Rails nested_form无效的关联.确保使用accepts_nested_attributes_for进行联合 [英] Rails nested_form Invalid association. Make sure that accepts_nested_attributes_for is used for assoctiation
问题描述
我正在使用带有nested_form 0.3.2的Rails 4.0.4来构建一个允许用户组织列表中电影的应用程序.
I am using rails 4.0.4 with nested_form 0.3.2 to build an app that allows users to organize movies in lists.
我有以下主要模型,即List模型(我已经排除了诸如验证之类的东西):
I have these main models, a List model (I've excluded things such as validations):
class List < ActiveRecord::Base
belongs_to :user
has_many :list_movie_pairs
has_many :movies, :through => :list_movie_pairs
accepts_nested_attributes_for :list_movie_pairs, :allow_destroy => true
accepts_nested_attributes_for :movies, :allow_destroy => true
end
电影模型:
class Movie < ActiveRecord::Base
has_many :list_movie_pairs
has_many :lists, :through => :list_movie_pairs
has_many :reviews
end
用于多对多关系的ListMoviePair模型:
A ListMoviePair model for the many-to-many relationship:
class ListMoviePair < ActiveRecord::Base
belongs_to :list
belongs_to :movie
validates_presence_of :list_id, :movie_id
validates_uniqueness_of :movie_id, scope: :list_id
end
我正在尝试为用户构建一个界面,以将电影添加到创建的列表中.这些路线符合我的目的:
I am trying to build an interface for the user to add movies to a created list. These routes serve my purpose:
get "/users/:username/lists/:id/add" => "lists#add_movies", :as => :user_list_list_movie_pairs
post "/users/:username/lists/:id/add" => "lists#submit_movies"
这些是我的ListsController中的类,应该可以实现以下目的:
These are the classes in my ListsController that should make this possible:
def add_movies
@pair = list.list_movie_pairs.new # "list" is a helper that returns the current list
end
def submit_movies
@list = current_user.lists.find(params[:id])
@pair = @list.list_movie_pairs.new(pair_params)
if @pair.save
redirect_to user_list_path(current_user.username, @list)
else
render :add_movies
end
end
def list_params
params.require(:list).permit(:name, :description, :private, \
list_movie_pairs_attributes: [:id, :list_id, :movie_id, :_destroy], \
movies_attributes: [:id, :title, :_destroy])
end
这是我认为的形式
<%= nested_form_for [current_user, list, @pair] do |f| %>
<%= f.fields_for :movies do |movie_form| %>
<%= movie_form.text_field :title %>
<%= movie_form.link_to_remove "Remove movie" %>
<% end %>
<%= f.link_to_add "Add movie", :movies %>
<% end %>
尝试访问视图时出现此错误:
I get this error when trying to access the view:
无效的关联.确保:movies关联使用了accepts_nested_attributes_for.
Invalid association. Make sure that accepts_nested_attributes_for is used for :movies association.
在此行弹出:
<%= f.link_to_add "Add movie", :movies %>
注1:我正在为用户使用Devise gem,因此使用了"current_user"帮助程序;
Note 1: I am using the Devise gem for users, hence the "current_user" helper;
注2:我尝试同时使用电影"和"list_movie_pairs",即:
Note 2: I have tried using both "movies" and "list_movie_pairs", i.e.:
:list_movie_pairs的f.fields
f.fields for :list_movie_pairs
和
f.link_to_add添加电影":list_movie_pairs
f.link_to_add "Add movie", :list_movie_pairs
在我看来,这两个关联似乎都不起作用
in my view, neither association seems to work
推荐答案
您在视图中的代码应像这样
Your code in the view should be like this
<%= nested_form_for [current_user, list, @pair] do |f| %>
<%= f.fields_for :movies do |movie_form| %>
<%= movie_form.text_field :title %>
<%= movie_form.link_to_remove "Remove movie" %>
<%= movie_form.link_to_add "Add movie", :movies %> #note the change here
<% end %>
<% end %>
更新
您的代码中有几个问题
1.在您的List
模型中,不需要此行
1.In your List
model,this line is not required
accepts_nested_attributes_for :movies, :allow_destroy => true #not requied
2.在您的ListsController
中,您有这行
2.In your ListsController
,you have this line
@pair = @list.list_movie_pairs.new(pair_params)
应该是
@pair = @list.list_movie_pairs.new(list_params)
,因为您使用的是list_params
方法而不是pair_params
@pair = @list.list_movie_pairs.new(list_params)
because you have list_params
method not pair_params
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