Question

I have a task model related to activities and i want to get a array/hash with all Tasks and their related activities like this:

<% task_group =[
     ['Task1', {'Activity1' => 1, 'Activity2' => 2}], 
     ['Task2', {'Activity3' => 3, 'Activity4'=> 4}]
    ] %>

I came up with Task.includes(:activities).all.map(&:name) but this only gives me a list with activities and their name.

How can i get a complete list including nested relations?

My model defintion:

class Task < ActiveRecord::Base
  has_many :activities

class Activity < ActiveRecord::Base
  belongs_to :task

Answer 1

you can use:

Task.includes(:activities).all.map{|t| [t.name, t.activities.inject({}){|H, a| H[a.name] = a.id; H}]}

EDIT:

Task.includes(:activities).all.map{|t| [t.name, t.activities.inject({}){|h, a| h[a.name] = a.id; h}]}