在rails_admin中使用orderable获取rails 4中的has_many：through关系

Question

我正在尝试弄清楚如何使用位置，如https://github.com/sferik/rails_admin/wiki/Has-many-%3A through-association中的示例所示，但不使用受保护的属性，而是使用Rails 4的强大参数。 如果我尝试使用没有attr_accessible :block_ids的页面上给出的block_ids=函数，我会收到一条带有unknown attribute :block_ids的ActiveRecord::UnknownAttributeError错误unknown attribute :block_ids 。 显然，如果我使用attr_accessible :block_ids ，它会要求我将protected_attributes添加到我的Gemfile中，这不是Rails 4方式。

有没有人能够使用强参数在rails_admin中为Rails 4制作可订购位置？

Answer 1

省略attr_accessible :block_ids并在底部应用替代解决方案对我attr_accessible :block_ids 。

PS：Rails 4.2.0，rails_admin为0.6.6

class Grid < ActiveRecord::Base
  has_many :block_grid_associations, :dependent => :delete_all, :autosave => true, :include => :block
  has_many :blocks, :through => :block_grid_associations

  def block_ids=(ids)
    unless (ids = ids.map(&:to_i).select { |i| i>0 }) == (current_ids = block_grid_associations.map(&:block_id))
      (current_ids - ids).each { |id| block_grid_associations.select{|b|b.block_id == id}.first.mark_for_destruction }
      ids.each_with_index do |id, index|
        if current_ids.include? (id)
          block_grid_associations.select { |b| b.block_id == id }.first.position = (index+1)
        else
          block_grid_associations.build({:block_id => id, :position => (index+1)})
        end
      end
    end
  end

  rails_admin do
    configure :block_grid_associations do
      visible(false)
    end

    configure :blocks do
      orderable(true) # only for multiselect widget currently. Will add the possibility to order blocks
      # configuration here
    end
  end
end