Animal

Animal.txt

#!/usr/bin/env ruby
# coding: utf-8

require 'sinatra'

get '/:animal' do
  @all_animals = ['Cat', 'Dog']
  @animal = params[:animal] if @all_animals.include? params[:animal]
  erb :index
end

__END__

@@ index
<h1><%= @animal || 'Unknown animal' %></h1>
<% if @animal %>
  <img src="/<%= @animal %>.jpeg"/>
<% end %>
<% @all_animals.each do |animal| %>
  <a href="/<%= animal %>"><%= animal %></a>
<% end %>