首先让我先说这也可能是一个建模问题,我对模型建议持开放态度.
使用案例：
我有一个表单,我需要允许用户选择他们的帖子类别的复选框.如果没有适合其帖子检查的类别,则其他类别将显示用户添加自定义类别的文本字段.这应该用于创建和更新嵌套模块
数据库建模
class CreateCategories < ActiveRecord::Migration
def change
create_table :categories do |t|
t.string :name,null: false
t.timestamps null: false
end
reversible do |dir|
dir.up {
Category.create(name: 'Hats')
Category.create(name: 'Shirts')
Category.create(name: 'Pants')
Category.create(name: 'Shoes')
Category.create(name: 'Other')
}
end
create_table :categorizations,id: false do |t|
t.belongs_to :post,index: true,null: false
t.belongs_to :category,null: false
t.string :value
end
end
end
应用模型
class Post < ActiveRecord::Base has_many :categorizations accepts_nested_attributes_for :categorizations,allow_destroy: true has_many :categories,through: :categorizations accepts_nested_attributes_for :categories end class Category < ActiveRecord::Base has_many :posts end
控制器：
def update
if @post.update(post_params)
flash.now[:success] = 'success'
else
flash.now[:alert] = @post.errors.full_messages.to_sentence
end
render :edit
end
private
def set_post
@post = Post.find(params[:id])
(Category.all - @post.categories).each do |category|
@post.categorizations.build(category: category)
end
@post.categorizations.to_a.sort_by! {|x| x.category.id }
end
def post_params
params.require(:post).permit(:name,:description,categorizations_attributes: [ :category_id,:value,:_destroy],)
end
视图：
= f.fields_for :categorizations do |ff|
= ff.check_Box :_destroy,{ checked: ff.object.persisted? },'0','1'
= ff.label :_destroy,ff.object.category.name
= ff.hidden_field :category_id
= ff.text_field :value if ff.object.category.other?
解决方法
我更喜欢这样的东西：
楷模
post.rb
class Post < ActiveRecord::Base has_many :categorizations has_many :categories,through: :categorizations accepts_nested_attributes_for :categorizations,allow_destroy: true accepts_nested_attributes_for :categories end
category.rb
class Category < ActiveRecord::Base has_many :categorizations has_many :posts,through: :categorizations end
调节器
...
def update
if @post.update(post_params)
flash.now[:success] = 'success'
else
flash.now[:alert] = @post.errors.full_messages.to_sentence
end
render :edit
end
private
def set_post
@post = Post.find(params[:id])
end
def post_params
params.require(:post).permit(:name,category_ids: [])
end
...
查看
我总是喜欢普通的.erb所以,
在simple_form的帮助下.
<%= simple_form_for(@post) do |f| %>
<%= f.error_notification %>
<div class="form-inputs">
<%= f.input :content -%>
...
</div>
<div class="form-inputs">
<%= f.association :categories,as: :check_Boxes -%>
</div>
<div class="form-actions">
<%= f.button :submit %>
</div>
<% end %>
您可以通过这种方式检查/取消选中状态并轻松干净地销毁.
另外,你可以添加
<%= f.simple_fields_for :category do |category_fields| %> <%= category_fields.input :name -%> <% end %>
获取关联的嵌套字段,但不要忘记在执行此操作时将相关的参数添加到strong_params.
... def post_params params.require(:post).permit(:name,category_attributes: [:name]) end ....