jQuery checkbox + getJSON

jquery

  $('#go_btn').click(function(event){
    var params = [];
    $("input:checkbox[name='selector']:checked").each(function(){
      params.push($(this).val());
    });
    $.getJSON('/results/'+params.join(':'), function(json){
      $('#results').html("<p>"+json.evalclaims+"</p>"+"<p>"+json.claims+"</p>");
    });
  });    

controller

get '/results/:params' do |params|
  redirect '/' unless request.xhr?
  requests = params.split(':')
  q = {}
  unless requests.empty?
    pf = PatentFile.new('./public/tmpfile')
    requests.each do |res|
      case res
      when 'evalclaims'
        q[:evalclaims] = pf.eval_claims_with_statics.last[:claims]
      when 'claims'
        q[:claims] = pf.claims 1
      end
    end
  end
  content_type :json
  {:evalclaims => q[:evalclaims], :claims => q[:claims]}.to_json
end