Rack Rocks!

Rack is the underlying technology behind Ruby web applications. This is an introduction to rack talk given at Myanmar Ruby Geeks Meetup #2 , Feb, 2016.

1. Rack Rocks! Chan Myae San Hlaing Facebook: Chan Myae San Hlaing Twitter: @jjrofriloc Github: @dreamingblackcat Freelance Developer at toptal.com
2. The Web
3. Web Applications
4. Ruby Web Servers Ruby Web Frameworks
5. Ruby Web Servers Ruby Web Frameworks
6. Rack • Inspired from Python WSGI spec • Both Spec and Implementation • Middleware Pattern
7. As Simple As Rack • Accept an env • Fiddle With It (or not) • Pass It to The Next Rack / Generate a Response • *Must Respond to #call method (yeah just like a Proc )
8. Hello World
9. What's in the env?
10. What makes rack cool?! • Middlewares can be stacked • Acts as filters for HTTP req/res • Common API for accessing req/res • No more interface code for web servers • Middlewares can be mounted on each other • Interoperability between Rack-based Frameworks
11. Types of Rack Middlewares • Inbound Filters • Outbound Filters • Endpoints
12. Inbound Filters • Modify Request (Headers, Parameters, Uploaded Files, Access Control, Logging, Analytics etc.)
13. Outbound Filters • Modify Response (Headers, Body, Redirection, Logging etc.)
14. Endpoints • Responds a valid http response [status, headers, body ] • Handling errors • Application Endpoints • Another Stack of Rack Middlewares • Eg. Any Rails Controller Action/ Sinatra Route Block
15. Endpoints
16. Rack Builder • A DSL for declaring rack middlewares • Comes built-in with rack gem
17. Rails is built on top of Rack http://guides.rubyonrails.org/rails_on_rack.html
18. List of Rack Middlewares • Rack::Attack • Rack:GoogleAnalytics • Rack::Cache • Warden • Rack::Throttle • And many more.... https://github.com/rack/rack/wiki/List-of-Middleware
19. • Minimalist Web Application Framework built on top of Rack • Encourage usage of Rack Middlewares • Highly Customizable • You will learn a lot about foundations of rails
20. Make your own Rack Middleware • A simple class that accepts an app variable in initialize • Define a method #call • Use Rack::Request and Rack::Response classes to access req/res • Read other middlewares' source codes, *Seriously it's just a simple ruby class usually.
21. Shameless Plug • A rack middleware to convert all incoming burmese inputs to Unicode • Used mmfont gem by @yelinaung and font detection code by @thuyamyonyunt • http://github.com/dreamingblackcat/mmunicode _rails
22. References • http://confreaks.tv/videos/mwrc2010-rack-for-w eb-developers • http://confreaks.tv/videos/rubyweb2010-the-po wer-of-middleware-building-your-own-mini-web- framework-on-rack • http://confreaks.tv/videos/larubyconf2012-rack -middleware-as-a-general-purpose-abstraction • http://confreaks.tv/videos/scotlandruby2011-rea l-time-rack • http://www.slideshare.net/DonSchado/froscon-r ack
23. Questions?
24. Thank You!