WordPress Composer: How to Use Composer for Modern WordPress Development

Developing WordPress sites has grown increasingly complex since its release in 2003. This is a testament to the value it delivers. But a simple FTP upload is no longer the cutting edge of WordPress development. Modern WordPress development tools have evolved.

One tool in particular, Composer, has become the go-to dependency manager for Hypertext Preprocessor (PHP). Developers use Composer with WordPress because it transforms traditional WordPress development into a more modern, maintainable, and scalable process.

This article is a clear, step-by-step guide on how to effectively use Composer with WordPress for dependency management, detailing its benefits and offering best practices for professional development teams.

Understanding Composer: Beyond Just WordPress

At its core, Composer is a PHP dependency manager, helping developers manage external libraries and packages that their projects depend on. It helps avoid dependency chaos by ensuring all required code libraries are present and compatible.

Composer functionality involves reading a composer.json file, downloading dependencies into the vendor/ directory, and generating an autoloader that dynamically loads PHP templates (classes) to reduce the need for manual loading of PHP files.

Composer is a standard tool that delivers great utility across the broader PHP ecosystem.

Why Use Composer with WordPress?

Developers can gain a number of benefits from using Composer with WordPress.

• Centralized Dependency Management: WordPress core, themes, and plugins can be managed as Composer dependencies. Developers can say goodbye to manually downloading zips.
• Version Control and Consistency: WordPress version control allows you to lock specific versions of components (composer.lock). This ensures all team members use the exact same versions.
• Automated Deployment with Continuous integration/Continuous Delivery (CI/CD): Developers can build entire projects from scratch with a single composer install command. This is the perfect setup for automated deployment pipelines with CI/CD WordPress.
• Cleaner Project Structure (for example, Bedrock): Composer facilitates a more organized code base (for example, web/wp for core, web/app for content). This keeps your core WordPress separate from your custom code.
• Easier Updates: Composer commands make it easy to update WordPress core, themes, and plugins.
• Environment-Specific Configuration: Composer is a better option for handling development, staging, and production configurations.

Key Concepts for Composer with WordPress

• composer.json: This is the main configuration file for your project’s dependencies.
• composer.lock: This command records the exact versions of all installed dependencies for reproducibility.
• vendor/ directory: This is where Composer downloads all your project’s dependencies.
• WPackagist: This is a Composer repository for WordPress plugins and themes.
• Bedrock: This is a popular Composer-based WordPress boilerplate that implements many best practices.

Step-by-Step: Setting Up a Composer Managed WordPress Project

Ready to set up Composer WordPress? Here are the basic steps to get you started.

• Install Composer: Ensure that Composer is installed globally across your system.
• Initialize Your Project: Create a new project directory. Then run composer init or start with a boilerplate like Bedrock.
• Define WordPress Core: Add johnp/wordpress-core-installer and wordpress/wordpress to your composer.json. Be sure to specify your desired WordPress core version.
• Configure Web Root and Autoloading: Adjust composer.json to point to the correct web root (for example web/). Ensure that Composer’s autoloader is included in wp-config.php.
• Install Dependencies: Run composer install. This will download WordPress core, the installer, and create your vendor/ directory.
• Configure wp-config.php (Customized): Adjust paths to vendor/autoload.php and wp-content/. Use environment variables (for example dotenv for Bedrock) for sensitive data.
• Database Setup: Create your database and run the standard WordPress installation process via browser/WP-CLI.

Managing Themes and Plugins with Composer

Composer gives you a streamlined way to handle dependencies and updates, especially WordPress plugins and themes. This extends out to a variety of WordPress theme and plugin scenarios.

• Free Plugins and Themes via WPackagist: Add wpackagist-plugin-slug or wpackagist-theme/theme-slug to composer.json. Then run composer update to install and update.
• Premium/Private Plugins and Themes: This requires a custom Composer repository (for example Satis or Toran Proxy) for a plugin like Private Packagist. Alternatively, these can be managed manually or via a separate Git submodule, though this is a less ideal approach.
• Custom Themes and Plugins: Develop them directly within your web/app/themes or web/app/plugins directories. You can then version control them separately or as part of the main project repo.

Best Practices and Advanced Tips

Getting comfortable working with WordPress Composer can take some time. These Composer best practices can help you accommodate more quickly to this dependency management tool.

• Version control composer.json and composer.lock. This action is essential for reproducibility.
• Exclude vendor/ from Git. Use .gitignore to help reduce repository bloat.
• Use environment variables. These dynamic values are crucial for separating configuration from code, especially for sensitive data like database credentials.
• Embrace WP-CLI. Use it in conjunction with Composer for automated tasks.
• Implement CI/CD. Automate your testing and deployment steps.
• Keep dependencies updated. Regularly run composer update.

Composer Positions WordPress for the Future

Developers use Composer with WordPress because it transforms and modernizes traditional WordPress development workflows.

In using Composer, developers gain centralized dependency management, version control and consistency, automated deployment, cleaner project structure, easier updates, and environment-specific configurations.

Adopting Composer is a crucial step toward building more maintainable, scalable, and professional WordPress applications, especially for teams. I encourage you to integrate Composer into your next WordPress project to experience its powerful benefits firsthand.

Pressable Supports Composer for WordPress Development

Pressable makes it easy to use Composer with your WordPress site. We provide a hosting foundation backed by 100% uptime infrastructure and global CDN edge caching. Your site’s page loads are optimized to deliver an efficient and consistent experience to your visitors. We give you the technical confidence you need to focus your attention on managing the other parts of your site, including your WordPress Composer workflows.

Pressable—part of the Automattic family that also includes WordPress.com, WordPress VIP, and WooCommerce—is staffed by experts with the skills and knowledge to effectively manage your WordPress site. If you’re thinking about switching to managed WordPress hosting, schedule a demo to see how Pressable can support your continued optimization and growth.

Varsha Adusumilli

A dedicated WordPress user since 2007, Varsha has witnessed the platform’s growth and transformations firsthand. With a Masters’ in Computer Science and experience as a web designer/developer, Varsha possesses a strong foundation in various web development technologies. Her entrepreneurial spirit and freelance background further honed her ability to think creatively and deliver results. This deep understanding, coupled with her technical skills and customer-centric approach, makes her a great part of the Pressable Team. Her genuine desire to help others and her knack for finding solutions make her a customer success rockstar.