When Ruby on Rails was introduced, web developers flocked to it, quickly building applications that have become utterly indispensable to their organisations. But those early Rails applications have often proven extremely difficult to maintain, evolve, and scale. Now, in Component-Based Rails Applications, Stephan Hagemann introduces a practical, start-to-finish methodology for modernising and restructuring existing Rails applications with modern components. One step at a time, Hagemann demonstrates how to revamp Rails applications to exhibit visible, provably independent, and explicitly connected parts--thereby simplifying them, and making them far easier to manage, change, and test.
The first and only guide to componentising Rails, this book offers hands-on, step-by-step coverage of

• Creating a full-fledged component-based Rails application from the ground up
• Refactoring an existing Rails application to extract components
• Using gems and engines to implement components in Ruby and Rails code bases
• Applying modern patterns such as DCI and hexagonal architecture
• Overcoming the unique challenges that arise during componentisation of Rails applications

Throughout, Hagemann introduces concepts and techniques that developers can use to improve applications of many kinds, even if they weren't built with Rails or Ruby.