Question

Below are the models that are relevant to my problem. I am attempting to design a way to display CourseEnrollments along with their steps to a given patient. Here is what I have come up with so far.

INDEX ACTION – /course_enrollments/ –> Display courses user is enrolled in as well as the most recent course overview. This can redirect to most recent course.

SHOW ACTION – /course_enrollments/:id –> Display courses user is enrolled in as well as the most recent course overview

The part I am struggling to figure out is how to display an individual step for a course. Should this be done in the course_steps controller (which is nested inside the courses resource)?

class Course < ActiveRecord::Base
  belongs_to :course_category
  belongs_to :client
  belongs_to :user_created, :foreign_key => :user_created_by, :class_name => "User"
  belongs_to :user_updated, :foreign_key => :user_last_updated_by, :class_name => "User"
  has_many :course_steps, :dependent => :destroy
  has_many :steps, :through => :course_steps
  has_many :course_requests, :dependent => :destroy
  has_many :course_enrollments, :dependent => :destroy
  has_many :patients, :through =>:course_enrollments
end

class CourseStep < ActiveRecord::Base
  belongs_to :step
  belongs_to :course

 validates_uniqueness_of :step_id, :scope => :course_id
end

class Step < ActiveRecord::Base
 belongs_to :step_type
 belongs_to :client
 has_one :step_quiz, :dependent => :destroy
 has_one :step_survey, :dependent => :destroy
 has_one :step_text, :dependent => :destroy
 has_one :step_download, :dependent => :destroy
 has_one :step_video, :dependent => :destroy
 has_one :step_presentation, :dependent => :destroy
 has_many :course_steps, :dependent => :destroy
 has_many :courses, :through => :course_steps
end


class CourseEnrollment < ActiveRecord::Base
  belongs_to :patient
  belongs_to :course
end

class Patient < ActiveRecord::Base
  belongs_to :user, :dependent => :destroy
  has_many :enrollments, :dependent => :destroy
  has_many :clients, :through => :enrollments
  has_many :course_requests, :dependent => :destroy
  has_many :course_enrollments, :dependent => :destroy
  has_many :courses, :through => :course_enrollments
end

Answer 1

The usual approach is to nest these and have a compound sort of path, but how you route these things is often dependent on the level of context involved. For instance, is the display of a course driven by a user to the degree that the path should have the user in it, or is it a case of simply personalizing the course page?

Typically you see things like this:

resources :courses do |course|
  course.resources :enrollments
  course.resources :steps
end

There’s usually a correlation between your has_many relationships and declaring an equivalent resources but not always.

Have a look at the generated routes using rake routes to see what the parameters will be called when passed to your controller, as well as what the expected controller name will be. You can customize the name of the controller by passing in a :controller option to the route.

Typically the last record in the path is passed in as :id whereas the prior ones are named, such as :course_id. This is a somewhat annoying inconsistency, so do be careful to check you’re loading using the correct parameters.