Media Source plugins in Drupal have a powerful feature, called field mapping, that allows an administrator to configure a Media entity type to automatically populate the value of custom fields based on metadata retrieved from the source content. For example, you can add a creator field to the Remote Video Media type, which can use YouTube as a source. When a content author adds a new Remote Video entity they can provide a URL for the YouTube video. Then the source plugin can extract the creator's name from the YouTube API and use that data to populate a custom field. This saves the content author from having to do that work themselves.
In this tutorial we'll learn:
- How to discover what source metadata is available
- How to configure a Drupal Media type to automatically populate custom fields
By the end of this tutorial you should be able to add a custom field to a Media type on your Drupal site and automatically populate it with data retrieved from the source content.
One of the most powerful features of Drupal's Media Library is that it enables content authors to re-use media entities. Have a favorite image that you like to use with all blog posts about a specific topic? Or a default icon you want to use for a tutorial unless an alternative is provided? The Media Library can accommodate this without requiring you to keep a copy of the image locally and then attach it to every node where it's needed.
This can lead to a potential issue when an editor deletes an image, thinking they've also deleted all the content that used it. If they missed a post referencing the now deleted image, what happens when there is no image to show?
The contributed Entity Usage module provides a mechanism for tracking relationships between entities. This is essential functionality when working with a library of reusable media entities because it helps ensure that media entities attached to content are not deleted.
In this tutorial we'll:
- Discuss the use case for the Entity Usage module
- Learn how to configure Entity Usage to keep track of relationships between media entities and nodes that reference them
- Prevent media items from being deleted if they are in use somewhere on the site
By the end of this tutorial you should be able to explain what the Entity Usage module does, and how to use it to solve common problems related to deleting items from a large Media library.
A commonly asked question is, "How do you add images to the body of a content item in Drupal?" You can allow users to embed images, videos, or any other media into a field configured with a WYSIWYG editor, such as CKEditor. In this tutorial, we’ll show you how to enable Drupal’s Insert Media button for CKEditor, and configure the corresponding text format so that it can render embedded Media entities.
Content authors can then use the Media Library to select images (or other media) to embed into the page.
In this tutorial we'll:
- Learn how to enable the Insert Media button for CKEditor
- Demonstrate how to insert media into the body of a content item (or any other field configured to use CKEditor)
By the end of this tutorial you should know how to configure Drupal to allow content authors to embed images in content items.
Drupal's media management tools, the Media and Media Library modules, provide content authors with drag-and-drop media and asset handling, full WYSIWYG editor integration, and a library of reusable media assets. There's minimal configuration required to get started, but full control via Drupal's standard Entity and Field systems for those who need it.
In this tutorial we'll:
- Provide an introduction to the media system in Drupal and its use-cases
- Explain the Drupal core features that the Media system is built on
- Link to other tutorials that will go into much more depth on these topics
By the end of this tutorial you should know what role the Media and Media Library core modules fill and know whether or not you'll want to make use of them on your project.
Media entities are standard Drupal fieldable content entities. For the most part, they function, and are managed, in the same way as Nodes. So if you've previously created content in Drupal, much of working with Media entities should be familiar -- with some notable exceptions related to the connections between Media types and the media resources they represent.
In this tutorial we'll:
- Get an overview of Media entities, Media types, and Media fields in Drupal
- Point to other tutorials that go into more depth on individual topics
- Learn some basic terminology and concepts related to the Media system in Drupal
By the end of this tutorial you'll have an overview of the pieces that make up the Media system in Drupal core.
Core Themes: Bartik
FreeBartik is a core theme in Drupal. As a default theme for Drupal, it serves as an instructive example of a well-developed responsive theme. In this tutorial, we'll tour and explore Bartik, identify its primary features, and explain the use case for the Bartik theme and what you can learn from it.
Core Themes: Stark
FreeStark 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.
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.
In Drupal's Appearance UI, all themes get a theme settings form. As a theme developer, you can customize the theme settings form, enabling site administrators to have more control over the appearance of the theme.
In this tutorial, we'll show you how to add admin-configurable settings to your theme. In the process of doing this, we'll use a variety of theme and module development skills and assume you have some familiarity with using Drupal's Form API, Configuration API, and theme system (see Prerequisites).
By the end of this tutorial, you will be able to provide custom theme settings that an administrator can use to modify the appearance of the theme.
New asset libraries can be defined by either modules or themes. In order to define a new asset library you need to create the requisite CSS and JavaScript files, and a new THEMENAME.libraries.yml, or MODULENAME.libraries.yml file that aggregates them together and provides metadata about the library itself and any dependencies.
In this tutorial we’ll:
- Look at the structure of a *.libraries.yml file and demonstrate how to combine a couple of CSS and JS files together into an asset library that can be used in a theme or a module
- Look at how one asset library can declare that it is dependent on another in order to ensure the assets from the dependency are loaded as well
By the end of this tutorial you should know how to define a new asset library in either a module or a theme.
Info files, aka THEMENAME.info.yml files, provide Drupal with metadata about your theme, the features it supports, and the regions that it defines. All themes are required to have a THEMENAME.info.yml file, and creating one is generally the first step you'll take when creating a new theme.
In this tutorial we'll:
- Create a new .info.yml file and define a new theme
- Review the required key/value pairs of an .info.yml file
- Enable our new theme in the Drupal UI
By the end of this tutorial you'll be able start a new theme by creating the required *.info.yml file and better understand its contents.
If you want to make changes to the HTML markup of any element on the page you need to first figure out the theme hook or base name of the template file used to generate it. This information is required to override the template in your custom theme.
There are other situations in which knowing the theme hook name of a template file is useful. Including determining which preprocess function affects a template, and which template theme hook suggestions can be used.
In this tutorial we'll learn:
- How to figure out the theme hook name for any template
By the end of this tutorial you should be able to use the output from Twig's debugging mode to determine the theme hook name of any template file.
When determining which template file to use to theme an element, Drupal uses the list of theme hook suggestions to look for the best match. This allows for fine-grained control over how things appear based on dynamic state and contextual information in your application. The list of theme hook suggestions varies for each base template, so we need a way to figure out our options.
In this tutorial we'll look at:
- How to determine the list of valid theme hook suggestions for any template file
- How theme hook suggestions are added by modules and themes
By the end of this tutorial you should be able to explain how theme hook suggestions are added, and determine the valid suggestions for any template file.
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.
Anyone writing JavaScript for Drupal should use the Drupal.behaviors
API when writing their custom JavaScript functionality. Doing so ensures that your JavaScript is executed at the appropriate times during the life cycle of a page, such as when the page loads, or after new DOM elements have been added via an AJAX request.
In this tutorial we'll look at:
- The problem that
Drupal.behaviors
solves - How to use
Drupal.behaviors
when writing your JavaScript code
By the end of this tutorial you should be able to explain what the Drupal.behaviors
API is, and be able to use it in your own JavaScript.
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
Knowing how to inspect the variables available within a template file enables you to discover all of the dynamic content in a Twig file, not just that which is already being used.
In this tutorial, we'll learn how to use {{ dump() }}
, kint()
, vardumper()
, and XDebug to inspect variables in a template file.
Before visitors to your site will see the pages displayed using a theme the theme needs to be installed and set as the default. This is true whether it's a custom theme you wrote yourself, or a contributed theme you downloaded from Drupal.org. Installing themes can be done either via the user interface, or using Drush. Once a theme is installed, users of your site will see all public facing page rendered using that theme. Themes that are no longer being used can safely be uninstalled.
In this tutorial we'll:
- Demonstrate how to install a theme and make it the default using both the UI and Drush.
- Learn to differentiate between installed themes, default themes, and uninstalled themes.
- Configure our site to use an administration theme for the administrative pages.
By the end of this tutorial you should be able to install a theme and make it the one visitors to your site see by default.
JavaScript is used and loaded in special ways within a Drupal site. JavaScript is loaded via asset libraries and Drupal core provides a bunch of different JavaScript libraries that you can load and use in your module or theme. This tutorial provides a brief orientation to some of the JavaScript included in core.
In this tutorial we'll:
- Preview the JavaScript ecosystem in Drupal
- Find pointers to tutorials where you can learn more about adding JavaScript to a theme or module
- Learn about examples of JavaScript in Drupal core that are useful to review for learning purposes
By the end of this tutorial you should have a good overview of how JavaScript is used throughout Drupal core.
Many of the variables that you have access to inside of a Twig template file are arrays. For example a list of values for a multi-value field, or a set of error messages generated when validating a form submission. In order to work with arrays in Twig you'll need to understand how for
loops work. This is essential information for anyone creating Drupal themes.
In this tutorial we'll cover:
- Using the
for
tag to iterate over an array - Using the
loop
variable inside of afor
loop for additional context