Question

I am working on a Rails app, and I am looking for a way to route to different actions in the controller based on the existence of parameters in the url.

For example I want website.com/model to route to model#index, however I want website.com/model?opt=dev to route to model#show. Is there some way this can be done?

Answer 1

Use route constraints to look at the request object and see if it has URL parameters. If you’re using restful routes, you want to put this “one-off” before the restful route. Something like this:

get 'users' => 'users#show', constraints: { query_string: /.+/ }
resources :users

So what this is saying is that if you request “/users?opt=dev” then it will match your special case. Otherwise, it falls through to your normal restful route to the index action. Your model#show action will then have to know to pick up the param[:opt] and do whatever with it.

Also, note that the regex is very loose and it’s simply checking for ANY param…you’ll want to tighten that up to fit whatever you’re trying to do.