Set site/user fields in ActiveResource

I am building a sinatra app that will use Highrise CRM gem to access Highrise data. This gem is based on ActiveResource class. I want to set site, user fields for every request. I followed suggestion posted here - Is it thread safe to set Active Resource HTTP authentication on a per-user basis?. I add code (shown below) and I get an error. Can anyone help understand this error and how to fix it.

class ActiveResource::Base
  class << self
    %w(site user).each do |attr|               

      define_method(attr) do
        Thread.current["active_resource.#{attr}"]
      end

      define_method("#{attr}=", val) do
        Thread.current["active_resource.#{attr}"] = val
      end
    end
  end
end

And the error:

c:/dev/hgadget/application.rb:18:in `block in singletonclass':
undefined local variable or method `val' for #<Class:ActiveResource::Base> (NameError)
    from c:/dev/hgadget/application.rb:12:in `each'
    from c:/dev/hgadget/application.rb:12:in `singletonclass'
    from c:/dev/hgadget/application.rb:11:in `<class:Base>'
    from c:/dev/hgadget/application.rb:9:in `<top (required)>'
    from <internal:lib/rubygems/custom_require>:29:in `require'
    from <internal:lib/rubygems/custom_require>:29:in `require'
    from application_test.rb:1:in `<main>'

------------------------update-----------------------------

I tried your suggestion, I now get this error.

NoMethodError - undefined method `path' for "https://test.abcd.com":String:
  c:/Ruby192/lib/ruby/gems/1.9.1/gems/activeresource3.0.11/lib/active_resource/base.rb:562:in `prefix'
  c:/Ruby192/lib/ruby/gems/1.9.1/gems/activeresource3.0.11/lib/active_resource/base.rb:667:in `collection_path'
  c:/Ruby192/lib/ruby/gems/1.9.1/gems/activeresource3.0.11/lib/active_resource/base.rb:856:in `find_every' 
  c:/Ruby192/lib/ruby/gems/1.9.1/gems/activeresource-3.0.11/lib/active_resource/base.rb:777:in `find' application.rb:78:in `block in <main>'
  c:/Ruby192/lib/ruby/gems/1.9.1/gems/sinatra-1.3.1/lib/sinatra/base.rb:1212:in `call'
  c:/Ruby192/lib/ruby/gems/1.9.1/gems/sinatra-1.3.1/lib/sinatra/base.rb:1212:in `block in compile!'
  c:/Ruby192/lib/ruby/gems/1.9.1/gems/sinatra-1.3.1/lib/sinatra/base.rb:772:in `[]'
  c:/Ruby192/lib/ruby/gems/1.9.1/gems/sinatra-1.3.1/lib/sinatra/base.rb:772:in `block (3 levels) in route!'
  c:/Ruby192/lib/ruby/gems/1.9.1/gems/sinatra-1.3.1/lib/sinatra/base.rb:788:in `route_eval'
  c:/Ruby192/lib/ruby/gems/1.9.1/gems/sinatra-1.3.1/lib/sinatra/base.rb:772:in `block (2 levels) in route!'
  c:/Ruby192/lib/ruby/gems/1.9.1/gems/sinatra-1.3.1/lib/sinatra/base.rb:821:in `block in process_route'

回答1:

I've been playing a lot with setting site option dynamically during runtime and the only solution I have found which will not lead to race condition.

class Runner
  def self.new(site)
    Class.new(ActiveResource::Base) do
      self.site = site
      self.element_name = 'runner'

      # your methods here
    end.new
  end
end

回答2:

While defining method with define_method you can specify its arguments passing them as arguments to the block and not to define_method itself. So you can define setter method like that:

define_method("#{attr}=") do |val|
  Thread.current["active_resource.#{attr}"] = val
end