URL in Rails

Fundamental importance of the URI/URL

• URI = “Uniform Resource Identifier”
  • Used to be called “Universal Resource Locator” (URL)
  • Because the resources were files on the disk of the server
  • And the URL’s path was really a path!
• Focus now on the ‘path’ part of the URI
• e.g. some ugly examples
  • http://roomscheduler.com/reserve/room/3
  • http://bookstore/gonewiththewind/order/3
  • http://nyt.com/latest-updates?year=2014
• e.g. some good examples
  • http://roomscheduler.com/room/3/request
  • http://bookstore.com/book/412/price
  • http://tourmanager.com/city/boston/tour/tuesday/new
• There are many ways to structure a url

RESTful style of URI design

• “Representational State Transfer” (See Original REST Paper)
• Each URI denotes a specific ‘resource’
  • ‘room 3’ or ‘book 412’ or ‘tuesday tours IN Boston city’
  • It is usually not a file but something generated ‘on the fly’
  • Still the same URI should yield the same resource every time (handwave)
• Each URI is used in combination with an HTTP “method”
  • Get: retrieve the indicated “resource”
  • Put: update value of the indicated resource
  • Delete: delete the indicated resource
  • Post: Create a new instance of indicated resource
  • (some other, less important ones)

One of the earliest design questions

• What do the URLs for my app look like?
• Conceptually, they are “directory structure-like” URLs
• There is a coherent “syntax” about them, e.g.
  • http://www.myservice.org/discussion/topics/{topic}
  • http://www.myservice.org/discussion/2008/12/10/{topic}
  • http://www.myservice.org/discussion/{year}/{day}/{month}/{topic}
• Touchpoints, coming soon:
  • rails generate resource
  • rails routes
  • default controllers
  • In other words, you don’t have to follow this form of URL but…
  • You really should follow it because a lot of things fall into place.

Appendix

• Rails Routing Guide
• RESTful Web Services: The Basics