Summary

In this chapter, you were introduced to the concept of dependency management and Composer, the primary tool for bringing external dependencies into your projects in PHP. Dependency management is important to keep your own application code separate from third-party libraries that need to be kept up to date and compatible with one another.

We covered Packagist, Composer's companion site that catalogs packages available for inclusion in projects. You can identify reputable packages by noting the rating, the number of downloads, and other such criteria. The site links to the source code of each of its listings, so you can review the code yourself if you need a better understanding of its inner workings or if you want to confirm the quality of the code.

We provided an overview of setting up your project to use Composer and how to use the essential features you will need to integrate with other libraries. Libraries are required in the command line or by editing the composer...