Rails ActiveModel Serializer : Retrieving Deeply Nested ActiveRecord Association - ruby-on-rails

Question

I'm using ActiveModel::Serializer to serialize my json data.
I have three models as follows
class Invoice < ApplicationRecord
has_many :invoiceDetails, inverse_of: :invoice
belongs_to :customer
accepts_nested_attributes_for :invoiceDetails
end
class InvoiceDetail < ApplicationRecord
belongs_to :invoice
belongs_to :product
end
class Product < ApplicationRecord
belongs_to :company
belongs_to :category
belongs_to :user
has_many :invoice_details
end
The serializers are as follows :
class InvoiceSerializer < ActiveModel::Serializer
attributes :id, :total_amount, :balance_amount, :created_at
belongs_to :customer
has_many :invoiceDetails
end
class InvoiceDetailSerializer < ActiveModel::Serializer
attributes :id, :quantity
belongs_to :product
belongs_to :invoice
end
class ProductSerializer < ActiveModel::Serializer
attributes :id, :name, :mrp, :sp, :cp, :stocks, :isPublished
has_one :category
end
When I retrieve an invoice I get the attributes from the associated invoiceDetails model and customer model but the attributes from the product model associated with the invoiceDetails model are missing.
For example if I retrieve an invoice, this is the output :
[
{
"id": 3,
"total_amount": 450,
"balance_amount": 350,
"created_at": "2017-06-27T17:02:20.000Z",
"customer": {
"id": 4,
"company_id": 1,
"name": "vivek",
"isActive": true,
"created_at": "2017-06-27T14:35:50.000Z",
"updated_at": "2017-06-27T14:35:50.000Z",
"mobile": "12345678",
"address": "test",
"pan_number": null,
"tin_number": null,
"party_name": "vipul jwelers"
},
"invoiceDetails": [
{
"id": 4,
"quantity": 1
},
{
"id": 5,
"quantity": 1
}
]
}
]
However if I retrieve invoiceDetail directly I get the associated model attributes.
**[
{
"id": 6,
"quantity": 5,
"product": {
"id": 4,
"name": "Test Prod",
"mrp": 150,
"sp": 130,
"cp": 100,
"stocks": 100,
"isPublished": true
},
"invoice": {
"id": 4,
"total_amount": 3903,
"balance_amount": 3,
"created_at": "2017-07-01T07:45:02.000Z"
}
},
{
"id": 7,
"quantity": 10,
"product": {
"id": 5,
"name": "Test Prod 2",
"mrp": 300,
"sp": 250,
"cp": 200,
"stocks": 10,
"isPublished": true
},
"invoice": {
"id": 4,
"total_amount": 3903,
"balance_amount": 3,
"created_at": "2017-07-01T07:45:02.000Z"
}
}
]**
So for retrieving the nested attributes directly from invoice, do I need to change the relationship among my models?
Has someone encountered the same problems, or any work around you can suggest?

Answer 1

If someone is stuck over this problem, here is what I did :
Whenever I want to retrieve the deeply nested association I add the "include **" keyword in the controller during response.
For example :
def show
cust_id = params[:customer_id]
invoice_id = params[:id]
if cust_id && invoice_id
invoice = Invoice.where(:id => invoice_id, :customer_id => cust_id)
render json: invoice, include: '**', status: 200
else
render json: { errors: "Customer ID or Invoice ID is NULL" }, status: 422
end
end
The include * * will retrieve all the nested attributes for the invoice model using the serializer if defined for the respective models.