Question

In Rails 3.2.2, I want to setup custom URLs (using State 2 digit :abbr, instead of the default by :id)

Reading google results and stackoverflow pages, I’ve come up with this:

Routes

match 'cars/:abbr' => 'states#show', :as => 'state_abbr'

Model

def to_param
  abbr
end

Controller

@state = State.find_by_abbr(params[:id])

The state#show page is throwing out errors (undefined method `fullname’ for nil:NilClass), because the routing does not seem to be finding the abbr in the model.

Running rake routes, I get:

 root  /                    states#index
 state_abbr  /cars/:abbr(.:format) states#show

Thanks for your help

Answer 1

You want to use params[:abbr] not params[:id]. If you want to use :id change your route to be 'cars/:id' instead of 'cars/:abbr'