Ruby on rails rails中通过表的多对多关系的嵌套表单不保存属性

我有一个Blog模型和一个标记模型，它们通过表（model:BlogTag）Blog_标记具有多对多关联。我已经在博客中实现了一个嵌套表单来添加标签

我在参数中得到了标签和属性。但是当我保存blog对象时，它确实会将tag对象保存到blog中，但是它确实会通过name=nil保存它

博客模式

下面可以看到，在table tag的insert命令中，名称字段并没有得到值，因此变为nil

服务器日志

（1.2ms）开始
SQL（0.9ms）在“blogs”（“blog”、“title”、“slugurl”、“created_u at”、“updated_at”）值（$1、$2、$3、$4、$5）中插入返回“id”[[“blog”、“adsfafsfas
\r\n”]、[“title”、“test 11”]、[“slugurl”、“asdff”]、[“created_at”、“2017-07-19 08:31:32.677338”]、[“updated_at”、“2017-07-19 08:31:32.677338”]
SQL（0.6ms）插入到“标记”（“创建时间”，“更新时间”）值（$1，$2）中，返回“id”[[“创建时间”，“2017-07-19 08:31:32.684302”]，[“更新时间”，“2017-07-19 08:31:32.684302”]]
SQL（1.1ms）插入“博客标签”（“博客id”、“标签id”、“创建时间”、“更新时间”）值（$1，$2，$3，$4）返回“id”[[“博客id”，20]，“标签id”，18]，“创建时间”，“2017-07-19 08:31:32.706957”]，[“更新时间”，“2017-07-19 08:31:32.706957”]
（8.3ms）提交
重定向到http://localhost:3000/blogs
在33792ms内完成302次（ActiveRecord:15.8ms）

Params

{“utf8”=>“✓", "真实性令牌“=>”+1ZLYPJkQCVOkOSt6dmy9z12XgOMP+OYu0XOOzKUlv+xldd5fkB2RR/oA7qpn53YE+82FDJVEO2YLHKPIEWFWVW=”，“blog”=>“{”title“=>“编程语言”，“标记属性”=>{“0”=>{“name”=>[“Python”，“C#”，“.NET”}>，“slugurl”=>“pro lang”，“blog”=>“ASDFASDF afaadf afaadf=>，“提交博客”=>

表格（视图）

禁止保存此博客：

我在参数中得到了标签和属性。但是当我保存博客的时候 对象它确实将标记对象保存到它，但它确实按名称保存它= 零

根据

参数

散列，您正在为

名称

发送多个值，因此需要修改

blog_参数

以接受

名称

的多个值

def blog_params
  params.require(:blog).permit(:blog,
                               :title,
                               :slugurl,
                               tags_attributes: [name: []]
  )
end

---

使用日志中显示的表单和参数哈希更新您的问题，请立即查看。@RaounaqSharma乐于帮助：）将答案标记为已接受：）

class Tag < ActiveRecord::Base
  has_many :blog_tags, dependent: :destroy
  has_many :blogs, through: :blog_tags
end

class BlogTag < ActiveRecord::Base
  belongs_to :blog
  belongs_to :tag
end

  def new
    @blog = Blog.new
    @blog.tags.build
  end

  def create
    @blog = Blog.new(blog_params)
    save_tag_for
    byebug
    respond_to do |format|
      if @blog.save
        format.html { redirect_to blogs_path, notice: 'Blog was successfully created.' }
        format.json { render :index, status: :created, location: @blog}
      else
        format.html { render :new }
        format.json { render json: @blog.errors, status: :unprocessable_entity }
      end
    end
  end

def blog_params
  params.require(:blog).permit(:blog,
                               :title,
                               :slugurl,
                               tags_attributes: [:name]
  )
end

  (1.2ms)  BEGIN
  SQL (0.9ms)  INSERT INTO "blogs" ("blog", "title", "slugurl", "created_at", "updated_at") VALUES ($1, $2, $3, $4, $5) RETURNING "id"  [["blog", "<p>adsfadsfdfas</p>\r\n"], ["title", "test 11"], ["slugurl", "asdfdf"], ["created_at", "2017-07-19 08:31:32.677338"], ["updated_at", "2017-07-19 08:31:32.677338"]]
  SQL (0.6ms)  INSERT INTO "tags" ("created_at", "updated_at") VALUES ($1, $2) RETURNING "id"  [["created_at", "2017-07-19 08:31:32.684302"], ["updated_at", "2017-07-19 08:31:32.684302"]]
  SQL (1.1ms)  INSERT INTO "blog_tags" ("blog_id", "tag_id", "created_at", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "id"  [["blog_id", 20], ["tag_id", 18], ["created_at", "2017-07-19 08:31:32.706957"], ["updated_at", "2017-07-19 08:31:32.706957"]]
   (8.3ms)  COMMIT
Redirected to http://localhost:3000/blogs
Completed 302 Found in 33792ms (ActiveRecord: 15.8ms)

{"utf8"=>"✓", "authenticity_token"=>"+1ZLYPJkQCVOkOSt6dmy9z12XgOMP+OYu0XOOzKUlv+xldd5fkB2RR/oA7qpn53YE+82FDjVeO2ylHkPIEWfVw==", "blog"=>{"title"=>"Programming Languages", "tags_attributes"=>{"0"=>{"name"=>["Python", "C#", ".NET"]}}, "slugurl"=>"pro-lang", "blog"=>"<p>asdfasdfasdf afaadf</p>\r\n"}, "commit"=>"Submit", "controller"=>"blogs", "action"=>"create"}

<%= form_for(@blog) do |f| %>
  <% if @blog.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@blog.errors.count, "error") %> prohibited this blog from being saved:</h2>

      <ul>
      <% @blog.errors.full_messages.each do |message| %>
        <li><%= message %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

          <div class="row">
            <div class="form-group">
            <%= f.label :title ,class: 'control-label' %><br>
            <%= f.text_field :title ,class: 'form-control' %>

            <div class="help-block with-errors"></div>
            </div>
          </div>

          <div class="row">
            <div class="form-group">
              <%= f.fields_for :tags do |tag_builder| %>
                  <%= tag_builder.label :name, "Tag", class: 'control-label' %><br>
                  <%= tag_builder.select :name, Tag.all.pluck(:name,:name), {}, {multiple: true, class: "selectize" } %>
              <%end%>
              <%#= form.select :category_id, Category.all.pluck(:name,:id), {}, {multiple: true, class: "selectize"} %>
              <div class="help-block with-errors"></div>
            </div>
              </div>
          <div class="row">
            <div class="form-group">
            <%= f.label :slugurl ,class: 'control-label' %><br>
            <%= f.text_field :slugurl ,class: 'form-control' %>

            <div class="help-block with-errors"></div>
            </div>
          </div>


          <div class="row">
            <div class='form-group'>
             <%= f.label :blog ,class:'control-label'%><br>
             <%= f.cktext_area :blog, rows: 10,class:'form-control' %>
            <div class="help-block with-errors"></div>
            </div>
          </div>

              <div class="form-actions mg-t-lg">
                <div class="row">
                  <div class="col-sm-7 col-sm-offset-5">
                    <div class="text-center-xs">
                      <input type="submit" name="commit" value="Submit" class="btn btn-contrast" />
                    </div>
                    </div>
                </div>
                </div>

<% end %>

def blog_params
  params.require(:blog).permit(:blog,
                               :title,
                               :slugurl,
                               tags_attributes: [name: []]
  )
end