Learn Enough Ruby to Be Dangerous: Write Programs, Publish Gems, and Develop Sinatra Web Apps with Ruby

Chapter 10

A Live Web Application

In this final chapter, we reach the culmination of this Ruby tutorial: a dynamic web application. Our app will put the custom Ruby gem developed in Chapter 8 to good use through the development of a web-based palindrome detector. Along the way, we’ll learn how to create dynamic content using embedded Ruby (ERB).

Detecting palindromes from the Web requires using a back-end web application to handle form submission, and our tool of choice is Sinatra, the micro-framework we met in Section 1.5 and applied further in Section 5.2. Although simple, Sinatra is not a toy—it’s a production-ready web framework used by companies like Stripe, Apple, and Disney.¹

¹ As of a few years ago, when I talked with a friend working ...