bootstrap CSS and JavaScript files to your theme.
• Define an asset library using a THEMENAME.libraries.yml file in your theme.
• Tell Drupal to attach your asset library so that the CSS and JavaScript files it represents are included in the page.

Once that's done your site won't look all that different. But if you view the page source, or look closely, you should see that the Bootstrap files are included along with any CSS rules you placed into your custom style sheet.

Note: Since this course is focused on teaching the Drupal aspects of theme development, and not on writing CSS, we're using the Bootstrap CSS. Feel free to use the framework or library of your choice if you don't want to use Bootstrap.

You should try to complete the exercise steps on your own and use the video to help guide you if you get stuck.

At the end of this exercise, you'll find a video walk-through of the solution.

In order to change Drupal's default markup you need to override template files. The page template controls the overall layout of your theme, including the placement of regions. You should practice the exercise following the written instructions below. Use the video walk-through to help if you get stuck.

In this exercise, we'll:

• Override the currently used page.html.twig template file.
• Modify the content of the file to include the regions defined in the theme's .info.yml file.
• Wrap the regions in the page template file with HTML markup using CSS classes from Bootstrap to achieve the example layout.

By the end of this tutorial, you'll gain practice creating a custom layout in a page template file.

Some, but not all, themes come with administrator-configurable settings that you can change through the UI. These might allow you to upload your own logo, choose between a couple of different pre-defined layouts, or turn features of a theme on or off. In this tutorial we’ll look at where you can find these theme settings if they exist, and how to go about changing them.

Customizing the available regions in your theme is one of the first things you'll do when creating your own themes. Doing so gives you complete control over where content is displayed on the page, and the markup involved. Adding regions to a theme is a two-step process that involves editing your theme's THEMENAME.info.yml file and updating your page.html.twig file.

In this tutorial we'll:

• Declare one or more new regions in our themes THEMENAME.info.yml file.
• Output the content of those regions in our theme via the page.html.twig file.

By the end of this tutorial you should be able to add or edit the regions a theme provides. Also, you'll ensure that blocks placed into regions are displayed by outputting the regions in the page template.

Drupal has a few handy settings you can tweak to make developing themes a little more intuitive and a lot more awesome. In this tutorial, we'll practice manually setting up our environment for theme development by:

• Disabling some caches
• Turning off CSS and JS aggregation
• Turning on the Twig debug service

By the end of this tutorial, you'll have practiced setting up your environment for theme development.

Themes and modules can alter the list of theme hook suggestions in order to add new ones, remove existing ones, or reorder the list. This powerful feature allows for the definition of custom logic in your application that can tell Drupal to use different templates based on your own unique needs. You might for example; use a different page template for authenticated users, or a custom block template for someone's birthday.

In this tutorial we'll cover:

• Adding new theme hook suggestions from a theme using hook_theme_suggestions_HOOK_alter()
• Altering the list of theme hook suggestions
• Removing theme hook suggestions
• Reordering the list of theme hook suggestions