How do I set HTTParty configuration parameters on my class dynamically?

Question

The simple_client.rb file below works perfectly fine against my emulation cas server; however, the casport.rb file (main file of oa-casport OmniAuth strategy) is not setting or passing the headers / format properly. It needs to be dynamically assigned to the class to allow initializer options to be able to create them, but I'm not sure how else to do it besides how I've attempted to do it here. I was fairly certain I had this working at some point, but I can't see any other explanation for why this wouldn't be working given the simplicity of the client file.

Any help is greatly appreciated on figuring out how to best set the format and headers settings for HTTParty within my Casport class dynamically. As it is it just keeps returning the HTML view for that particular user.

simple_client.rb:

### simple_client.rb - works properly w/ parsed XML response
### The cas.dev project is coming from this Github repo:
### https://github.com/stevenhaddox/oa-casport-server
require 'rubygems'
require 'httparty'
require 'awesome_print'

class Casport
  include HTTParty
  base_uri 'cas.dev/users'
  format :xml
  headers 'Accept' => 'application/xml'

  def self.find_user(id)
    get("/#{id}").parsed_response
  end

end

user = Casport.find_user(1)
ap user

casport.rb:

# lib/omniauth/strategies/casport.rb
require 'omniauth/core'
require 'httparty'
require 'redis'
require 'uri'

module OmniAuth
  module Strategies
    #
    # Authentication to CASPORT
    #
    # @example Basic Usage
    #
    #  use OmniAuth::Strategies::Casport, {
    #        :setup       => true
    #      }
    # @example Full Options Usage
    #
    #  use OmniAuth::Strategies::Casport, {
    #        :setup         => true,
    #        :cas_server    => 'http://cas.slkdemos.com/users/',
    #        :format        => 'xml',
    #        :format_header => 'application/xml',
    #        :ssl_ca_file   => 'path/to/ca_file.crt',
    #        :pem_cert      => '/path/to/cert.pem',
    #        :pem_cert_pass => 'keep it secret, keep it safe.'
    #      }
    class Casport

      include OmniAuth::Strategy
      include HTTParty

      def initialize(app, options)
        super(app, :casport)
        @options = options
        @options[:cas_server]    ||= 'http://cas.dev/users'
        @options[:format]        ||= 'xml'
        @options[:format_header] ||= 'application/xml'
      end

      def request_phase
        Casport.setup_httparty(@options)
        redirect(callback_path)
      end

      def callback_phase
        begin
          raise 'We seemed to have misplaced your credentials... O_o' if user.nil?
          super
        rescue => e
          redirect(request_path)
#          fail!(:invalid_credentials, e)
        end
        call_app!
      end

      def auth_hash
        # store user in a local var to avoid new method calls for each attribute
        # convert all Java camelCase keys to Ruby snake_case, it just feels right!
        user_obj = user.inject({}){|memo, (k,v)| memo[k.gsub(/[A-Z]/){|c| '_'+c.downcase}] = v; memo}
        begin
          user_obj = user_obj['userinfo']
        rescue => e
          fail!(:invalid_user, e)
        end
        OmniAuth::Utils.deep_merge(super, {
          'uid'       => user_obj['uid'],
          'user_info' => {
                          'name' => user_obj['full_name'],
                          'email' => user_obj['email']
                         },
          'extra'     => {'user_hash' => user_obj}
        })
      end

      # Set HTTParty params that we need to set after initialize is called
      # These params come from @options within initialize and include the following:
      # :ssl_ca_file - SSL CA File for SSL connections
      # :format - 'json', 'xml', 'html', etc. || Defaults to 'xml'
      # :format_header - :format Header string || Defaults to 'application/xml'
      # :pem_cert - /path/to/a/pem_formatted_certificate.pem for SSL connections
      # :pem_cert_pass - plaintext password, not recommended!
      def self.setup_httparty(opts)
        format opts[:format].to_sym
        headers 'Accept' => opts[:format_header]
        if opts[:ssl_ca_file]
          ssl_ca_file opts[:ssl_ca_file]
          if opts[:pem_cert_pass]
            pem File.read(opts[:pem_cert]), opts[:pem_cert_pass]
          else
            pem File.read(opts[:pem_cert])
          end
        end
      end

      def user
        # Can't get user data without a UID from the application
        begin
          raise "No UID set in request.env['omniauth.strategy'].options[:uid]" if @options[:uid].nil?
          @options[:uid] = @options[:uid].to_s
        rescue => e
          fail!(:uid_not_found, e)
        end

        url = URI.escape(@options[:cas_server] + '/' + @options[:uid])
# It appears the headers aren't going through properly to HTTParty...
# The URL + .xml works in the application & the url w/out .xml works in standalone file
# Which means somehow the setup with self.setup_httparty isn't kicking in properly :(
ap Casport.get(url+'.xml').parsed_response 
        begin
          cache = @options[:redis_options].nil? ? Redis.new : Redis.new(@options[:redis_options])
          unless @user = (cache.get @options[:uid])
            # User is not in the cache
            # Retrieving the user data from CASPORT
            # {'userinfo' => {{'uid' => UID}, {'fullName' => NAME},...}},
            @user = Casport.get(url).parsed_response
            cache.set @options[:uid], @user
            # CASPORT expiration time for user (24 hours => 1440 seconds)
            cache.expire @options[:uid], 1440
          end
        # If we can't connect to Redis...
        rescue Errno::ECONNREFUSED => e
          @user ||= Casport.get(url).parsed_response
        end
        @user = nil if user_empty?
        @user
      end

      # Investigate user_obj to see if it's empty (or anti-pattern data)
      def user_empty?
        is_empty = false
        is_empty = true if @user.nil?
        is_empty = true if @user.empty?
        # If it isn't empty yet, let's convert it into a Hash object for easy parsing via eval
        unless @user.class == Hash
          is_empty = true
          raise "String returned when a Hash was expected."
        end
        is_empty == true ? true : nil
      end

    end
  end
end

Answer 1

This was apparently working properly, what I failed to do was to provide the header for Content-Type:

...
def self.setup_httparty(opts)
format opts[:format].to_sym
headers 'Accept' => opts[:format_header]
headers 'Content-Type' => opts[:format_header]
...

Once I added that additional line everything kicked in properly.