Model Relationships

Question

So I am building this ruby on rails webapp. I have two models: Courses and lessons. Courses has many lessons and lesson belongs to course. I have the forms running just fine but what i want to do is pass the :course_id to the lesson form to be able to keep track of what course the lesson belongs to. ( I have included a course_id value in the lesson table.

Basically, my question is how can i pass the :id of the course onto the lesson form?

Answer 1

Why not just assign the new lesson the course id?

Instead of doing

@lesson = Lesson.new

do

@lesson = Course.find(params[:course_id]).lessons.new

or something of that sort.

Or (better):

@lesson = Course.find(params[:course_id]).lessons.build

Answer 2

A hidden field?

Not sure what you want to do with this course_id in the form, but if it's just to pass it back on submit, look into Nested Resources