Active resource complaining about expects an hash

activeresource, ruby, ruby-on-rails, ruby-on-rails-3

Solution

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.

Problem

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.

Original source