rails routes optional parameters types by :id or :name

Question

Scenario: I would like to have a url path where you could look someone up by an :id or :name:.
For user/5 or /user/tom would all point to the same user

routes.rb

controller 'user' do  
    get 'user/:id'  
    get 'user/:name'  
end 

test/routes/user_routes.rb

test "/user/:id" do  
  assert_routing "/user/5", :controller => "user", :action => "find_by_id", :id=>"5"  
end  

test "/user/:name" do  
  assert_routing "/user/tom", :controller => "user", :action => "find_by_name", :name=>"tom"  
end 

I am not exactly sure if this is the right design decision with URL paths.
Looking for guidance

Answer 1

I don't think what you are doing is going to work, because the routes you gave are ambiguous, because rails routes can't say that url like user/15 has name or id.

Of course there is a way to do this, by specifying regular expression. Since id will always be a number, we can have regular expression check for it

controller 'user' do  
    get 'user/:id', :id => /\d+/
    get 'user/:name', :name => /[A-Za-z][\w\s]+/
end 

The above statements put a constraint of regular expression. In your controller you can check like

if params[:id]
# Get by id
else
# Get by name

You can also do this by passsing get parameters and handling it in controller in the same way.

Thanks