我已成功实现了Ryan Bates railscast＃258 http://railscasts.com/episodes/258-token-
fields中未包含的新艺术家条目的添加

因此，换句话说，用户可以输入艺术家名称，该名称将使用jquery tokinput自动完成。但是，我希望自动完成结果仅显示由该个人用户创建的艺术家姓名。

这有意义吗？一个更好的和更易理解的示例是collection.rb，用户在其中创建帖子并为该帖子所属的类别指定“收藏集”，但他们只能将帖子添加到自己创建的收藏集中。

这是带有artist_tokens作为虚拟属性的帖子形式：

<%= form_for @post, :validate => true, :html => {:multipart => true} do |f| %>
  <%= render 'shared/error_messages', :object => f.object %>
    <div class="field">
      <%= f.label :title, 'Title:' %><br /> 
      <%= f.text_field :title %><br />

      <%= f.label :artist_tokens, "Artists" %><br />
      <%= f.text_field :artist_tokens, "data-pre" => 
       @post.artists.map(&:attributes).to_json %>

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

这将通过在张贴表单上的artist_tokens字段中输入的值来查找艺术家，并且我还添加了选项“添加{params [：q]}”以添加新条目。

class ArtistsController < ApplicationController

  def index
    @artists = Artist.where("name like ?", "%#{params[:q]}%")
    results = @artists.map(&:attributes)
    results << {:name => "Add: #{params[:q]}", :id => "CREATE_#{params[:q]}_END"}

    respond_to do |format|
      format.html
      format.json { render :json => results }
    end
  end

我添加了其他代码以按ID解析“新”条目，然后使用它们创建新的艺术家。然后再次分配artist_id。

post.rb
 def artist_tokens=(ids)
    ids.gsub!(/CREATE_(.+?)_END/) do
      Artist.create!(:name => $1).id
    end
    self.artist_ids = ids.split(",")
  end

除了能够仅通过current_user的条目来缩小json结果的功能之外，其他所有功能都非常有效。我将如何去做呢？我是否需要在表中存储条目创建者的user_id？我怎样才能做到这一点？

编辑：模型的关联

# app/models/user.rb

class User < ActiveRecord::Base
  has_many :posts
  has_many :artists, :through => :posts

end



# app/models/post.rb

class Post < ActiveRecord::Base

  belongs_to :user
  has_many :artisanships
  has_many :artists, :through => :artisanships

end

# all/models/artist.rb

class Artist < ActiveRecord::Base

  has_many :artisanships
  has_many :users, :through => :artisanships
  has_many :posts, :through => :artisanships

end


# app/models/artisanship.rb

class Artisanships < ActiveRecord::Base

  belongs_to :post
  belongs_to :artist
  has_one :user, :through => :post

end

编辑：posts_controller.rb

class PostsController < ApplicationController

  before_filter :authenticate_user!, :only => [:create, :edit, :update, :destroy]
  before_filter :authorized_user, :only => [:destroy, :edit, :update]

  def create
    @user = current_user
    @post = current_user.posts.build(params[:post])
    if @post.save
      flash[:success] = "Post created!"
      redirect_to root_path
    else
       @feed_items = current_user.feed.paginate(:per_page => "10", :page => params[:page])
      render 'pages/home'
    end
  end

  def index
    @posts = Post.paginate(:page => params[:page])
  end

  def show
    @post = Post.find(params[:id])
  end

  def edit
    @post = Post.find(params[:id])
  end

  def update
      @post = Post.find(params[:id])
      respond_to do |format|
        if @post.update_attributes(params[:post])
          format.html { redirect_to(post_path(@post), :notice => 'Post was successfully updated.') }
        else
          format.html { render :action => "edit" }  
        end
      end
    end

  def destroy
    @post.destroy
    redirect_to root_path
  end

  def likers
     @title = "Likers"
     @post = Post.find(params[:id])
     @likers = @post.likers.paginate(:page => params[:page])
     render 'show_likers' 
   end

   def search
     if params[:q]
       query = params[:q]
       @search = Post.search do
         keywords query
       end
       @posts = @search.results
     end
   end


private
  def authorized_user
    @post = Post.find(params[:id])
    redirect_to root_path unless current_user?(@post.user)
  end

编辑：尝试alias_method_chain首先设置帖子的user_id属性。（无法修复NULL db条目）参考：Rails
3：a​​lias_method_chain仍在使用吗？

 def attributes_with_user_id_first=(attributes = {})
    # Make sure not to accidentally blank out the important_attribute when none is passed in
    if attributes.include?(:user_id)
      self.user_id = attributes.delete(:user_id)
    end

    self.attributes_without_user_id_first = attributes
  end
  alias_method_chain :attributes=, :user_id_first