app.rb

require "rubygems"
require "crack"
require "json"
require "sinatra"
require "open-uri"

#    (c)2011 Nate Benes
#    Curbside JSON server
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.

get '/' do
  callback = params.delete('callback')
  lat = params.delete('lat')
  # lng? really? you just *had* to save the extra letter
  lng = params.delete('lng')
  if lat && lng # make sure we've got the required params
    # don't need to sanitize too much, we'll let OWH do that
    url = "http://services.dataomaha.com/omahaneighborhoods/xml/lng="+lng+"&lat="+lat
    # parse us some XML
    xmlResponse  = Crack::XML.parse(open(url).read)
    json = xmlResponse.to_json
    if callback # Its JSONP, wrap response in a function
      content_type :js
      response = "#{callback}(#{json})" 
    else # its a normal request
      content_type :json
      response = json
    end
  else # the user forgot a param or two
    response = '{"error":"malformed query"}'
  end  
  # return
  response

end