audits_controller.rb

class AuditsController < ApiController
  
  def index
       
    @audits = current_member.audit_responses.where('updated_at IS NULL').map{ |ar| ar.audit.attributes }.uniq
      
    respond_with @audits
        
  end   
        
  def respond
    if params[:audit]
        
      id = params[:audit][:id]
      
      if Audit.exists?(:id => id)
        audit = Audit.find(id)
        
        audit.update_attributes(params[:audit])
        audit_json = { "created" => [], "updated" => [audit.id], "deleted" => [], "attributes" => { audit.id => audit } }
      else
        audit = Audit.create(params[:audit])
        audit_json = { "created" => [audit.id], "updated" => [], "deleted" => [], "attributes" => { audit.id => audit } }
      end 
          
      if audit.is_survey
        audit.audit_responses.where("user_id = ? AND custom_form_question_id IS NOT NULL", current_member.id).each { |r| r.accepted_at = Time.new; r.save }
      end   
            
      if audit.save
        deleted = AuditResponse.where(:user_id => current_member.id, :audit_id => audit.id, :updated_at => nil).destroy_all
            
        render(:json => {
          "changeset" => { 
              
            "sc_version" => 2,
            "sc_types" => ["Evaluation", "EvaluationResponse"],
            
            "Evaluation" => audit_json,
        
            "EvaluationResponse" => {
              "created" => [],
              "updated" => [],
              "deleted" => deleted.map{ |ar| ar.id },
              "attributes" => {},
            }
        
          }
        }, :status => 200) and return
      else
        render(:json => audit.errors, :status => 500) and return
      end     
    end     
            
    render(:json => { :message => "audit must be provided" }, :status => 500) and return
  end       
        
end  

config.rb

...

    # Audit requests
    get '/audits(.:format)', :to => 'audits#index'
    post '/audits(.:format)', :to => 'audits#respond'

...