Rails 4如何为用户（控制器，视图，模型）注册课程

Question

I am currently trying to build a simple learning app with rails and I am facing problems. When a user signs up to a course i try to make a viewed_course record for them so that I can display all the viewed_course on their profile page.

I can't figure out how to set my different controllers so that it creates the viewed_record when I am on the Course Controller /index.

How can I modify the course/index view so that it creates a new viewed record for the current signed in user.

I am using devise.

class Course
    has_many :lessons
end

class Lesson
  #fields: course_id
  belongs_to :course
end
class User
  has_many :viewed_lessons
  has_many :viewed_courses
end
class ViewedLesson
  #fields: user_id, lesson_id, completed(boolean)  
  belongs_to :user
  belongs_to :lesson
end
class ViewedCourse
  #fields: user_id, course_id, completed(boolean)  
  belongs_to :user
  belongs_to :course  
end

Thank you so much in advance for helping me out!

Answer 1

Something like this should do it, this is in courses controller show action (index action should be the list of all courses, show action should be viewing an individual course):

class CoursesController < ApplicationController
  def index
    @courses = Course.all
  end

  def show
    @course = Course.find(params[:id])
    current_user.viewed_courses.create(course: @course)
  end  
end

One gotcha is that this would create a new viewed course every time they viewed the page, you would need some logic to only add each course once.

Perhaps something like this:

def show
  @course = Course.find(params[:id])
  current_user.viewed_courses.create(course: @course) unless ViewedCourse.exists?(user_id: current_user.id, course_id: @course.id)
end