找不到關聯的名稱 - 嵌套窗體軌跡4

Question

我在使用嵌套窗體的has_many/has_many關係有以下問題。

我有文章，這可以有許多單位（公斤，袋等）。通過我的表單，我需要記錄這些數據。

所以我決定用嵌套形式關係的has_many但我有一個錯誤：ArgumentError (No association found for name 'article_unit_of_measurements'. Has it been defined yet?)

這是我的班級代碼：

class Article < ActiveRecord::Base 
    has_many :unit_of_measurements, :through => :article_unit_of_measurements 
    accepts_nested_attributes_for :article_unit_of_measurements 
end 

class ArticleUnitOfMeasurement < ActiveRecord::Base 
    belongs_to :article 
    belongs_to :unit_of_measurement 

    accepts_nested_attributes_for :unit_of_measurement 
end 


class UnitOfMeasurement < ActiveRecord::Base 
    has_many :articles, :through => :article_unit_of_measurements 
end 

在我的形式使用jQuery插件select2.js將我的選擇單位顯示爲標籤。

= simple_form_for([:shop, @article], html: {class: 'form-horizontal' }) do |f| 
    .col-md-10 
    = f.input :name, placeholder: "Name", :input_html => {:class => 'form-control'}, label: false 
    %label.col-md-2.control-label{for: "unit_of_measurement_id"} Unidad de medida 
    .col-md-10 
     %select#unit-select-measure.select2{:name =>"article[article_unit_of_measurements_attributes][#{Time.now.to_s}][unit_of_measurement_id]", :style => "width:100%;;padding: 0;border: none;", :multiple => true} 
     - @unitOfMeasurement.each do |unit| 
      %option{:value => "#{unit.id}"} 
      = unit.name 
    %button.btn.btn-primary{type: "submit"} Guardar 
:javascript 
    $('#unit-select-measure').select2(); 

這是我的控制器：

class Shop::ArticlesController < ApplicationController 
def new 
    @article = Article.new 
    @unitOfMeasurement = UnitOfMeasurement.all 
    render layout: false 
    end 

    def create 
    article = Article.new(article_parameters) 
    if article.save 
     flash[:notice] = "Lorem ipsum dolor sit amet." 
     redirect_to :action => :index 
    else 
     flash[:error] = "Lorem ipsum dolor sit amet." 
     redirect_to :action => :index 
    end 
    end 

    private 
    def article_parameters 
    params.require(:article).permit(:name, article_unit_of_measurements_attributes: [:id, :article_id, :unit_of_measurement_id]) 
    end 
end 

Pd積：數據單位已填充

Answer 1

更換

class Article < ActiveRecord::Base 
    has_many :unit_of_measurements, :through => :article_unit_of_measurements 
    accepts_nested_attributes_for :article_unit_of_measurements 
end 

與

class Article < ActiveRecord::Base 
    has_many :article_unit_of_measurements ## Added association 
    has_many :unit_of_measurements, :through => :article_unit_of_measurements 
    accepts_nested_attributes_for :article_unit_of_measurements 
end 

您錯過了has_many association與article_unit_of_measurements。

因此，錯誤ArgumentError (No association found for name 'article_unit_of_measurements'