Building with Rack

Let's build a Rack app!

Transcript

1. Building with Rack Alexander Clark
2. What is Rack?
3. ?
5. ?
7. ?
8. ?
9. What does a Rack app look like? ?
10. What does a Rack app look like? GET /foo HTTP/1.1 Host: localhost:9292 Accept: text/html … ?
11. What does a Rack app look like? GET /foo HTTP/1.1 Host: localhost:9292 Accept: text/html … ? <!DOCTYPE html> <html> <head> …
12. run Proc.new { |env| ['200', {'Content-Type' => 'text/html'}, ['get rack\'d']] }
13. run Proc.new { |env| ['200', {'Content-Type' => 'text/html'}, ['get rack\'d']] } Responds to #call HTTP Status code Headers Response body Run
14. run Proc.new { |env| ['200', {'Content-Type' => 'text/html'}, ['get rack\'d']] } Responds to #call Much HTTP Status code Such Headers Response body Wow Run
15. Let’s build something!
17. <!DOCTYPE html> <html> <head> <title>Is it April Fools?</title> </head> <body> <h1><%= @april_fools ? 'YES' : 'NO' %></h1> </body> </html>
18. require 'erb' class MyRackApp def initialize @april_fools = Time.now.strftime('%m%d') == '0401' end def call(_env) ['200', {'Content-Type' => 'text/html'}, view] end def view [ERB.new(template).result(binding)] end def template File.open('index.html.erb', 'r').read end end
19. require './my_rack_app' run MyRackApp.new
21. ?
22. run Proc.new { |env| ['200', {'Content-Type' => 'text/html'}, ['get rack\'d']] } run MyRackApp.new ... def call(_env) ['200', {'Content-Type' => 'text/html'}, view] end
23. run MyRackApp.new run Rails.application
24. Middleware
25. TL;DL
26. Further Reading • https://rack.github.io/ • http://alexander-clark.com/blog/building-a-rack-app/ • http://www.justinweiss.com/articles/a-web-server-vs- an-app-server/ • https://www.amberbit.com/blog/2011/07/13/ introduction-to-rack-middleware/
27. Thanks for Listening Alexander Clark atheclark alexander-clark.com alexander-clark