boatshop resultitem class

  
  def validate params
    raise OURERROR if !(self.manufacturer == params[:manufacturer] and self.country_code and params[:country_code]  and self.model == params[:model])
  end

gistfile1.txt

 def show
    query_builder = ::Factory::query_builder
    
    api_response_hash = query_builder.get_item(params[:id], params[:item_type])

    raise ActionController::RoutingError.new 'Not Found' if api_response_hash[:items].blank?
    
    @result_item = ::Factory.create_result_item(api_response_hash['items'][0])
    
    @result_item.validate params
    
    add_breadcrumb({
        :link => result_items_url(:search => @search.to_hash),
        :title => @result_item.breadcrumb_title,
        :name => @result_item.breadcrumb_title,
      })

    initialize_prev_next_items unless @search.new_object
    
    initialize_lead @result_item

    rescue OURERROR
       redirect_to :internal_server_error_errors
    end

  end

OURERROR check models/api/errors and make your own.