representable_example.rb

require 'representable/json'
require 'representable/json/collection'
 
# representers
module StudentProgressRepresenter
  include Representable::JSON
 
  property :id
  collection :precinct_progresses#, extend: PrecinctProgressRepresenter, class: PrecinctProgress
end
 
module PrecinctProgressesRepresenter
  include Representable::JSON::Collection
 
  items extend: PrecinctProgressRepresenter
end
 
module PrecinctProgressRepresenter
  include Representable::JSON
 
  property :precinct
  property :maximum_lesson
end

PrecinctProgress = Class.new(Struct.new(:precinct, :maximum_lesson))
class StudentProgress
  attr_accessor :id, :precinct_progresses

  def initialize(id)
    @id = id
  end

  def id
    @id
  end

  def precinct_progresses
    [
      PrecinctProgress.new('my_lessons', 1),
      PrecinctProgress.new('my_lessons', 2),
      PrecinctProgress.new('my_lessons', 3),
    ]
  end
end

student_progress = StudentProgress.new(1)
StudentProgressRepresenter.prepare(student_progress).to_json
from_json = "{\"5612776\":[{\"precinct_progress\":{\"precinct\":\"my_lessons\",\"maximum_lesson\":1}},{\"precinct_progress\":{\"precinct\":\"english_skills_spelling\",\"maximum_lesson\":22}}],\"5612778\":[{\"precinct_progress\":{\"precinct\":\"my_lessons\",\"maximum_lesson\":45}},{\"precinct_progress\":{\"precinct\":\"english_skills_spelling\",\"maximum_lesson\":122}}],\"5612775\":[{\"precinct_progress\":{\"precinct\":\"my_lessons\",\"maximum_lesson\":1}},{\"precinct_progress\":{\"precinct\":\"english_skills_spelling\",\"maximum_lesson\":1}}],\"5612777\":[{\"precinct_progress\":{\"precinct\":\"my_lessons\",\"maximum_lesson\":1}},{\"precinct_progress\":{\"precinct\":\"english_skills_spelling\",\"maximum_lesson\":1}}],\"4766964\":[{\"precinct_progress\":{\"precinct\":\"my_lessons\",\"maximum_lesson\":1}},{\"precinct_progress\":{\"precinct\":\"english_skills_spelling\",\"maximum_lesson\":1}}]}"
StudentProgress.new(1).extend(StudentProgressRepresenter).from_json(from_json)

So if we replaced precinct_progresses with the hash that's in the spec for the presenter: i.e.

   {"5612776" =>
   [{ "precinct_progress" => { "precinct" => "my_lessons", "maximum_lesson" => 1 } },
    { "precinct_progress" => { "precinct" => "english_skills_spelling", "maximum_lesson" => 22 } }],
   "5612778" =>
   [{ "precinct_progress" => { "precinct" => "my_lessons", "maximum_lesson" => 45 } },
    { "precinct_progress" => { "precinct" => "english_skills_spelling", "maximum_lesson" => 122 } }],
   "5612775" =>
   [{ "precinct_progress" => { "precinct" => "my_lessons", "maximum_lesson" => 1 } },
    { "precinct_progress" => { "precinct" => "english_skills_spelling", "maximum_lesson" => 1 } }],
   "5612777" =>
   [{ "precinct_progress" => { "precinct" => "my_lessons", "maximum_lesson" => 1 } },
    { "precinct_progress" => { "precinct" => "english_skills_spelling", "maximum_lesson" => 1 } }],
   "4766964" =>
   [{ "precinct_progress" => { "precinct" => "my_lessons", "maximum_lesson" => 1 } },
    { "precinct_progress" => { "precinct" => "english_skills_spelling", "maximum_lesson" => 1 } }] }

then does StudentProgress (edit - and PrecinctProgress) need to contain the logic of parsing this for a student or will this be handled somewhere else in PrecinctProgressRepresenter?