how to use an instance of a model in another serializer - ruby-on-rails

Question

I'm stuck here and couldn't find solution to proceed my work,
I have 3 models: plans, days, and meals.
This is my Plan Controller I've managed to get the correct answer in the controller, I want it nested and inside the serializer because I'm using URL helper to retrieve my images URLs, is there a possible way to use the #plan.id inside the DaySerializer?
def meals
#plan = Plan.find(params[:id])
#days = #plan.days
#meals = Meal.where("plan_id = ? ", #plan.id)
render :json => { :plan => #plan, :days => #days,
:meals => #meals }
end
This is my Plan model
class Plan < ApplicationRecord
has_many :days
has_one_attached :image, dependent: :destroy
end
This is my Day model
class Day < ApplicationRecord
has_many :meals
has_many :plans
end
This is my Meal model
class Meal < ApplicationRecord
belongs_to :plan
belongs_to :day
has_one_attached :image, dependent: :destroy
end
I want to show all meals for a specific Plan, to do that I need to use a variable inside the daySerializer but I couldn't find how to do it.
This is my planSerializer
class PlanSerializer < ActiveModel::Serializer
attributes :id, :name, :monthly_price, :plan_days
def plan_days
object.days.map do |day|
DaySerializer.new(day, scope: scope, root: false, event: object)
end
end
end
and this is my DaySerializer which I need to use the instance of the plan inside
class DaySerializer < ActiveModel::Serializer
attributes :number, :plan_meals
def plan_meals
#how to be able to use this line in Serilizer? !important
#plan = Plan.find(params[:id])
object.meals.map do |meal|
if meal.plan_id == #plan.id
MealSerializer.new(meal, scope: scope, root: false, event: object)
end
end
end
end
target reason response :
{
id: 8,
name: "Plan1",
monthly_price: 88,
plan_days: [
{
number: 5,
plan_meals: [],
},
{
number: 4,
plan_meals: [],
},
{
number: 3,
plan_meals: [],
},
{
number: 2,
plan_meals: [],
},
{
number: 1,
plan_meals: [
{
id: 11,
name: "test meal",
calories: 32,
protein: 32,
fat: 32,
carbohydrates: 32,
plan_id: 8,
},
],
},
],
}
currently it's showing all meals that belongs to each day,
not only the meals with the plan_id = Plan.find(params[:id])

Answer 1

In general I think you could use something like this should work.
ActiveModel::Serializer::CollectionSerializer.new. It actually by itself allows you to pass additional information to your serializer. It does the same as your current code just you are able to explicitly pass new data.
Controller:
def meals
#plan = Plan.find(params[:id])
#days = #plan.days
#meals = Meal.where("plan_id = ? ", #plan.id)
render :json => {
:plan => #plan,
:days => ActiveModel::Serializer::CollectionSerializer.new(#days, serializer: DaySerializer, plan_id: #plan.id),
:meals => #meals
}
end
And then in DaySerializer:
class DaySerializer < ActiveModel::Serializer
attributes :number, :plan_meals
def plan_meals
object.meals.map do |meal|
if meal.plan_id == instance_options[:plan_id]
MealSerializer.new(meal, scope: scope, root: false, event: object)
end
end
end
end
So in short ActiveModel::Serializer::CollectionSerializer.new in controller and instance_options in serializer to access passed additional parameters.

Answer 2

UPDATED:
How about add meal serializer?
class MealSerializer < ActiveModel::Serializer
attributes :id, :name, :calories, :protein, :fat, # etc
end
class DaySerializer < ActiveModel::Serializer
attributes :number
has_many :meals, serializer: MealSerializer
end
ORIGINAL:
class PlanSerializer < ActiveModel::Serializer
attributes :id, :name, :monthly_price, :plan_days
has_many :plan_days, serializer: DaySerializer
end
something like this.