Active resource complaining about expects an hash - ruby-on-rails

Question

I am using active resource to get data from an api and display it,
My controller model.rb has
class Thr::Vol::Dom < ActiveResource::Base
class << self
def element_path(id, prefix_options = {}, query_options = nil)
prefix_options, query_options = split_options(prefix_options) if query_options.nil?
"#{prefix(prefix_options)}#{collection_name}/#{id}#{query_string(query_options)}"
end
def collection_path(prefix_options = {}, query_options = nil)
prefix_options, query_options = split_options(prefix_options) if query_options.nil?
"#{prefix(prefix_options)}#{collection_name}#{query_string(query_options)}"
end
end
ActiveResource::Base.site = 'http://10.00.0.00:8888/'
self.format = :json
self.collection_name= "/vv/test/domains"
def self.find
x = superclass.find(:one, :from => '/vv/test/domains/2013-06-25T05:03Z')
x
end
end
When i call this Thr::Vol::Dom.find method it returns the following error:
ArgumentError: expected an attributes Hash,
got ["0.0.0.0", "1.1.1.1", "2.2.2.2", "3.3.3.3", "4.4.4.4"]
The api is expected to feed something like this
{"abs.com":["0.0.0.0", "1.1.1.1", "2.2.2.2", "3.3.3.3", "4.4.4.4"]}
for the call i made.
The API returns the correct hash but i guess active resource is not able to read it properly, it is directly reading the value in the key-value pair of the hash.
I want to fix this "ArgumentError" error , i want to display the contents of the returned hash in the view.

Answer 1

You can change how ActiveResource handle json response with
class YourModel < ActiveResource::Base
self.format = ::JsonFormatter.new(:collection_name)
end
In lib/json_formatter.rb
class JsonFormatter
include ActiveResource::Formats::JsonFormat
attr_reader :collection_name
def initialize(collection_name)
#collection_name = collection_name.to_s
end
def decode(json)
remove_root(ActiveSupport::JSON.decode(json))
end
private
def remove_root(data)
if data.is_a?(Hash) && data[collection_name]
data[collection_name]
else
data
end
end
end
If you pass self.format = ::JsonFormatter.new(:categories) it will find and remove categories root element in your json returned by your API.

Answer 2

The API is returning a JSON object, not a Ruby hash. You'll need to convert it into a hash by using Ruby's JSON module:
require 'JSON'
hash = JSON.parse('{"abs.com":["0.0.0.0", "1.1.1.1", "2.2.2.2", "3.3.3.3", "4.4.4.4"]}')
This will return a hash and then you'll notice that the key/value pair will work as expected:
hash["abs.com"] => ["0.0.0.0", "1.1.1.1", "2.2.2.2", "3.3.3.3", "4.4.4.4"]