Rails 4表单:has_many通过:复选框

Question

原始问题

两个资源:users和animals. 创建用户时,客户端选中复选框以说明他们有多少动物.

提交用户表单时,它不仅应创建新user记录,还应在animal_users富连接表中创建一组记录,以表示客户端选择的每个复选框.

我认为的问题是我没有为表单中的复选框部分正确指定内容.我查看了checkbox_tag API,表单上的Rails指南以及许多网站和stackOverflow帖子.

在此先感谢,代码如下:

原始代码(答案代码进一步向下):

楷模:

#models/user.rb
class User < ActiveRecord::Base
  has_many :animals, through: :animal_users
  has_many :animal_users
  accepts_nested_attributes_for :animal_users, allow_destroy: true
end

#models/animal.rb
class Animal < ActiveRecord::Base
  has_many :users, through: :animal_users
  has_many :animal_users
end

#models/animal_user.rb
class AnimalUser < ActiveRecord::Base
  belongs_to :animal
  belongs_to :user
end

该user表格:

#views/users/_form.html.erb
    <%= form_for(@user) do |f| %>
  <div class="field">
    <%= f.label :name %><br>
    <%= f.text_field :name %>
  </div>

  <div>
    <% Animal.all.each do |animal| %>
    <label>
        <%= check_box_tag "user[animal_ids][]", animal.id, f.object.animals.include?(animal) %>
        <%= animal.animal_name %>
    <% end %>
  </div>

  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

内部强烈的谴责 users_controller.rb

def user_params
      params.require(:user).permit(:name, animal_users_attributes: [:_destroy, :id, :user_id, :animal_id])
end

---

在这里回答代码:

楷模:

#models/user.rb
class User < ActiveRecord::Base
  has_many :animals, through: :animal_users
  has_many :animal_users
end

#models/animal.rb
class Animal < ActiveRecord::Base
  has_many :users, through: :animal_users
  has_many :animal_users
end

#models/animal_user.rb
class AnimalUser < ActiveRecord::Base
  belongs_to :animal
  belongs_to :user
end

该user表格:

#views/users/_form.html.erb
<%= form_for(@user) do |f| %>
  <div class="field">
    <%= f.label :name %><br>
    <%= f.text_field :name %>
  </div>

  # Checkbox part of the form that now works!
    <div>
      <% Animal.all.each do |animal| %>
        <%= check_box_tag "user[animal_ids][]", animal.id, f.object.animals.include?(animal) %>
        <%= animal.animal_name %>
      <% end %>
    </div>

  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

内部强烈的谴责 users_controller.rb

  def user_params
    params.require(:user).permit(:name, animal_ids: [])
  end

而且为了完整起见,这是在表单提交时传递到服务器的内容:

Parameters: {"utf8"=>"?", "authenticity_token"=>"xyz=", "user"=>{"name"=>"Neil", "animal_ids"=>["1", "3"]}, "commit"=>"Create User"}
 Animal Load (0.2ms)  SELECT "animals".* FROM "animals"  WHERE "animals"."id" IN (1, 3)
  (0.1ms)  begin transaction
 SQL (0.2ms)  INSERT INTO "users" ("created_at", "name", "updated_at") VALUES (?, ?, ?)  [["created_at", "2015-03-26 15:29:00.478767"], ["name", "Neil"], ["updated_at", "2015-03-26 15:29:00.478767"]]
 SQL (0.1ms)  INSERT INTO "animal_users" ("animal_id", "created_at", "updated_at") VALUES (?, ?, ?)  [["animal_id", 1], ["created_at", "2015-03-26 15:29:00.479833"], ["updated_at", "2015-03-26 15:29:00.479833"]]
 SQL (0.0ms)  INSERT INTO "animal_users" ("animal_id", "created_at", "updated_at") VALUES (?, ?, ?)  [["animal_id", 3], ["created_at", "2015-03-26 15:29:00.480644"], ["updated_at", "2015-03-26 15:29:00.480644"]]
 SQL (0.1ms)  UPDATE "animal_users" SET "updated_at" = ?, "user_id" = ? WHERE "animal_users"."id" = 6  [["updated_at", "2015-03-26 15:29:00.481362"], ["user_id", 8]]
 SQL (0.1ms)  UPDATE "animal_users" SET "updated_at" = ?, "user_id" = ? WHERE "animal_users"."id" = 7  [["updated_at", "2015-03-26 15:29:00.482062"], ["user_id", 8]]
  (2.4ms)  commit transaction

Answer 1

<% Animal.all.each do |animal| %>
   <label>
      <%= check_box_tag "user[animal_ids][]", animal.id, f.object.animals.include?(animal) %>
      <%= animal.name %>
   </label>
<% end %>

并且你必须在你的控制器参数上接受带有一组id的哈希,比如

{  animal_ids: [] }

也许阅读这个可以帮助:http: //millarian.com/programming/ruby-on-rails/quick-tip-has_many-through-checkboxes/

Answer 2

collection_check_boxes是一个更好的选择:

<%= f.collection_check_boxes(:animal_ids, Animal.all, :id, :name) do |animal| %>
  <%= animal.label { animal.check_box } %>
<% end %>