Question

我有以下型号：RECIPE，TAG和TAGGING（连接表）

recipe.rb

has_many :taggings
has_many :tags, through: :taggings
accepts_nested_attributes_for :taggings

tag.rb

has_many :taggings
has_many :recipes, through: :taggings

scope :diet, -> { where(type_id: 1).to_a }
scope :category, -> { where(type_id: 2).to_a }
scope :festivity, -> { where(type_id: 3).to_a }
scope :daily, -> { where(type_id: 4).to_a }

到目前为止一切正常。但是，在我的TAGS表中，我有一个名为“type_id”的字段，它带给我一种我的标签分类。所以我创造了一些“范围”来区分彼此。

tagging.rb

belongs_to :recipe
belongs_to :tag, :counter_cache => :recipes_count

recipes_controller.rb

def new
    @recipe = Recipe.new
    @recipe.tags.build
    @recipe.taggings.build(:recipe => @recipe)
end

def edit
end

我的表格

= f.fields_for :taggings, @recipe.taggings.build do |builder| 
    = builder.collection_select :tag_id, Tag.diet, :id, :name

= f.fields_for :taggings, @recipe.taggings.build do |builder| 
    = builder.collection_select :tag_id, Tag.category, :id, :name

= f.fields_for :taggings, @recipe.taggings.build do |builder| 
    = builder.collection_select :tag_id, Tag.festivity, :id, :name

= f.fields_for :taggings, @recipe.taggings.build do |builder| 
    = builder.collection_select :tag_id, Tag.daily, :id, :name

当我创建新的RECIPE时，标签通常会添加到连接表（标签）中。但是当我编辑collection_select时，帮助器没有标记为“选中”该项目。

如何构建包含多个范围的collection_select？

如何为EDIT / UPDATE操作构建collection_select？

还有其他更好的方法吗？

Answer 1

尝试

= f.fields_for :taggings, @recipe.taggings do |builder|

而不是

= f.fields_for :taggings, @recipe.taggings.build do |builder|

因为您每次都返回新的标记，而不是重新使用以前创建的标记。

Answer 2

它对我有用：

= f.fields_for :taggings, @recipe.taggings.order("id").first do |diet|
    = diet.collection_select :tag_id, Tag.diet, :id, :name

= f.fields_for :taggings, @recipe.taggings.order("id").second do |category| 
    = category.collection_select :tag_id, Tag.category, :id, :name

= f.fields_for :taggings, @recipe.taggings.order("id").third do |festivity| 
    = festivity.collection_select :tag_id, Tag.festivity, :id, :name

= f.fields_for :taggings, @recipe.taggings.order("id").fourth do |daily| 
    = daily.collection_select :tag_id, Tag.daily, :id, :name

使用has-many-through关联编辑/更新collection_select

2 个答案: