Rails2，为什么这个控制器操作返回一个nil.to_sym

Question

以下是我的show操作: def show

    @category = Category.find_by_url_name(params[:id])
          @brands = @category.brands
          @categories = Category.find(:all)
          @meta_title = "#{@category.name}"

    respond_to do |format|
      format.html 
              @brand = @brands.first     
              @search = Product.search.order(params[:order] || 'descend_by_date')

              @products = @search.paginate(:conditions => { :category_id => @category, :brand_id => @brand }, :page => params[:page])      
              render :template => 'brands/show'

      format.xml  { render :xml => @category }
    end
  end

错误返回：

NoMethodError (You have a nil object when you didn't expect it!
The error occurred while evaluating nil.to_sym):
  searchlogic (2.5.8) lib/searchlogic/active_record/named_scope_tools.rb:16:in `named_scope_options'
  searchlogic (2.5.8) lib/searchlogic/named_scopes/alias_scope.rb:54:in `named_scope_options'
  searchlogic (2.5.8) lib/searchlogic/named_scopes/or_conditions.rb:14:in `named_scope_options'
  searchlogic (2.5.8) lib/searchlogic/search/scopes.rb:15:in `scope_options'
  searchlogic (2.5.8) lib/searchlogic/search/method_missing.rb:80:in `cast_type'
  searchlogic (2.5.8) lib/searchlogic/search/method_missing.rb:22:in `method_missing'
  searchlogic (2.5.8) lib/searchlogic/search/method_missing.rb:36:in `send'
  searchlogic (2.5.8) lib/searchlogic/search/method_missing.rb:36:in `method_missing'
  app/controllers/categories_controller.rb:28:in `show'
  app/controllers/categories_controller.rb:25:in `show'

我已经搞了一段时间了，现在还没有解决……

我正在使用rvm处理我的版本控制

gem -v = 1.5.3 Rails -v = 3.1.1 Ruby -v = 1.8.7

我想知道是不是rails版本的问题…有什么想法吗？

Answer 1

结果是几件事: Rails版本，需要指定2.3.x，是的，在散列中的条件...必须使其成为一个数组