Actionmailer deliver to nested resource

Question

I have the following models,

class Exam 
  has_many :registrations
end

class Registration
  belongs_to: user
  belongs_to: lesson
end

class Lesson
  has_many :exam_registrations
  belongs_to :user
end

class User
  has_many :registrations, :through => lessons
end

I'm trying to set up an automated email whereby whenever an Exam is updated an email is delivered to every User who's registered. I've got action mailer set up and working for other non-nested resources but this particular case has stumped me for the past few days.

mailer.rb

  def inform_exam_venue(user, student, lesson, exam_registration, exam)
    @user = user
    @student = student
    @lesson = lesson
    @exam_registration = exam_registration
    @exam = exam
    mail(:to => "#{student.name} <#{student.email}>", :subject => "Exam registration update")
  end

exams_controller.rb

  def update
    @exam = Exam.find(params[:id])

    @exam_registration = @exam.exam_registrations.find(params[:id])

    @lesson = @exam_registration.lesson
    @user = User.where("id =? ", @exam_registration.user_id).first
    @student = Student.where("id =? ", @exam_registration.student_id).first

    respond_to do |format|
      if @exam.update_attributes(params[:exam])
        Mailer.inform_exam_update(@user, @student, @lesson, @exam_registration, @exam).deliver
        format.html { redirect_to @exam, notice: 'Exam was successfully updated.' }
      else
        format.html { render action: "edit" }
      end
    end
  end

My controller code is obviously wrong, but I cant seem to find any instructions on how to set this up. Please help.

Answer 1

the only thing wrong that I found in your code is that you use in the controller

Mailer.inform_exam_update

instead of

Mailer.inform_exam_venue

So, you need to change _update into _venue