Question

I have a User model, and a Goal model. The Goal model has a name, and a type column, which has the following three records right now.

name           | type
------------------------
Read Novels    | Reading
Read Newspaper | Reading
Write Reviews  | Writing

Now I want to provide each user, an interface to fill in the number of hours they spend on this activity every month (hours_per_month), and the number of different days they do it (days_per_month).

Ideally, I’d want to work with the data like

current_user = User.find(params[:id])

current_user.goals.each do |goal|
  puts goal.name
  puts goal.type
  puts goal.hours_per_month
  puts goal.days_per_month
end

How should I create this new table/model, that joins the Goals to User, and have access to the static Goal attributes, and the user filled values, like the code sample above?

Answer 1

You could create an Activity model and give it a table definition like:

activities:

• user_id
• goal_id
• hours_per_month
• days_per_month

Then add to:

User
  has_many :activities
  has_many :goals, :through => :activity

Goal
  has_many :activities
  has_many :users, :through => :activity

Activity
  belongs_to :user
  belongs_to :goal

You can use a generator to do most of the work iirc.