Solr compartmentalizes itself into cores (or collections if you're using SolrCloud). Each Solr core has its own directory, configuration, and set of search data. While a core can be thought of as an “index”, it is much more.

In this tutorial, we'll:

• Identify the difference between a Solr core and an index.
• List the various ways a core can be created.
• Explain why Search API needs a custom core configuration.

By the end of this tutorial you should be able to explain what Solr cores are, and how to create a Solr core (or collection) that is compatible with Drupal's Search API module.

Reference field types, such as taxonomy term fields, paragraph fields, or plain entity reference fields, refer to a completely separate entity within the site. This makes search configuration complicated as the typical scope of a search crawl is on a per-node (really a per-entity) basis. Fortunately there are known strategies to index these fields with ease.

In this tutorial, we'll:

• Describe why reference types pose a particular challenge to indexing
• Discuss the importance of display modes in indexing
• Highlight how the Rendered HTML Output field can be used to index paragraphs

By the end of this tutorial you should be able to add reference fields to your Search API Index and allow users to search their contents in the correct context.

Once we have the docker-compose.yml file created, we can use it to work with a set of containers. Instead of the docker command, Docker Compose has its own command to work with multiple containers at once: docker-compose.

In this tutorial, we'll:

• Cover the basic usage of the Compose command
• Describe how to start, stop, and list running container sets

In this lesson, you’ll learn some tips for ensuring a successful launch and the importance of celebrating the accomplishments of the team.

The term web services has been around for quite a while. Given that web services is such a broad topic, let's define what web services are and how we are going to refer to them throughout this series so we are all on the same page.

This tutorial is an introduction to web services that will help you:

• Learn what a web service is.
• Understand that this series focuses on HTTP web services, and mostly on REST principles.
• Get some examples of APIs in the wild and what type of consumers they have.

By the end of this tutorial, you'll be able to define what web services are, and how we'll use the term in the context of these tutorials.

Whether you're updating from Drupal 6 or Drupal 7, or importing data from some other source, you need to know about the migrate system in the latest version of Drupal. This tutorial provides an overview and links to additional tutorials where you can learn more about how all the individual parts work.

By the end of this tutorial you should have a better understanding of what the migration system is capable of and know where to find more information about how to use it.

Each form is defined by a controller, a class that implements the \Drupal\Core\Form\FormInterface. Form controllers declare the unique ID of the form, the $form array that describes the content of the form, how to validate the form, and what to do with the data collected.

In this tutorial we'll:

• Define a new form controller class
• Implement the required methods to describe a form
• Add a route that can be used to access our form

By the end of this tutorial you should be able to define a form that adheres to the FormInterface requirements and know where to find more information about how to further customize your form controller.

Drupal's Form API is a set of interfaces, utility classes, and conventions that when combined together allow module developers to create forms that collect, validate, and process user-submitted data. The Form API is closely related to the Render API. It uses Render Arrays to define forms, and adds an additional level of workflow and processing to enhance the Render API with some features specific to handling forms.

Given that forms are one of the primary means of interacting with a Drupal site via the UI, understanding how the Form API works is a critical part of learning to develop modules for Drupal. While you may not need to know all the nitty-gritty details, every Drupal module developer is likely to encounter aspects of the Form API at some point. Understanding the basics should be considered required knowledge.

Theme developers are also likely to encounter some aspects of the Form API, as forms are inherently part of the look and feel of a site. Knowing how to make changes to the UX of a form is an important skill.

In this tutorial we'll:

• Describe what forms are and how they are used in Drupal
• Explain the relationship between Form API and the Render API
• List some of the benefits of using the Form API over generic HTML forms

By the end of this tutorial you should have a solid understanding of the role of the Form API in Drupal.

Some Drush commands return a lot of information -- lists of modules, generators, and status reports, for example. It might be hard to find a property you need in the small command window output. Luckily, the output of Drush commands can be piped to other commands, used as a source for imports, settings for CI, and other DevOps tasks.

In order to accommodate all these different use cases, Drush comes with a formatting system that allows you to format and filter output to meet your needs. This system allows to you specify what fields you want returned when the output contains more than one field. It also allows Drush command output to be formatted as JSON, XML, raw PHP, a table, and more.

In this tutorial we'll:

• Learn how to specify the output format -- and what formats are available
• Limit the fields that are returned in a report
• Learn to filter the output to only the data we're interested in

By the end of this tutorial you'll know how to format a Drush command's output to fit your needs.

Entities are the building blocks that make up just about everything on a Drupal site. Regardless of whether entities provide configuration information or content, they are absolutely crucial to Drupal's data model.

In this tutorial we'll:

• Look at the overall class hierarchy between the various entity types to see how they're related.
• Examine differences between configuration and content entities in the code that defines them.
• Look at some of the core code required to create an entity type.

By the end of this lesson you should be able to use an example to create a custom entity type in code.

Often it's useful for a container image to provide several variants of itself under the same name on Docker Hub. Docker uses tags to identify these variants. You can configure your own tags as part of your automatic build on Docker Hub.

In this tutorial, we'll:

• Outline the uses for tags
• Discuss the best practices for tag names
• Learn how to add tags to your automatic build on Docker Hub

This video goes through the process of creating a configuration form in order to save settings to the variables table in the database, and how to integrate those variables into your module.

Correction

The $item array in the function demo_menu() should be named $items, to match the return $items; line. (Either that or return $items; should be fixed to return $item;.) Just make sure the array you are building matches the name of the variable you are returning.

Additional resources

Form validation in Drupal

"There's a module for that."

You've probably heard this before. Many times you can find a module that provides the functionality you need — or at least pretty close to what you need. Drupal's contributed module projects number in the thousands, but what if there isn't a module for your use case? You just might need to build a module for that.

In this series, you will learn about the tools and resources available to Drupal developers, including where to find documentation and what APIs are available to you, both on drupal.org and api.drupal.org. We'll take a look at the Devel module and learn how to use it to inspect the variables, objects, arrays and other things at work under the hood of Drupal 7.

You'll build several different modules that explore and interact with Drupal's various systems and API, including:

• Form API
• Menu system
• Hooks
• Render API
• Theme system
• Database API

Over the course of this series you'll be able to:

• Describe the anatomy of a module
• Implement common hooks
• Write more secure code
• Interact with Drupal's menu system
• Create and alter forms
• Peform CRUD operations on a database

This series starts with the basics and moves you step-by-step to more advanced concepts. Even if you are quite comfortable with PHP but are struggling to understand how to appropriately interact with Drupal 7's API, the lessons in this series can help you develop "The Drupal Way."

Additional resources

Devel module at Drupal.org

A powerful facet combination is to create a search Facet on a taxonomy field. This brings several advantages to how your search can be configured and displayed.

In this tutorial, we'll:

• Describe the additional complexities for using a reference field for a facet
• Show how to use taxonomy weights to control facet option order

By the end of this tutorial you should be able to add a facet that allows users to filter search result based on taxonomy terms.