Question

I have a Stories with a has_many relationship to chapters
Chapter has_many relationship with pages

I would like to return a list of pages on my Stories object with a method Stories.pages

def pages
  self.chapters.map do |c| c.pages end
end

This is not returning a list of lists
ive resorted to doing this

def pages
  pages =[]
  self.chapters.each do |c|
    c.pages.each do |p|
      pages << p
    end
  end
end

I’m new to ruby, with php and c# background, i know i could do this with an association directly between stories and pages or create custom query (INNER JOIN).

But would like to wrap my head around map, reduce methods a little.

Answer 1

No need to create your own custom method, Rails already provides this as has_many :through associations:

class Story < ActiveRecord::Base
  has_many :chapters
  has_many :pages, :through => :chapters
end