Rails has_many：通过collection_select表单帮助程序

我在创建一个可以保存我的has_many的表单时遇到问题：通过关联。 我通过发布json成功保存了，但这些表单对我来说还不行。 由表单提交创建的请求参数将无法解决。 任何指导我解决方案的帮助都会帮助我不再浪费时间。 先谢谢你。

编辑 – 添加了forms_for的尝试和创建的params json，它在底部不起作用 –

Json发布请求有效的参数：

{ "author": { "name": "Author Name", "post_authors_attributes": [ {"post_id":"1"}, {"post_id":"2"}, {"post_id":"3"} ] } } 

Rails形成了无法保存的参数。

 { "author": { "name": "assd", "post_authors_attributes": [ "", "2", "3" ] } } 

……以及相关的代码示例……

作者模型

 class Author  :post_authors accepts_nested_attributes_for :post_authors end 

发布模型 （ 目前只在作者上工作有很多post，而不是相反 ）

 class Post < ActiveRecord::Base end 

PostAuthor模型

 class PostAuthor < ActiveRecord::Base belongs_to :post belongs_to :author end 

作者控制器新建/创建动作

  # GET /authors/new def new @author = Author.new @author.post_authors.build end # POST /authors # POST /authors.json def create @author = Author.new(params) respond_to do |format| if @author.save format.html { redirect_to @author, notice: 'Author was successfully created.' } format.json { render :show, status: :created, location: @author } else format.html { render :new } format.json { render json: @author.errors, status: :unprocessable_entity } end end end 

作者/ _form.html.erb

   
 
 prohibited this author from being saved:
 
  
  
 
  
 
  
  @author.posts.map(&:id)}, {:multiple => true}) %> 
  
  

架构

 ActiveRecord::Schema.define(version: 20150120190715) do create_table "authors", force: :cascade do |t| t.string "name" t.datetime "created_at", null: false t.datetime "updated_at", null: false end create_table "post_authors", force: :cascade do |t| t.integer "post_id" t.integer "author_id" t.datetime "created_at", null: false t.datetime "updated_at", null: false end create_table "posts", force: :cascade do |t| t.string "title" t.datetime "created_at", null: false t.datetime "updated_at", null: false end end 

编辑 – 添加详细信息 –只是为了尽职尽责，我也尝试使用fields_for，但它产生更加混乱的json，不保存到数据库。 我不知道“0”键来自哪里。 我坚持这一点，任何帮助将非常感激。

fields_for

  
  
  @author.posts.map(&:id)}, {:multiple => true}) %>   

制作参数to_json

 { "author": { "name": "test", "post_authors_attributes": { "0": { "post_id": [ "", "1", "2", "3" ] } } } } 

Answer 1

对于遇到同类问题的人，我终于设法使用以下collection_select：

  <%= f.collection_select(:feature_ids, Feature.all, :id, :name, {include_blank: false, :include_hidden => false, :selected => @property.features.map(&:id)}, {:multiple => true}) %> 

Answer 2

authors/_form.html.erb ：

 <%= fields_for(@author_book) do |ab| %> 
 <%= ab.label "All Books" %>
 <%= collection_select(:books, :id, @all_books, :id, :name, {:selected => @author.books.map(&:id)}, {multiple: true}) %> 
 <% end %> 

authors_controller.rb ：

 class AuthorsController < ApplicationController before_action :set_author, only: [:show, :edit, :update, :destroy] # GET /authors # GET /authors.json def index @authors = Author.all end # GET /authors/1 # GET /authors/1.json def show end # GET /authors/new def new @author = Author.new get_books respond_to do |format| format.html format.json { render json: @author } end end # GET /authors/1/edit def edit get_books end # POST /authors # POST /authors.json def create @author = Author.new(author_params) params[:books][:id].each do |book| if !book.empty? @author.authorbooks.build(:book_id => book) end end #binding.pry respond_to do |format| if @author.save format.html { redirect_to @author, notice: 'Author was successfully created.' } format.json { render :show, status: :created, location: @author } else format.html { render :new } format.json { render json: @author.errors, status: :unprocessable_entity } end end end # PATCH/PUT /authors/1 # PATCH/PUT /authors/1.json def update #binding.pry respond_to do |format| if @author.update(author_params) @author.books = [] params[:books][:id].each do |book| if !book.empty? @author.books << Book.find(book) end end format.html { redirect_to @author, notice: 'Author was successfully updated.' } format.json { render :show, status: :ok, location: @author } else format.html { render :edit } format.json { render json: @author.errors, status: :unprocessable_entity } end end end # DELETE /authors/1 # DELETE /authors/1.json def destroy @author.destroy respond_to do |format| format.html { redirect_to authors_url, notice: 'Author was successfully destroyed.' } format.json { head :no_content } end end private # Use callbacks to share common setup or constraints between actions. def set_author @author = Author.find(params[:id]) end # Never trust parameters from the scary internet, only allow the white list through. def author_params params.require(:author).permit(:name,:authorbooks_attributes => [:id,:book_ids => []]) end def get_books @all_books = Book.all @author_book = @author.authorbooks.build end # def create_params # params.require(:authorbooks).permit(:author_id,book_id: []) # end end