Mapping routes to layouts in Sinatra, help me clean this up - ruby-on-rails

Question

I'm a front end guy getting more and more into using sinatra. I'm building an app currently and am trying to find an elegant way to DRY up the routes in my myapp.rb file.
Currently I have these routes:
get '/' do
haml :content
end
get '/content' do
haml :content, :layout => :empty
end
get '/show_layout' do
haml :show_layout
end
get '/conversion' do
haml :conversion, :layout => :empty
end
get '/optout' do
haml :optout, :layout => false
end
get '/terms' do
haml :terms, :layout => :empty
end
With regards to the templates, I know I can do something like this to combine them:
get '/:name' do
haml params[:name].to_sym
end
But what about the layouts? There are only 2 layouts here, layout.haml and empty.haml (:layout, and :empty), 3 if you count :layout => false
Is this something that is best done using a hash? Something like:
layout_map = {
"" => "",
:content => "",
:show_layout => "",
:conversion => :empty,
:optout => false,
:terms => :empty
}
get '/:name' do
haml params[:name].to_sym, :layout => layout_map[:name]
end
Seems like its on the right track but I can't get it to work properly.
Thanks for all your help.

Answer 1

You can use your:
get '/:name' do
haml params[:name].to_sym
end
plus a before route that will set your layout:
before '/:name' do
layout_map = {
:content => "",
:show_layout => "",
:conversion => :empty,
:optout => false,
:terms => :empty
}
set :layout => layout_map[params[:name]]
end
This will set your layout according to params[:name] with every call. But be careful with .simming every route. If someone calls many 404s you create lots and lots of dead symbols which are not garbage collected and eventually will crash your app. Better do this:
get '/:name' do
halt 404 unless File.exist?("views/#{params[:name]}.haml")
time = File.stat("views/#{params[:name]}.haml").ctime
last_modified(time)
haml params[:name].intern
end
This will only create a symbol for params[:name] if there is a file with that name. So you're on the safe side because the symbol already exists.

Answer 2

Thanks for all your help everyone. Ended up going with this as my solution due to some other requirements of the app.
get "/:base_route/" do
haml :"#{params[:base_route]}/content", :layout => :"#{params[:base_route]}/layout"
end
get "/:base_route/:name" do
layout_map = {
:landing => :layout,
:content => :empty,
:show_layout => :layout,
:conversion => :empty,
:terms => :empty
}
haml :"#{params[:base_route]}/#{params[:name]}", :layout => :"#{params[:base_route]}/#{layout_map[params[:name].to_sym]}"
end