在视图中呈现现有类别，rails

Question

如何在我的视图中呈现现有类别的列表？

我的类别表有一个:name 列。

产品视图

 = f.select :category_name, Category.all.map{|s| [s.name]}

类别.rb

class Category < ActiveRecord::Base
    has_many :categoricals
    validates :name, uniqueness: { case_sensitive: false }, presence: true
    acts_as_tree order: "name"
end

产品.rb

class Product < ActiveRecord::Base
   include ActionView::Helpers
   include Categorizable
end

更新：

完整的产品形式

= simple_form_for @product, html: { multipart: true } do |f|
        = f.input :title, placeholder: "Product Name", required: false, label: false
        = f.input :description, placeholder: "Description", required: false, label: false
        = f.select :category_name, Category.all.map{|s| s.name}

        = f.input :image, label: false


    = f.button :submit, class: "button"

更新#2： 产品控制器

def update
    if @product.update(product_params)
        redirect_to @product, notice: "Your Product was successfully updated!"
    else
        render 'edit'
    end
end

分类模型

class Categorical < ActiveRecord::Base
belongs_to :category
belongs_to :categorizable, polymorphic: true

validates_presence_of :category, :categorizable
end

分类模块

    module Categorizable 
  extend ActiveSupport::Concern

  included do
    has_many :categoricals, as: :categorizable
    has_many :categories, through: :categoricals
  end

  def add_to_category(category)
    self.categoricals.create(category: category)
  end

  def remove_from_category(category)
    self.categoricals.find_by(category: category).maybe.destroy
  end


 module ClassMethods
  end
end

Answer 1

我不明白为什么人们不使用collection_select 而不是select：

= f.collection_select :category_id, Category.all, :id, :name

---

看来真正的问题在于你们的关系：

#app/models/category.rb
class Category < ActiveRecord::Base
   has_many :products
end

#app/models/product.rb
class Product < ActiveRecord::Base
   belongs_to :category #-> requires category_id column in products table
end

这将允许您引用:category_id，如下所示：

= simple_form_for @product, html: { multipart: true } do |f|
    = f.input :title, placeholder: "Product Name", required: false, label: false
    = f.input :description, placeholder: "Description", required: false, label: false
    = f.collection_select :category_id, Category.all, :id, :name
    = f.input :image, label: false

    = f.button :submit, class: "button"

Answer 2

试试：

= f.select :category_name, Category.all.map{|s| s.name}

为了完成这项工作，您的category_name 表中必须存在category_name 列。