如何显示在销毁记录之前将被删除的依赖记录

Question

Django admin向你展示了当你删除一条记录作为确认时将被删除的依赖记录。

是否有办法在Ruby on Rails上做同样的事情?

我一直在研究如何做这件事，但我仍在寻找方法。

Answer 1

我找不到宝石，所以我用关联反射来写这个问题:

module DependentDestroys
extend ActiveSupport::Concern
DEPENDENT_DESTROY_ACTIONS = %i[destroy delete destroy_async]
class_methods do
def dependent_destroy_reflections
@dependent_destroy_reflections ||= reflections.filter_map do |name, r|
r if DEPENDENT_DESTROY_ACTIONS.include?(r.options[:dependent])
end
end
end
def total_dependent_destroys
dependent_destroy_counts.sum { |r| r[1] }
end
def any_dependent_destroys?
dependent_destroy_counts.any?
end
# If you want all affected records...
def dependent_destroy_records
self.class.dependent_destroy_reflections.flat_map do |r|
relation = self.public_send(r.name)
if r.collection?
relation.find_each.to_a
else
relation
end
end
end
# If you only want the record type and ids...
def dependent_destroy_ids
self.class.dependent_destroy_reflections.flat_map do |r|
relation = self.public_send(r.name)
if r.collection?
relation.pluck(:id).map { |rid| [r.klass, rid] }
else
[[r.klass, relation.id]] if relation
end
end.compact
end
# If you only want counts...
def dependent_destroy_counts
self.class.dependent_destroy_reflections.filter_map do |r|
relation = self.public_send(r.name)
if r.collection?
c = relation.count
[r.klass, c] if c.positive?
else
[r.klass, 1] if relation
end
end
end
def dependent_destroy_total_message
"#{total_dependent_destroys} associated records will be destroyed"
end
def dependent_destroy_message
# Using #human means you can define model names in your translations.
"The following dependent records will be destroyed: #{dependent_destroy_ids.map { |r| "#{r[0].model_name.human}/#{r[1]}" }.join(', ')}"
end
def dependent_destroy_count_message
"The following dependent records will be destroyed: #{dependent_destroy_counts.map { |r| "#{r[0].model_name.human(count: r[1])} (#{r[1]})" }.join(', ')}"
end
end

用法:

class User
include DependentDestroys
belongs_to :company
has_many :notes
has_one :profile
end
user = User.first
user.any_dependent_destroys?
# => true
user.total_dependent_destroys
# => 60
user.dependent_destroy_total_message
# => "60 associated records will be destroyed"
user.dependent_destroy_message
# => "The following dependent records will be destroyed: Note/1, Note/2, ..., Profile/1"
user.dependent_destroy_count_message
# => "The following dependent records will be destroyed: Notes (59), Profile (1)"

您可以在控制器中使用这些方法来处理用户流。

通过一些改进，选项(比如将其限制为你想要的关联或模式(destroy, delete, destroy_async))和测试，这可能会成为一个gem。