Question

我有2个模型，关联many_to_many。在创建品牌时，我有错误：

Admin :: Brands中的NameError #new 显示/.../app/views/admin/brands/_form.html.slim，其中第3行引发：未初始化的恒定品牌:: BrandCatalog

我做错了什么？

#app/models/category.rb
class Category < ActiveRecord::Base
  has_many :brand_catalogs
  has_many :brands, through: :brand_catalogs
end

#app/models/brand.rb
class Brand < ActiveRecord::Base
  has_many :brand_catalogs
  has_many :categories, through: :brand_catalogs
end

#app/models/brandcatalog.rb
class BrandCatalog < ActiveRecord::Base
    belongs_to :category
    belongs_to :brand
end

迁移

#db/migrate/20151230092013_create_brand_catalogs.rb
class CreateBrandCatalogs < ActiveRecord::Migration
  def change
    create_table :brand_catalogs, id: false do |t|
      t.integer :category_id
      t.integer :brand_id
    end

    add_index :brand_catalogs, [:category_id, :brand_id]
  end
end

品牌控制器

#app/controllers/admin/brands_controller.rb
class Admin::BrandsController < Admin::BaseController
  before_action :require_login
  load_and_authorize_resource
  before_action :load_brand, only: [:edit, :update, :destroy]

  def index
    @brands = Brand.all
  end

  def new
    @brand = Brand.new
  end

  def edit
  end

  def create
    @brand = Brand.create(brand_params)
    if @brand.save
     redirect_to admin_brands_path, notice: 'Brand was successfully created.'
    else
     render :new, notice: 'Something wrong!'
   end

  def update

  end

  def destroy
  end

  private
    def load_brand
      @brand = Brand.find(params[:id])
    end

    def brand_params
      params.require(:brand).permit(:title, {category_ids: []})
    end
end

品牌形式

# views/admin/brands/_form.html.slim
= bootstrap_form_for [:admin, @brand] do |f|
  div class='form-group'
    = f.collection_check_boxes(:category_ids, Category.all, :id, :title)

  div class='form-group'
    = f.text_field :title, class: 'form-control'

  = f.submit 'Save', class: 'btn btn-success'

Answer 1

尝试将#app/models/brandcatalog.rb文件重命名为brand_catalog.rb。模型名称需要具有匹配的文件名，但需要使用下划线而不是camelcase。

例如，名为ThisIsMyModel的模型应将其文件命名为this_is_my_model.rb

Rails4中未初始化的常量many_to_many关联

1 个答案: