Question

My aim is simply to display two optional URL parameters on an index page.

0.0.0.0:3000/comparison –> show: empty comparison index page

0.0.0.0:3000/comparison/3 –> show:

3

0.0.0.0:3000/comparison/3/4 –> show:

3
4 

I created a controller + view for “comparison”

rails generate controller comparison

and I added

match ':comparison/:index(/:a(/:b))'

to the routes.rb and added an index.html.erb displaying both parameters

<%= @a %>
<%= @b %>

my controller looks like this, simply forwarding the parameters to the view

class ComparisonController < ApplicationController
  def index 
    @a = params[:a]
    @b = params[:a]
  end
end

With this I am getting a routing error, e.g.

Routing Error

No route matches [GET] "/comparison/3/4"

How do I get the routing right?

Answer 1

Try this route (assuming Rails version 3.x):

match 'comparison(/:a(/:b))' => "comparison#index"