routes-and-REST.md

Routes & REST

Named Routes

We've seen the basic syntax for creating a route within an application, in the routes.rb:

get "/pineapple", to: "home#index"

Let's imaging a problematic scenario. We have a large application, 20+ pages, which includes the above route. This pineapple route is linked to on many of the pages, and from many controllers using redirect_to. What if Snapple™ decided to sponsor, they want this path changed to /pinesnapple. Now it is your job to track down every place where this link exists and change it. No fun.

Using a Named Route we can avoid this problem. By giving each route definition within the routes.rb a "name", we can then refer to it by name when creating links and redirects.

get "/pineapple", to: "home#index", as: :fruit

This creates a controller/view helper method, which generates the path for us, simply by referencing to the name. In a controller or view:

fruit_path # => "/pineapple"

note: The _path is added to the end of all named routes.

get "/pinesnapple", to: "home#index", as: :fruit
fruit_path # => "/pinesnapple"

REST

Representational state transfer (REST) is an architectural style. This is a recommendation for the structure and style in which a resource (ruby object) can be represented and managed through a web server.

The core of this idea can be described through routing. We'll look at an example if we have a Market object we want to represent through a web server.

PATH	METHOD	DESCRIPTION
/markets	GET	Retrieves a collection of market objects
	POST	Creates a market object on the server.
/markets/:id	GET	Retrieves an individual market object through an identifying attribute, given in the url path.
	PUT	Updates an individual market object through an identifying attribute, given in the url path.
	DELETE	Removes an individual market object through an identifying attribute, given in the url path.

You can see that many actions can be performed on a market object using only two paths. The paths represent the scope of the objects to operate on and the HTTP method indicates what type of action should be performed.

Named Routes for REST

Since the standard RESTful resource only requires to paths, all five actions can be represented by just the two named routes. The conventional route names for a RESTful resource would be markets_path and market_path

The new (and edit) pages of a resource are not considered part of REST, because those pages are not actually performing an action on the object, they are only setting up the client to be able to send a RESTful request (like POST or PUT)

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