Question

我试图在我的控制器中为根对象（项目）添加对象数组（在这种情况下为任务）作为返回类型。一个项目有很多任务，我想一次全部保存，但是我不断收到以下错误，表明返回类型不正确。

ActiveRecord::AssociationTypeMismatch (Task(#47457277775360) expected, got {"name"=>"Some task", "start"=>"2019-12-05T03:38:48.555Z", "end"=>"2019-12-14T03:38:48.555Z"} which is an instance of ActiveSupport::HashWithIndifferentAccess(#47457266882220))

我列入白名单的参数就是这样

# whitelist params
params.permit(:name, :description, tasks: [:name, :start, :end])

以上示例返回的数据：

{"name"=>"asdf", "description"=>"zxvccxvzzxcvxcvcxvzxcvz", "tasks"=>[{"start"=>"2019-12-05T03:38:48.555Z", "end"=>"2019-12-14T03:38:48.555Z", "name"=>"Some task"}]}

[编辑]-这是我们正在使用的模型

# app/models/task.rb
class Task < ApplicationRecord
  # model association
  belongs_to :project

  # validation
  validates_presence_of :name
end

# app/models/project.rb
class Project < ApplicationRecord
  # model association
  has_many :tasks, dependent: :destroy
  accepts_nested_attributes_for :tasks

  # validations
  validates_presence_of :name
end

Answer 1

根据rails文档Nested attributes allow you to save attributes on associated records through the parent。因此，在强大的参数中，您需要传递这样的属性。

params.permit(:name, :description, task_attributes: [:name, :start, :end])

我建议您将所有参数绑定在一个这样的属性下

params.require(:project).permit(:name, :description, task_attributes: [:name, :start, :end])

所以您必须像

这样从前端发送参数

{"project": {"name"=>"asdf", "description"=>"zxvccxvzzxcvxcvcxvzxcvz", "task_attributes"=>[{"start"=>"2019-12-05T03:38:48.555Z", "end"=>"2019-12-14T03:38:48.555Z", "name"=>"Some task"}]}}

您可以阅读https://api.rubyonrails.org/classes/ActiveRecord/NestedAttributes/ClassMethods.html

中的文档

无法将我的强大参数正确嵌套在Ruby on Rails中

1 个答案: