有许多best_in_place在轨道4一对多的关系 [英] best_in_place with a many to many relationship in rails 4

问题描述

我已经一个GitHub库，你可以在这里找到的只是为这个问题。我有3个型号：

I have made a github repo that you can find here just for this question. I have 3 models:

class User < ActiveRecord::Base
  has_many :user_countries
  has_many :event_countries,
    -> { where(user_countries: {:event => true}) },
    :through => :user_countries,
    :source => :country
  has_many :research_countries,
    -> { where(user_countries: {:research => true}) },
    :through => :user_countries
    :source => :country
end

class UserCountry < ActiveRecord::Base
  belongs_to :country
  belongs_to :user
end

class Country < ActiveRecord::Base
  # ...
end

因此​​，一个用户应能选择event_countries和research_countries。

So a user should be able to choose event_countries and research_countries.

这里是我的用户控制器（没有什么复杂的）：

here's my users controller (nothing complicated):

 class UsersController < ApplicationController

  respond_to :html, :json
  before_action :get_user, only: [:show, :edit, :update]
  before_action :get_users, only: [:index]

  def index
  end

  def show
  end

  def edit
  end

  def update
    @user.update_attributes(user_params)
    respond_with @user
  end

  private

  def get_user
    @user = User.find(params[:id])
  end

  def get_users
    @users = User.all
  end

  def user_params
    params.require(:user).permit(:first_name, :event_countries => [:id, :name])
  end
end

这是我的用户显示页面：

And here's my user show page:

<%= best_in_place @user, :first_name %>

<p> event countries: </p>
<%= best_in_place @user, :event_countries, place_holder: "click here to edit", as: :select, collection: Country.all.map {|i| i.name} %>

<%= link_to "users index", users_path %>

所以没什么好说的，在这里复杂的。我也可以成功地编辑自己的用户名，best_in_place工作正常。

So there's really nothing complicated here. I can also succesfully edit my users first name, best_in_place is working fine.

现在的问题是：我怎么编辑event_countries？正如你可以看到我试图用同国家收集选项，但是当我尝试选择一个国家，我得到如下：

The question is: how do I edit the event_countries ? As you can see I tried to use the collection option with the countries but when I try to select a country I get the following:

    Processing by UsersController#update as JSON
  Parameters: {"user"=>{"event_countries"=>"3"}, "authenticity_token"=>"l5L5lXFmJFQ9kI/4klMmb5jDhjmtQXwn6amj1uwjSuE=", "id"=>"6"}
  User Load (0.1ms)  SELECT  "users".* FROM "users"  WHERE "users"."id" = ? LIMIT 1  [["id", 6]]
   (0.1ms)  begin transaction
   (0.1ms)  rollback transaction
Completed 500 Internal Server Error in 3ms

NoMethodError (undefined method `each' for nil:NilClass):
  app/controllers/users_controller.rb:17:in `update'

我不明白它在做什么，我知道它必须与收集选项的问题。如果你需要看到任何文件，请点击这里查看我的回购协议： https://github.com/spawnge/best_in_place_join_models_twice 。我有一个花了很多时间在这任何答案/建议，将大大AP preciated：）

I don't understand what it's doing, I know it must be a problem with the collection option. If you need to see any file please check my repo here: https://github.com/spawnge/best_in_place_join_models_twice . I have a spent a lot of time on this any answer/suggestion would be greatly appreciated :)

更新：

我已经试过这样：

<%= best_in_place @user, :event_country_ids, as: :select, collection: Country.all.map { |i| i.name }, place_holder: "click here to edit",  html_attrs: { multiple: true } %>

和我已经加入：event_country_ids到我的用户PARAMS：

and I have added :event_country_ids to my user params:

    params.require(:user).permit(:first_name, :event_country_ids)

现在我可以看到所有的国家，但是当我选择一个在这里就是我得到：

And now I can see all the countries but when I select one here's what I get:

Started PUT "/users/3" for 127.0.0.1 at 2014-12-18 01:19:27 +0000
Processing by UsersController#update as JSON
  Parameters: {"user"=>{"event_country_ids"=>"1"}, "authenticity_token"=>"aZAFIHgzdSL2tlFcGtyuu+XIJW3HX2fwQGHcB9+iYpI=", "id"=>"3"}
  User Load (0.1ms)  SELECT  "users".* FROM "users"  WHERE "users"."id" = ? LIMIT 1  [["id", 3]]
   (0.0ms)  begin transaction
  Country Load (0.0ms)  SELECT  "countries".* FROM "countries"  WHERE "countries"."id" = ? LIMIT 1  [["id", 1]]
  Country Load (0.0ms)  SELECT "countries".* FROM "countries" INNER JOIN "user_countries" ON "countries"."id" = "user_countries"."country_id" WHERE "user_countries"."event" = 't' AND "user_countries"."user_id" = ?  [["user_id", 3]]
  SQL (0.1ms)  DELETE FROM "user_countries" WHERE "user_countries"."user_id" = ? AND "user_countries"."country_id" = 2  [["user_id", 3]]
  SQL (0.0ms)  INSERT INTO "user_countries" ("country_id", "event", "user_id") VALUES (?, ?, ?)  [["country_id", 1], ["event", "t"], ["user_id", 3]]
   (20.9ms)  commit transaction
Completed 204 No Content in 28ms (ActiveRecord: 21.3ms)

正如你所看到的似乎它插入合适的内容：（？，？，？） INSERT INTOuser_countries（COUNTRY_ID，事件，USER_ID）VALUES [ COUNTRY_ID，1]，[事件，T]，[user_ID的，3] 但是我得到的已完成204无内容只是在那之后。我不明白，当我刷新页面输入是空的。任何建议？

As you can see it seems that it insert the right content: INSERT INTO "user_countries" ("country_id", "event", "user_id") VALUES (?, ?, ?) [["country_id", 1], ["event", "t"], ["user_id", 3]] However I get the Completed 204 No Content just after that. I don't understand when I refresh the page the input is empty. Any suggestion ?

更新2：

我检查的控制台和它的作品，我可以添加event_countries给用户。然而，它不会显示在用户的event_countries当我刷新页面，我想这是因为我使用了event_country_ids对象。

I checked in the console and it works, I can add event_countries to a user. However it doesn't display the user's event_countries when I refresh the page, I guess that's because I'm using the event_country_ids object.

推荐答案

我觉得下面的code应该工作：

I think the following code should work:

<%= best_in_place @user, :event_country_ids, as: :select, 
  collection: Country.all.each_with_object({}) { |i, memo| memo[i.id] = i.name }, 
  place_holder: "click here to edit",
  html_attrs: { multiple: true } %>

假设你希望用户能够将多个 event_countries 。

参考

• <一个href="http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html#method-i-has_many" rel="nofollow">http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html#method-i-has_many,特别是通过的has_many 创建的 collection_singular_ids = 方法。
• https://github.com/bernat/best_in_place#select ，的结构收集需要一个哈希值。对于每个键=>值对的，关键是什么提交的形式和价值是什么显示给用户。
• http://ruby-doc.org/核心2.1.5 / Enumerable.html＃方法-I-each_with_object ， each_with_object 是核心Ruby库的一部分。

• http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html#method-i-has_many, specifically the collection_singular_ids= method created by has_many.
• https://github.com/bernat/best_in_place#select, the structure of the collection needs to be a hash. For each key => value pair, the key is what's submitted with the form and the value is what's displayed to the user.
• http://ruby-doc.org/core-2.1.5/Enumerable.html#method-i-each_with_object, each_with_object is a part of the core Ruby library.

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