在我的Rails应用程序中,我试图为TrainingClass
模型设置创建表单。我希望此表单允许用户在同一表格中创建多个ClassMeeting
模型(与TrainingClass
模型具有belongs_to关系),并且我使用accepts_nested_attributes_for
来执行此操作。不幸的是,无论何时提交表单,我都会收到错误消息:Meetings class can't be blank
。在Rails中,如何使用accept_nested_attributes_for创建嵌套对象?
我意识到,这是因为ClassMeeting
有validates :class_id, presence: true
,因为TrainingClass
不能有一个ID,直到它被保存后,但我不知道以正确的方式来解决这个问题。 (我可以想到一些可能的方法,但它们并不完全是优雅的解决方案。)任何想法?我会很感激你能给我的任何帮助。
注意:我意识到过去有人问过类似这样的几个问题。然而,这些问题中的大部分都是陈旧的,并且已经过时了,他们都没有解决我的问题。
这是我的代码。请记住,虽然我已经简化为简洁它的某些方面,ClassMeeting
和TrainingClass
模型之间的关系保持不变:
ClassMeeting型号:
# == Schema Information
#
# Table name: class_meetings
#
# id :integer not null, primary key
# class_id :integer
# start :datetime
# end :datetime
# location :string(255)
# created_at :datetime not null
# updated_at :datetime not null
#
class ClassMeeting < ActiveRecord::Base
attr_accessible :start, :end, :location
validates :class_id, presence: true
validates :start, presence: true
validates :end, presence: true
validates :location, presence: true, length: {maximum: 255}
belongs_to :training_class, foreign_key: :class_id, inverse_of: :meetings
end
TrainingClass型号:
# == Schema Information
#
# Table name: training_classes
#
# id :integer not null, primary key
# description :string(255)
# created_at :datetime not null
# updated_at :datetime not null
#
class TrainingClass < ActiveRecord::Base
attr_accessible :description, :meetings_attributes
validates :description, length: {maximum: 255}
has_many :meetings, class_name: :ClassMeeting, foreign_key: :class_id, inverse_of: :training_class
accepts_nested_attributes_for :meetings, allow_destroy: true
end
训练类控制器:
class TrainingClassesController < ApplicationController
def new
@training_class = TrainingClass.new()
@training_class.meetings.build
end
def create
@training_class = TrainingClass.new()
if @training_class.update_attributes(params[:training_class])
redirect_to @training_class, notice: 'Class was successfully created.'
else
render "new"
end
end
end
TrainingClass表(视图):
<%= form_for @training_class do |f| %>
<%= render 'shared/error_messages', object: f.object %>
<%= f.text_area :description %>
<h2>Schedule</h2>
<%= f.fields_for :meetings do |meeting| %>
<%= meeting.label :start, "Start of Meeting:" %>
<%= meeting.text_field :start %>
<%= meeting.label :end, "End of Meeting:" %>
<%= meeting.text_field :end %>
<%= meeting.label :location, "Location:" %>
<%= meeting.text_field :location %>
<% end %>
<%= f.submit class:"btn btn-large btn-primary" %>
<% end %>