在我的Rails应用程序中,我正在尝试为TrainingClass
模型设置创建表单。我希望此表单允许用户在同一表单中创建多个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,每当我提交表单时,都会收到错误消息:Meetings class can't be blank
。
我意识到这是因为ClassMeeting
有validates :class_id, presence: true
,因为TrainingClass
在保存之前不能拥有ID,但我不确定正确的方法绕过这个。 (我可以想到几种可能的方法,但它们并不是完全优雅的解决方案。)任何想法?我很感激你能给我的任何帮助。
注意:我发现过去曾有过一些类似的问题。但是,大多数问题都是陈旧的,并且已经过时了,而且没有一个能解决我的问题。
这是我的代码。请注意,虽然为了简洁起见,我已简化了某些方面,但ClassMeeting
和TrainingClass
模型之间的关系却未受影响:
ClassMeeting模型:
# == 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模型:
# == 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
TrainingClasses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表单(查看):
<%= 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 %>
答案 0 :(得分:0)
好吧,我找到了解决问题的方法。我需要做的就是在ClassMeeting
模型中验证training_class的存在而不是class_id。这样,仍然可以验证培训课程的存在,但验证者不会干扰accepts_nested_attributes_for
保存模型的方法:
class ClassMeeting < ActiveRecord::Base
attr_accessible :start, :end, :location
validates :training_class, presence: true # :training_class instead of :class_id
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
答案 1 :(得分:0)
我仔细研究了这个例子,尝试了与我的代码的差异,但最后我的问题通过使用:inverse_of
来解决。
请参阅accepts_nested_attributes_for child association validation failing