Activeadmin formtastic动态选择

我想通过Activeadmin的formtastic做一个动态选择选项，如下所示：

form do |f| f.inputs "Exam Registration Details" do f.input :user_id, :as => :select, :collection => User.where(:admin => 'false') #selects user from list. WORKING f.input :student_id, :as => :select, :collection => Student.joins(lessons: :user) #collection of students will change to students who have lessons with chosen user. NOT WORKING, returns all students who have lessons. f.input :lesson_id, :as => :select, :collection => Lesson.joins(:student, :user) #collection of lessons will change to reflect lessons connected by chosen user and student. NOT WORKING, returns all lessons. end f.buttons end 

我的业余代码显然不能像我预期的那样工作。 我应该做些什么改变？

我有4个型号如下：

 class Student < ActiveRecord::Base has_many :lessons has_many :users, through: :lessons has_many :exam_registrations, through: :lessons class Lesson < ActiveRecord::Base belongs_to :user belongs_to :student belongs_to :exam_registration class User < ActiveRecord::Base has_many :lessons has_many :students, through: :lessons has_many :exam_registrations, through: :lessons class ExamRegistration < ActiveRecord::Base has_many :lessons has_many :users, through: :lessons has_many :students, through: :lessons 

Answer 1

解决了

对于其他遇到同样问题的人，请看看这个railscast

这是我如何在activeadmin中实现多个动态选择菜单：

配置/初始化/ active_admin.rb

  config.register_javascript 'exam_registrations.js.coffee' 

应用程序/管理/ exam_registrations.rb

  form do |f| f.inputs "Exam Registration Details" do f.input :user_id, :label => 'Teacher', :as => :select, :collection => User.where(:admin => 'false', :active => true).order(:name), :include_blank => true f.input :student_id, :hint => 'Students grouped by teacher names', :as => :select, :collection => option_groups_from_collection_for_select(User.where(:admin => false, :active => true).order(:name), :students, :name, :id, :name) f.input :lesson_id, :hint => 'Lessons grouped by student names', :as => :select, :collection => option_groups_from_collection_for_select(Student.where(:active => true).order(:name), :lessons, :name, :id, :name) end f.buttons end 

应用程序/资产/ JavaScript的/ exam_registrations.js.coffee

 #first menu jQuery -> $('#exam_registration_student_id').parent().hide() students = $('#exam_registration_student_id').html() $('#exam_registration_user_id').change -> user = $('#exam_registration_user_id :selected').text() escaped_user = user.replace(/([ #;&,.+*~\':"!^$[\]()=>|\/@])/g, '\\$1') options = $(students).filter("optgroup[label='#{escaped_user}']").html() if options $('#exam_registration_student_id').html(options) $('#exam_registration_student_id').parent().show() else $('#exam_registration_student_id').empty() $('#exam_registration_lesson_id').empty() # second menu $('#exam_registration_lesson_id').parent().hide() lessons = $('#exam_registration_lesson_id').html() $('#exam_registration_student_id').click -> student = $('#exam_registration_student_id :selected').text() escaped_student = student.replace(/([ #;&,.+*~\':"!^$[\]()=>|\/@])/g, '\\$1') options = $(lessons).filter("optgroup[label='#{escaped_student}']").html() if options $('#exam_registration_lesson_id').html(options) $('#exam_registration_lesson_id').parent().show() else $('#exam_registration_lesson_id').empty() 

重启服务器，菜单工作！