def register_constraints_with_action_columns(constrained_fields = nil)
      constrained_fields ||= []
      constrained_fields |= active_scaffold_constraints.reject { |_, v| params_hash?(v) }.keys.collect(&:to_sym)
      exclude_actions = []
      %i[list update].each do |action_name|
        if active_scaffold_config.actions.include? action_name
          exclude_actions << action_name unless active_scaffold_config.send(action_name).hide_nested_column
        end
      end

      # we actually want to do this whether constrained_fields exist or not, so that we can reset the array when they don't
      active_scaffold_config.actions.each do |action_name|
        next if exclude_actions.include?(action_name)
        action = active_scaffold_config.send(action_name)
        next unless action.respond_to? :columns
        action.columns.constraint_columns = constrained_fields
      end
    end
def register_constraints_with_action_columns(constrained_fields = nil)
      constrained_fields ||= []
      constrained_fields |= active_scaffold_constraints.reject { |_, v| params_hash?(v) }.keys.collect(&:to_sym)
      exclude_actions = []
      %i[list update].each do |action_name|
        if active_scaffold_config.actions.include? action_name
          exclude_actions << action_name unless active_scaffold_config.send(action_name).hide_nested_column
        end
      end

      # we actually want to do this whether constrained_fields exist or not, so that we can reset the array when they don't
      active_scaffold_config.actions.each do |action_name|
        next if exclude_actions.include?(action_name)
        action = active_scaffold_config.send(action_name)
        next unless action.respond_to? :columns
        action.columns.constraint_columns = constrained_fields
      end
    end
For each enabled action, adds the constrained columns to the ActionColumns object (if it exists).
 This lets the ActionColumns object skip constrained columns.

 If the constraint value is a Hash, then we assume the constraint is a multi-level association constraint (the reverse of a has_many :through) and we do NOT register the constraint column.