How to route to a specific custom Rails 5 API version? - ruby-on-rails

Question

I'm developing an application which backend is being written in rails 5 api (beta version).
My API will have some versions, and I'm using this approach to address versioning:
https://github.com/iamvery/rails-api-example/blob/master/config/routes.rb
Rails.application.routes.draw do
def api_version(version, &routes)
api_constraint = ApiConstraint.new(version: version)
scope(module: "v#{version}", constraints: api_constraint, &routes)
end
api_version(1) do
resources :articles, only: :index
end
api_version(2) do
resources :articles, only: :index
end
end
The thing is when I don't specify a version, it shows me an (obviuos) error (ActionController::RoutingError: No route matches [GET] \...).
But I'd like to route using latest api version instead throwing an error.

Answer 1

Your routes.rb file
Rails.application.routes.draw do
scope module: :v1, constraints: ApiConstraints.new(version: 1, default: true) do
# Then for a new version create a new scope
end
end
Create a new api_constraints.rb file in the app/lib directory
class ApiConstraints
def initialize(options)
#version = options[:version]
#default = options[:default]
end
def matches?(req)
#default || req.headers['Accept'].include?("application/vnd.marketplace.v#{#version}")
end
end

Answer 2

I would add a root route, and use a simple redirect, like this:
root to: redirect('/api/v2')
I believe this could be done dynamically, by a little more change, something like this:
#versions = []
def api_version(version)
#versions << versions
# The rest of your code..
end
root to: redirect("/v#{#versions.max}")
I hope this helps.