collection_select内容未显示

Question

我目前正在尝试通过 collection_select 表单显示内容标识自己的组织。

问题在于创建新联系人并选择组织后。组织不显示。

到目前为止，我已尝试在网上搜索答案，但没有任何帮助。我也尝试过我能想到的所有问题都是我的代码问题。

以下是模型：

class Contact < ApplicationRecord
has_many :contact_orgs
has_many :organizations, through: :contact_orgs
accepts_nested_attributes_for :organizations
end

class Organization < ApplicationRecord
has_many :contact_orgs
has_many :contacts, through: :contact_orgs
end

class ContactOrg < ApplicationRecord
belongs_to :contact
belongs_to :organization
accepts_nested_attributes_for :organization
end

这是我的 schema.rb ：

create_table "contact_orgs", force: :cascade do |t|
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.integer "contact_id"
t.integer "organization_id"
t.index ["contact_id"], name: "index_contact_orgs_on_contact_id"
t.index ["organization_id"], name: "index_contact_orgs_on_organization_id"
end

create_table "contacts", force: :cascade do |t|
t.string "first_name"
t.string "last_name"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
end

create_table "organizations", force: :cascade do |t|
t.string "name"
t.datetime "created_at", null: false
t.datetime "updated_at", null: false
t.string "industry"
end

这是我的 contact_controller.rb ：

private
def contact_params
params.require(:contact).permit(:first_name, :last_name, 
organizations_attributes: [:name, :industry])
end

def new
@contact = Contact.new
end

def show
@contact = Contact.find(params[:id])
end

def create
@contact = Contact.new(contact_params)
if @contact.save
redirect_to @contact
else
render 'new'
end
end

这是 contact / new.html.erb ：

<%= form_with scope: :contact, url: contact_path, local: true do |form| %>

<p>
<%= form.label :first_name %><br>
<%= form.text_field :first_name %>
</p>

<p>
<%= form.label :last_name %><br>
<%= form.text_field :last_name %>
</p>

<p>
<%= form.label :organization_id, "Organization:" %><br>
<%= form.collection_select :organization_id, Organization.order(:name), :id, :name, {}, {multiple: true} %>
</p>

<p>
<%= form.submit %>
</p>
<% end %>

这是 contact / show.html.erb ：

<p>
<strong>First name:</strong>
<%= @contact.first_name %>
</p>

<p>
<strong>Last Name:</strong>
<%= @contact.last_name %>
</p>
<hr>

<p>
<strong>Organizations:</strong>
<ul>
<% @contact.organizations.each do |organization| %>
<li><%= organization.name %></li>
<% end %>

</ul>
</p>

当我刷新 localhost：3000 / contact / 2 页面时，这是我的 Rails服务器所说的内容。

以下是我的Rails控制台中的内容：

2.4.1 :001 > Contact.find(2).organizations
Contact Load (0.2ms)  SELECT  "contacts".* FROM "contacts" WHERE "contacts"."id" = ? LIMIT ?  [["id", 2], ["LIMIT", 1]]
Organization Load (0.2ms)  SELECT  "organizations".* FROM "organizations" INNER JOIN "contact_orgs" ON "organizations"."id" = "contact_orgs"."organization_id" WHERE "contact_orgs"."contact_id" = ? LIMIT ?  [["contact_id", 2], ["LIMIT", 11]]=> #<ActiveRecord::Associations::CollectionProxy []> 

这是我的 routes.rb 文件：

Rails.application.routes.draw do
get 'welcome/index'

resources :contacts, :organizations

root 'welcome#index'
end

提前谢谢你：）

修改： 通过Rails c命令添加了 Contacts＃Show 方法和 Contact.find（2）.organization 。

添加 routes.rb

Answer 1

由于您正在使用联接表（ContactOrg），因此在创建ContactOrg时，您确实在尝试创建新的Contact记录，而不是将其分配给Organization }，这是你的代码读取的方式。

编辑

虽然我上面的第一个声明仍然有一点点优点（你实际上正在创建一个连接记录），但你绝对可以让rails帮助你，你的原始答案非常接近。这里只有有更新的代码，我试图突出显示更改。

应用/模型/ contact.rb

class Contact < ApplicationRecord
  has_many :contact_orgs
  has_many :organizations, through: :contact_orgs

  accepts_nested_attributes_for :organizations # you were correct here
end

应用/视图/接触/ new.html.erb

<%= form_with model: :contact, local: true do |form| %>
  # use :model here so you can ultimately use this form for both new and edit.
  # The model method will infer the correct path

  ... contact fields here as you have them ...

  <p>
    <%= form.collection_select :organization_ids, Organization.order(:name), :id, :name, {}, {multiple: true} %>
    # the attribute for organization_id should be plural because you're accepting multiple
  <p>

  <p>
    <%= form.submit %>
  </p>
<% end %>

应用/控制器/ contacts_controller.rb

class ContactsController < ApplicationController


  ... new, show, and create as you have them ...

   private # private methods should go after all public methods 

   def contact_params
     params.require(:contact).permit(:first_name, :last_name, organization_ids: [])
     # again, the attribute you're passing in is called organization_ids, and you give it an empty array
   end
end

Answer 2

有两个问题：

1. 您无法将组织保存到合同中。 您可以通过Contact.find（2）.organizations登记we can Auto save form using Ajax function AutoSaveMyForm(spanid) { var dataToPost = $("form").serialize() $.ajax({ type: "POST", url: "/MyController/AutoSaveActionMethod", data: dataToPost, cache: false, success: function(resultdata) { if (resultdata['Code'] == '1') { // show success saved console.log(resultdata['ResultMsg']); if (spanid == "SaveLastStep") { window.location = "/Dashboard/Index"; } $('#' + spanid).html('Save Successfully.'); } else if (resultdata['Code'] == '0') { // show error console.log(resultdata['ResultMsg']); $('#' + spanid).html('Not Saved'); } else { // an error has occured $('#' + spanid).html('Error Generated.'); } } }); } window.setInterval(function() { AutoSaveMyForm('SpanIdToShowResult') }, 60000); // 1 min By using set interval method we can call javascript method which call ajax to save form and pass any span id to get result back 。
2. 我们从不使用私有方法编写新内容和创建。

您的私人方法不应包含任何凝乳。

在 app / controllers / contacts_controller.rb

中

rails c

在 app / views / contact / new.html.erb

中

private

def contact_params
  params.require(:contact).permit(
    :first_name, 
    :last_name, 
    organizations_attributes: [
      :name, 
      :industry
    ]
 )
end

Answer 3

您的contract_controller不会初始化 show.html.erb 中使用的 @contact ，因为没有任何show方法。

尝试添加contact_controller

def show
  @contact = Contact.find(param[:id])
end

PS：当你调用show方法时，一定要传递给contact.id

我希望这对你有所帮助。