Ruby Hash parsed_response error - ruby

Question

BACKGROUND
I am using HTTParty to parse an XML hash response. Unfortunately, when the hash response only has one entry(?), the resulting hash is not indexable. I have confirmed the resulting XML syntax is the same for single and multiple entry(?). I have also confirmed my code works when there are always multiple entries(?) in the hash.
QUESTION
How do I accommodate the single hash entry case and/or is there an easier way to accomplish what I am trying to do?
CODE
require 'httparty'
class Rest
include HTTParty
format :xml
end
def test_redeye
# rooms and devices
roomID = Hash.new
deviceID = Hash.new { |h,k| h[k] = Hash.new }
rooms = Rest.get(#reIp["theater"] + "/redeye/rooms/").parsed_response["rooms"]
puts "rooms #{rooms}"
rooms["room"].each do |room|
puts "room #{room}"
roomID[room["name"].downcase.strip] = "/redeye/rooms/" + room["roomId"]
puts "roomid #{roomID}"
devices = Rest.get(#reIp["theater"] + roomID[room["name"].downcase.strip] + "/devices/").parsed_response["devices"]
puts "devices #{devices}"
devices["device"].each do |device|
puts "device #{device}"
deviceID[room["name"].downcase.strip][device["displayName"].downcase.strip] = "/devices/" + device["deviceId"]
puts "deviceid #{deviceID}"
end
end
say "Done"
end
XML - SINGLE ENTRY
<?xml version="1.0" encoding="UTF-8" ?>
<devices>
<device manufacturerName="Philips" description="" portType="infrared" deviceType="0" modelName="" displayName="TV" deviceId="82" />
</devices>
XML - MULTIPLE ENTRY
<?xml version="1.0" encoding="UTF-8" ?>
<devices>
<device manufacturerName="Denon" description="" portType="infrared" deviceType="6" modelName="Avr-3311ci" displayName="AVR" deviceId="77" />
<device manufacturerName="Philips" description="" portType="infrared" deviceType="0" modelName="" displayName="TV" deviceId="82" />
</devices>
RESULTING ERROR
[Info - Plugin Manager] Matches, executing block
rooms {"room"=>[{"name"=>"Home Theater", "currentActivityId"=>"78", "roomId"=>"-1", "description"=>""}, {"name"=>"Living", "currentActivityId"=>"-1", "roomId"=>"81", "description"=>"2nd Floor"}, {"name"=>"Theater", "currentActivityId"=>"-1", "roomId"=>"80", "description"=>"1st Floor"}]}
room {"name"=>"Home Theater", "currentActivityId"=>"78", "roomId"=>"-1", "description"=>""}
roomid {"home theater"=>"/redeye/rooms/-1"}
devices {"device"=>[{"manufacturerName"=>"Denon", "description"=>"", "portType"=>"infrared", "deviceType"=>"6", "modelName"=>"Avr-3311ci", "displayName"=>"AVR", "deviceId"=>"77"}, {"manufacturerName"=>"Philips", "description"=>"", "portType"=>"infrared", "deviceType"=>"0", "modelName"=>"", "displayName"=>"TV", "deviceId"=>"82"}]}
device {"manufacturerName"=>"Denon", "description"=>"", "portType"=>"infrared", "deviceType"=>"6", "modelName"=>"Avr-3311ci", "displayName"=>"AVR", "deviceId"=>"77"}
deviceid {"home theater"=>{"avr"=>"/devices/77"}}
device {"manufacturerName"=>"Philips", "description"=>"", "portType"=>"infrared", "deviceType"=>"0", "modelName"=>"", "displayName"=>"TV", "deviceId"=>"82"}
deviceid {"home theater"=>{"avr"=>"/devices/77", "tv"=>"/devices/82"}}
room {"name"=>"Living", "currentActivityId"=>"-1", "roomId"=>"81", "description"=>"2nd Floor"}
roomid {"home theater"=>"/redeye/rooms/-1", "living"=>"/redeye/rooms/81"}
devices {"device"=>{"manufacturerName"=>"Philips", "description"=>"", "portType"=>"infrared", "deviceType"=>"0", "modelName"=>"", "displayName"=>"TV", "deviceId"=>"82"}}
device ["manufacturerName", "Philips"]
/usr/local/rvm/gems/ruby-1.9.3-p374#SiriProxy/gems/siriproxy-0.3.2/plugins/siriproxy-redeye/lib/siriproxy-redeye.rb:145:in `[]': can't convert String into Integer (TypeError)

Answer 1

There are a couple of options I see. If you control the endpoint, you could modify the XML being sent to accomodate HTTParty's underlying XML parser, Crack by putting a type="array" attribute on the devices XML element.
Otherwise, you could check to see what class the device is before indexing into it:
case devices["device"]
when Array
# act on the collection
else
# act on the single element
end
It's much less than ideal whenever you have to do type-checking in a dynamic language, so if you find yourself doing this more than once it may be worth introducing polymorphism or at the very least extracting a method to do this.