在Rails_admin中关联新范围/未保存记录的范围

Question

在Rails_admin wiki中，它们描述了关联范围如何起作用：

config.model Team do
  field :players do
    associated_collection_cache_all false  # REQUIRED if you want to SORT the list as below
    associated_collection_scope do
      # bindings[:object] & bindings[:controller] are available, but not in scope's block!
      team = bindings[:object]
      Proc.new { |scope|
        # scoping all Players currently, let's limit them to the team's league
        # Be sure to limit if there are a lot of Players and order them by position
        scope = scope.where(league_id: team.league_id) if team.present?
        scope = scope.limit(30).reorder('players.position DESC') # REorder, not ORDER
      }
    end
  end
end

然而，他们也提到：

  

另请注意，范围考虑了保存的版本   记录，不考虑你可能在中做出的任何未保存的更改   编辑表格。如果你改变球队的联赛，你仍然会看到   来自旧联盟的球员，直到你拯救。

使新的未保存记录的最佳方法是什么？因此，当我在表单中更改联赛时，玩家将相应地更新，而无需保存记录。