Drupal 10 Masterclass E-Book

Adam Bergstein

• Herausgeber: Packt Publishing
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 345

Veröffentlichungsjahr: 2023

Beschreibung

Learning Drupal can be challenging because of its robust, extensible, and powerful capability for digital experiences, making it difficult for beginners to grasp and use it for application development. If you’re looking to break into Drupal with hands-on knowledge, this Drupal 10 Masterclass is for you.
With this book, you’ll gain a thorough knowledge of Drupal by understanding its core concepts, including its technical architecture, frontend, backend, framework, and latest features. Equipped with foundational knowledge, you’ll bootstrap and install your first project with expert guidance on maintaining Drupal applications. Progressively, you’ll build applications using Drupal’s core features such as content structures, multilingual support, users, roles, Views, search, and digital assets. You’ll discover techniques for developing modules and themes and harness Drupal’s robust content management through layout builder, blocks, and content workflows. The book familiarizes you with prominent tools such as Git, Drush, and Composer for code deployments and DevOps practices for Drupal application management. You’ll also explore advanced use cases for content migration and multisite implementation, extending your application’s capabilities.
By the end of this book, you’ll not only have learned how to build a successful Drupal application but may also find yourself contributing to the Drupal community.

Leseprobe

Drupal 10 Masterclass

Build responsive Drupal applications to deliver custom and extensible digital experiences to users

Adam Bergstein

Drupal 10 Masterclass

Copyright © 2023 Packt Publishing

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First published: December 2023

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Published by Packt Publishing Ltd.

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ISBN 978-1-83763-310-4

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To my girls, Leah and Nora, for their learning, to help their generation, and to show you can chase your dreams.

– Adam Bergstein

Contributors

About the author

Adam Bergstein is a product engineering leader and an architect. He has been a long-time Drupal community member, a routine speaker at Drupal community events around the globe, and provided keynotes for several events. He has maintained and contributed to many Drupal projects, including Password Policy, Taxonomy Menu, and more. Adam is the lead of Simplytest, a free service, and a project that offers testing sandboxes to Drupal community members. He has also worked for both–agencies building Drupal applications and Drupal service providers building Drupal-related products. He has led the Drupal Community Governance Task Force and is serving a term as a community board member of the Drupal Association.

Mike Herchel, author of Chapter 19, is the primary developer behind Drupal’s default theme (called Olivero), as well as a maintainer of Drupal core’s CSS subsystem. He’s on a crusade to improve Drupal’s front-end developer experience for those new to the Drupal ecosystem. If you have feedback on this, or thoughts on what’s hard to accomplish, please reach out to him at [email protected]. The work on this chapter was traded for beer, and in fact, if you find Mike at a local DrupalCamp, you can typically get him to do core development in exchange for beer.

About the reviewer

Rachel Lawson has been working in open source communities, primarily Drupal, for the last 17 years. Rachel has held diverse roles across education, defense, and pharmaceuticals, learning many of her community skills as a mentor, core mentoring coordinator of the Drupal open source project, and community liaison for the Drupal Association. She has most recently had the opportunity to take many of the good practices in open source into international development with the Digital Impact Alliance at the United Nations Foundation.When not working, Rachel can usually be found planning or enjoying her next overland adventure on her motorbike – 26 countries in 4 continents so far, where’s next?

Table of Contents

Preface

Part 1: Foundational Concepts

1

What is Drupal?

What is a CMS?

Frameworks and extensibility

Basic Drupal concepts

Drupal’s administrative backend

Drupal’s frontend presentation layer

Popular Drupal case studies

Summary

2

Drupal Core, Modules, and Themes

Drupal core

What is core?

Core features

Core systems

Core development

Overview of Drupal projects

Drupal modules

What is a module?

Popular community modules

Drupal themes

What is a theme?

Core themes

Contribution

Summary

3

Infrastructure and Overview of Technical Architecture

Hosting Drupal and platform requirements

Drupal architecture

Infrastructure technical stack

Application architecture

Backend architecture

Frontend architecture

Drupal management and operations

Maintenance

Operations

Summary

4

Drupal Community

Understanding the open-source community

Drupal.org basics

Core on Drupal.org

Core contribution

Projects on Drupal.org

Contribution impact

Other community resources and tools

Summary

5

What’s New in Drupal 10

Release methodology

Platform requirements

Upgrade considerations

Major releases

New to Drupal 10

Symfony 6.2

CKEditor 5

Olivero

Claro

Starter kit themes

Built in Drupal 10

Automatic updates

Recipes

Decoupled menus

Project browser

Summary

Part 2: Setting up - Installing and Maintaining

6

Bootstrapping, Installing, and Configuring a New Drupal Project

Establishing a new codebase

What is Composer?

Composer projects

Common commands

Installing Drupal

Installation preparation

UI-based installation

Performing an installation with Drush

Post-installation

Out-of-the-box Drupal Building

Developer Classification

Site Building Concept

Requirements Gathering

Beyond core features

Basic configuration

Post-installation configuration

Common configuration changes

Help, logs, and reporting

Help

Logs and Reporting

Summary

7

Maintaining Drupal

Types of maintenance

Code-related maintenance

Infrastructure platform maintenance

Code maintenance process

Reviewing code management and deployment concepts

Typical code maintenance process

Best practices

Backups

Environment differences

Managed platforms

SaaS services

Update frequency

Product life cycles

System monitoring and tools

Edge systems

Summary

Part 3: Building - Features and Configuration

8

Content Structures and Multilingual

Importance of structured content

Relational database best practices

Structured content in Drupal

Entities, types, and bundles

Fields and field types

Base entities

Content entities

Entity example for Node

Example models

Configuration entities

Under the hood

Site building

Applying to other features

Multilingual features

Modules

Summary

9

Users, Roles, and Permissions

Users

User entity

Features

User management

Roles

Role entity

Default roles

Configuring roles

Permissions

Access control

Types of permissions

Managing permissions

Permission definition

Summary

10

Drupal Views and Display Modes

Defining Views

Overview

Views features

Customizing Views

Defining display modes

Overview

Popular use cases

Using Views and display modes

Creating a teaser display mode for blogs

Creating a View for a blog listing – option 1 with teaser display mode

Creating a View for a blog listing – option 2 with fields

Explaining the Views editing interface

Creating an RSS feed display

Summary

11

Files, Images, and Media

Assets in Drupal

Use cases

Files

Subsystem

Modules and configuration

Images

Modules and configuration

Media

Modules and configuration

Use cases

Creating research papers

Icons for sports

Tutorials found in YouTube videos

Summary

12

Search

About the feature

Implementation

Frontend experience

Backend

Configuring search

Search pages

Extending Search

Facets

Third-party indexes

Autocomplete

Use cases

Querying for two different movie titles simultaneously

Filter by sport

Restricting a specific content type from search

Summary

13

Contact Forms

Contact forms in Drupal

Basic information

Form management

Form submissions

Configuring contact forms

User profile configuration

Permissions

Extending contact forms

Viewing and managing form submissions

Beyond just a page

More robust email notifications

Spam prevention

More advanced forms

Summary

Part 4: Using - Content Management

14

Basic Content Authoring Experience

Authoring content

Nodes

Menus and taxonomies

Authoring digital assets

Summary

15

Visual Content Management

Blocks and custom block types

Managing blocks

Custom block types

Layout Builder

Configuring a default layout

Node-specific layouts

Setting up Layout Builder

Contributed projects

Paragraphs

Gutenberg

Summary

16

Content Workflows

Configuring workflows

Managing states

Managing transitions

Managing workflows

Managing permissions

Using workflows

Use case

Summary

Part 5: Advanced Topics

17

Git, Drush, Composer, and DevOps

Technical requirements

Git basics

Setup

Common commands

Drush basics

Setup

Common commands

Composer basics

Setup

Common commands

DevOps practices

A developer pushes a new commit to a development branch

Developer reviews and merges code into the main branch

Tag-based deployments for release candidates

Addressing production deployments

Summary

18

Module Development

Concepts

Early Drupal concepts

Modern Drupal concepts

Common patterns

PHP patterns

Symfony capabilities

Drupal patterns

Module definitions

Configuration

PHP code

Templates

Summary

19

Theme Development

Technical requirements

Setting up for theme development

Disabling CSS and JS aggregation

Setting up theme debugging and disabling caches

Turning on verbose error messages

Creating a new theme using the theme generator tool

Creating a new theme from scratch

Creating your dexter.info.yml

Creating your dexter.libraries.yml file

Creating your CSS directory and files

Creating your templates directory

Creating your JS directory

Creating a new theme from a base theme (subtheming)

Popular base themes

Working with Libraries API (and where to put CSS/JS)

Loading the library globally through your theme’s *.info.yml file

Attaching the library through a Twig template

Loading the library programmatically through preprocess

Overriding another module’s or theme’s libraries

Managing dependencies

Notes on CSS grouping

Setting weights and other options

Working with templates

How to find and create templates

Twig basics

Twig filters

Twig functions

Working with the attributes object

Preprocessing data and PHP

Working with CSS

Working with JS

Drupal behaviors

Passing data from PHP into JS

Single Directory Components

Drupal accessibility tips

The visually hidden CSS class

Drupal announce JS API

Using buttons as menu items

Contributed modules that help with theming

Summary

20

Delivering Drupal Content through APIs

Web services primer

Web service APIs in Drupal

Concepts

Modules and configuration

Using web services

Basic JSON:API examples

Basic REST API examples

REST clients

Summary

21

Migrating Content into Drupal

Migration concepts

The Migrate system

Extract

Transform

Load

Custom events

Operating migrations

Contributed modules

Use cases

Summary

22

Multisite Management

The multisite feature

Benefits

Drawbacks

Automating deployments across many sites

Summary

Appendix A - Drupal Terminology

Index

Other Books You May Enjoy

Part 1:Foundational Concepts

This part covers all of the basics for Drupal. You will get an overview on what Drupal does at a high level followed by understanding the differences between core, modules, and themes. A review of the supporting infrastructure and Drupal's primary architectural components are covered. The open source community and their practices are reviewed. And, the part finishes by reviewing the new features of Drupal 10.

This part has the following chapters:

Chapter 1, What is Drupal?Chapter 2, Drupal Core, Modules, and ThemesChapter 3, Infrastructure and Overview of Technical ArchitectureChapter 4, Drupal CommunityChapter 5, What’s New in Drupal 10

1

What is Drupal?

Drupal is a popular content management system (CMS) for building websites, web applications, and digital experiences. With such flexibility, it can be difficult to define exactly what Drupal is. This chapter explores that question in depth to clarify its identity, purpose, and objective.

The goal of this chapter is to provide a solid foundation that we will build upon in the more practical, hands-on chapters found later in this book. Learning basic concepts and understanding the community are essential for anyone who wants to work with Drupal.

In this chapter, we will explore the following topics:

What is a CMS?Framework and extensibilityBasic conceptsPopular case studies

What is a CMS?

A CMS, in its simplest form, is a tool to create, update, maintain, and present content. This was historically for websites, but now, they’re commonly used for digital experiences given the rise of omnichannel content delivery. The foundations of the web started with servers delivering static HTML files over the internet. Tools that abstracted technical complexities in building HTML, such as Macromedia Dreamweaver, allowed non-technical audiences to author websites without knowing how to code. HTML files would be modified on someone’s personal computer and subsequently pushed up to a web server through protocols such as FTP or SFTP. A CMS abstracts both the coding and the file-based operations to enhance the capabilities of a system. Many CMSs also handle content delivery given that managing content has evolved to address more complex use cases with specific access controls, editorial reviews, and more.

The modern CMS has evolved to serve several popular use cases. Many eCommerce websites manage products, pricing, and promotions through a CMS where the system manages shopping carts, users, and payment transactions. Social networks, such as Twitter and Facebook, harness content management capabilities to deliver user-specific, innovative digital experiences.

Enterprise CMS systems must account for much more than just browser-based content delivery, which explains Drupal’s evolution. Omnichannel capabilities often allow a CMS to serve as a central content store while allowing the same content to be served across any channel from a website, app on your phone, a notification stream, and more. A CMS is now viewed as a major enabler for an effective digital strategy spanning simple websites for small businesses to a highly integrated content store for major corporations. Over time, Drupal has added the features and extensibility necessary to be a platform that enterprises adopt.

CMS systems began by managing content published on basic websites. Today, applications such as Drupal have evolved to be able to dynamically deliver content through many channels and manage data across a vast amount of enterprise capabilities. Recognizing this evolution helps explain Drupal’s position in the space of CMS solutions as an enabler not just for simple website use cases, but far more.

Frameworks and extensibility

I once heard Drupal described as analogous to Lego building blocks in that Lego blocks of all shapes and sizes; what can be created is limited only by your imagination. Many people have attempted to define what Drupal is. While a clear definition may help people understand when and how to adopt Drupal, if Drupal is of interest to them, or if Drupal can help them deliver a specific solution effectively, this is not a constructive way to understand what Drupal is.

Drupal is a tool. What is delivered with the tool can vary drastically. That is why the Lego analogy works. With Lego blocks, you can build a house, a car, a Star Wars figure… practically anything. Lego blocks empower a builder to create what they want to create. Often, people want a clear definition of Drupal. Is it a house, a car, or a Star Wars figure? No – it is a tool that helps you create the digital experiences you want to build. While I understand a desire to define what Drupal can be used for, looking at Drupal in this manner can be significantly limiting.

Drupal grew in popularity as a CMS. Drupal empowered site builders by offering a user interface for configuring structured content and serving that structured content as rendered HTML. Imagine a system that can be used to both create and deliver websites. Drupal offers that. Content is stored persistently by authors and then rendered for site visitors dynamically. Drupal is an application developed in PHP that leverages a database storage backend. Older CMSs simply managed static files, whereas Drupal is a functional system that can be programmed to manage content. Page requests do not correspond to static files; instead, they are dynamically processed by Drupal. The system interprets a URL, parameters, and sessions to deliver a unique, generated result back to the browser at the time the request was made. Some requests get content, others serve the user interface to manage content. Drupal handles all of that.

However, Drupal can do much more than basic content management. Out of the box, the core of Drupal delivers many features that allow it to be configured for conventional content management. This includes structured content, WYSIWYG, media/static file management, caching, rendering content displays, API-based content delivery, and more. However, Drupal also comes with a highly extensible framework that allows for it to be customized. Given Drupal is open source, community members have contributed their customizations back to the open-source community as projects that can be downloaded and installed on any Drupal application.

The goal of this book is to show how Drupal, its out-of-the-box features, and contributed projects can be built and configured to deliver amazing digital experiences. Like a large box of Lego blocks, the aim of this book is not to define exactly what can be built but to show you how to use the tool to accomplish a large number of potential outcomes. What you do is only bound by your imagination.

Basic Drupal concepts

Drupal’s core delivers two fundamental parts of the application: a frontend web application and a backend administrative system. Both are delivered through the Drupal application, which can be accessed from a web browser differentiated based on the request. Common backend paths, such as the user login page “user” and administrative console “admin,” help Drupal differentiate requests.

Drupal’s administrative backend

Conceptually, Drupal’s backend performs tasks and retrieves information about the Drupal system. Tasks change based on the access granted to the user. However, common tasks include performing content updates, configuring Drupal system settings, and managing modules. Useful information, such as Drupal’s system status page, access to Drupal logs, and help pages, can also be accessed from Drupal’s backend. It is useful for content editors and those managing the Drupal system.

The following figure demonstrates Drupal’s administrative backend, which can be found at /admin after logging in:

Figure 1.1 – Drupal’s administrative home page

At the top, Drupal has an administrative menu that helps navigate the entirety of Drupal’s administrative backend. This figure demonstrates the initial, primary administrative page that lists links within Drupal’s backend. Each category has a gray background that represents a core feature or subsystem. Under each category are links to pages that perform administrative actions or configure the behavior of that subsystem.

Drupal’s frontend presentation layer

Since the backend configures Drupal and manages content, the frontend is responsible for serving content. Drupal’s render subsystem is used to correlate a page request to the corresponding response, which is dynamically returned by Drupal. While there is far more complexity, a high-level request flow interprets the path, gathers the relevant structured content from Drupal’s backend, maps the content to HTML templates found in the enabled Drupal theme, and returns rendered markup.

The following figure shows Drupal 10’s default home page rendered by the frontend presentation layer:

Figure 1.2 – Drupal’s default home page

While this shows simple, basic placeholder content, it differs drastically from Figure 1.1, given that it is presenting content and not configuring Drupal.

Consider authenticated users while using Drupal’s frontend and backend. Drupal can deliver content, but not just for anonymous visitors who visit a Drupal website. During frontend processing, Drupal can render content specific for the user who’s being authenticated. Such a capability allows you to leverage Drupal features to build dashboards with individualized content, create personalized experiences, and even deliver content moderation workflows that pair with Drupal’s frontend. The most common use case for authenticated users is still accessing and using the administrative backend of Drupal, but a user can be configured without permission to access the backend. Given users have an expanded role in Drupal, a user can log into Drupal with no backend access and get content that’s specific and relevant to them. Imagine building a social network where every user only sees content they subscribe to. Drupal can do that.

Popular Drupal case studies

Drupal case studies start with their fundamental content management features, which build off of structured data. Drupal has been commonly used for blogs, websites, or news. Stanford University offers a web content management program that delivers Drupal and various content management features as a service through their IT department. The State of Georgia offers a similar web platform built with Drupal. Other popular Drupal websites include London.gov.uk, home.cern, unicef.org, the Syfy network, the State of Massachusetts, The Weather Channel, Tesla, Entertainment Weekly, NCAA, the Emmy Awards, and NASA.

Distributions in Drupal often represent popular use cases for Drupal, reducing the time and cost of creating multiple sites that have similar requirements. Websites built with the Open Social distribution (getopensocial.com) help create community-based websites with groups, events, private messaging, and enhanced user profiles. Case studies include Local Gov Drupal (drupal.org/project/localgov), The United Nations, The Salvation Army, and The European Commission. Drupal Commerce is a distribution tailored for eCommerce websites, with a series of optional features for payment gateway integrations, promotions/coupons, analytics, shipping, and fulfillment. Case studies include EuroCentres, Open Sesame, and Artellite.

Drupal has countless published case studies and even more undocumented installations that highlight its wide adoption. These case studies demonstrate Drupal’s ability to be used in different industries and verticals, as well as for different implementations.

Summary

This chapter covered introductory concepts regarding CMSs and highlighted how Drupal built a CMS through its high-level features. First, we introduced Drupal’s framework and extensibility value proposition, which enables both its vibrant community and enterprise-level customizations. Next, we reviewed Drupal.org, which introduced you to how to engage with the community, work with community projects, and the purpose of the Drupal Association. Finally, we looked at some case studies that demonstrate Drupal’s capabilities. The next chapter dives deeper into projects by reviewing core, contributed, and custom projects.

2

Drupal Core, Modules, and Themes

Drupal starts with a powerful, foundational core that all Drupal applications build from. This chapter describes what core is, how it was conceptually created, how to harness it to create a Drupal application, and how an application can be extended beyond just core. Learning how to create Drupal applications starts with enabling and configuring Drupal core features. It is only after leveraging core that the application should be extended through contributed and/or custom projects. This chapter serves as the foundation for configuring applications, understanding high-level architecture, and then solving additional problems through extended projects.

In this chapter, we’re going to cover the following main topics:

Drupal coreOverview of Drupal projectsDrupal modulesDrupal themesContribution

Drupal core

Drupal core is the foundation of every Drupal application. It represents all out-of-the-box Drupal features and contains the framework every Drupal application is built on. It has the most rigorous contribution process while having the largest amount of contribution activity.

While Drupal itself, as an open source project, is free, it should be viewed more through the perspective of “free like a puppy.” Drupal code is freely available, and there is a vast community helping to maintain and support it. However, Drupal applications require ongoing maintenance. Major and minor upgrades need to be performed to update the code. The underlying servers and platform need to be maintained as core evolves its platform dependencies. The community helps promote efforts to more seamlessly and automatically perform code updates, but adopters are still largely responsible for running their own platforms or picking a commercial PaaS offering. This takes ongoing work and investment as it requires a conscious decision from those selecting Drupal as their digital experience framework. But Drupal and the framework that core provides can be extensible and address complex, enterprise digital needs that can deliver value in ways other platforms simply cannot. While it can complicate upgrades with the added complexity of custom code, these capabilities position Drupal as a powerful tool capable of addressing enterprise needs. Even with efforts that simplify the maintenance work required, adopters still need to understand Drupal and the systems required to run it. Small businesses that cannot make this investment may not be in a position to effectively get the same value out of Drupal as an enterprise would. Professionals should advocate for the right tool for the right job.

What is core?

Every house has a foundation. Every car has a frame. And every Drupal application has a core. It is the basis of all Drupal applications.

Drupal core is an out-of-the-box Drupal application. When the core is first downloaded, the application loads Drupal’s core installer. After installation, the application renders Drupal’s content and affords access to Drupal’s core user login feature. Logged-in users can access Drupal’s administrative systems and content management tools. All of this is facilitated by Drupal’s core.

Drupal core is built to be modular. In this definition, there are a series of independent parts that encompass all of Drupal’s core. This modularity is incredibly useful to afford Drupal developers the ability to enable or disable parts independently based on their use case, and many of the parts of Drupal core are extensible through configuration and the framework. The core of Drupal and its modularity serve as an underlying design principle that has allowed Drupal to solve countless problems in the digital space and be able to deliver on a wide array of various use cases.

Drupal’s core also helps drive some governance aspects of Drupal. As an example, Drupal core sets the various system requirements needed for running the Drupal application. Drupal core has explicit open-source licensing that influences all other Drupal communities and projects. Developing core often sets the highest standard for contribution to a Drupal project through processes, tooling, quality standards, and more.

Core features

Drupal core also has a set of common features. The features deliver Drupal’s out-of-the-box value and help to differentiate Drupal from other digital content management applications.

Content management features help deliver on Drupal’s promise as a content management system (CMS). Such examples include the following:

Structured content: Nodes, content types, blocks, fields, field types (dates, phone numbers, links), and taxonomyContent features: WYSIWYG, comments, moderation/workflows, layout builder, API feeds/web services, multilingual, Drupal views, statistics/analytics, forums, books, and blocksDigital assets: Files (PDFs, Word documents), media (images and videos), and responsive image managementMigration: Methods to import and export content within DrupalEngagement: Contact forms and search

Administrative features help provide the content management experience, manage Drupal features, or change Drupal’s settings. These include the following:

Authorization/authentication: User roles and permissionsConfiguration: Changing settings of the Drupal application, and managing the state of the application’s Drupal configurationLogging: Accessing and managing Drupal logsDocumentation: Help pages, inline help, and tours

Important note

It is always important to leverage Drupal core’s out-of-the-box features before performing custom development or installing other projects. Drupal core itself is feature-rich, and it is the most established aspect of Drupal. The core should be leveraged before extending it.

If some of the terminology or concepts are new to you, don’t fear this. These features are covered in depth in future chapters.

Core systems

Drupal core is built on subsystems. Some subsystems can be considered features of Drupal, while others are low-level, fundamental capabilities that a feature can leverage. Some pragmatic examples of features include the “node” system, which is common for structured content, and the “media” system used for file asset management. Low-level subsystems include the module subsystem, which allows Drupal to be modular, and the database subsystem, which allows for persistent Drupal storage (not assets). The combination of these subsystems provides both the framework and the features offered by the core out of the box.

Some examples of these core systems include the following:

UserCronThemeCacheEntityBatchQueueDatabaseInstallerLocaleMailPluginTest

Core development

Drupal is a PHP application that has harnessed modern PHP development practices. Drupal core is built on Symfony components that, in essence, offer low-level capabilities that Drupal adopted. Earlier versions of Drupal had their specific systems built into core that overlapped with widely adopted open-source capabilities offered throughout the PHP ecosystem. Drupal 8 introduced this change, which was a significant architectural shift from a more procedural legacy PHP application into more of an object-oriented (OO), modern PHP approach. Composer, a popular PHP-based command-line tool, is used to manage Drupal’s dependencies to pull projects and versions based on the core’s provided directives. Both the use of Symfony components and Composer represent common practices of modern PHP applications and allow Drupal to more effectively focus effort on its value proposition. It also allows Drupal community members to contribute to and influence the broader PHP ecosystem.

Overview of Drupal projects

Drupal core leverages projects as the construct for its modularity. Projects are built with code and harness Drupal core’s framework to customize Drupal. Community members have contributed their projects on drupal.org. Projects created for the specific needs of a Drupal application are known as custom. Custom projects are intended to add specific business logic that may be unique to an organization, integrate internal enterprise systems, or add specific company branding.

Important note

Before creating custom projects, evaluate the contributed projects on drupal.org. Given the maturity of the Drupal project and the vast number of contributions, it is common to find a contributed project that can help address the desired use case. This all assumes the feature is not provided by the core itself.

Projects are managed by Drupal core for the application. Core can install, enable, and disable projects. Each version of the project is managed so that the core can check for updates. Core also has the concept of update hooks, which allow for new versions of a project to perform specific tasks once new code exists.

Drupal modules

The first type of project is known asa module.

What is a module?

A module is a code that leverages Drupal’s framework for backend customization. This often modifies the Drupal application and is processed within the server. The core itself organizes its features by leveraging modules. This way, each application can control which core modules are installed based on the desired needs of the application.

Modules have compatibility with the core. Every major version of the core modifies its framework. Given the framework changes, modules must provide metadata that defines their compatibility with major core versions. It should not be assumed that every module found on drupal.org is compatible with the version of Drupal on the application. In fact, given that Drupal now has 10 major versions, basic searches for modules can find modules dating back to early versions of Drupal. Popular modules from earlier versions may have even been moved into core in later versions (for example, Views). The Content Construction Kit (CCK) module served as the basis for what later became Drupal’s Entity system.

Popular community modules

Given the number of Drupal applications in the world, community members have created a large number of modules aimed at solving specific problems. It is best to check on drupal.org before investing time in coding something someone else contributed.

Some popular module examples include the following:

Webform: A robust and extensible form-building solutionRedirect: Creates manual and automatic path redirection, especially useful to have old content point to new contentPathauto: Provides automatic path generation forcontent managersGoogle Analytics: Enables integration with Google AnalyticsTaxonomy Menu: Allows for a hierarchical taxonomy to be rendered as a menuAntibot: Spam protection for form submissionsSitewide Alerts: A solution that posts a banner message at the top of every pageMetatag: Delivers more metadata for content toward