Generate a nested JSON array in JBuilder - ruby-on-rails

Question

I have this models in ruby on rails
Branch model: has_many :menus
class Branch < ActiveRecord::Base
belongs_to :place
belongs_to :city
has_many :menus , dependent: :destroy
belongs_to :type_place
end
Menu model: has_many :products
class Menu < ActiveRecord::Base
attr_accessible :description, :product_name, :price, :category_id, :menu_id
belongs_to :branch
has_many :products, dependent: :destroy
end
Product model:
class Product < ActiveRecord::Base
belongs_to :menu
belongs_to :category
end
with the following code in the view:
if #condition
json.code :success
json.branch do
json.array!(#branches) do |json, branch|
json.(branch, :id, :branch_name, :barcode)
json.menu branch.menus, :id, :menu_name
end
end
else
json.code :error
json.message 'Mensaje de error'
end
gets:
{
"code": "success",
"branch": [
{
"id": 1,
"branch_name": "Sucursal 1",
"barcode": "zPOuByzEFe",
"menu": [
{
"id": 2,
"menu_name": "carta sucursal 1"
}
]
},
{
"id": 2,
"branch_name": "Sucursal Viña Centro",
"barcode": "RlwXjAVtfx",
"menu": [
{
"id": 1,
"menu_name": "carta viña centro"
},
{
"id": 5,
"menu_name": "carta viña centro vinos"
}
]
},
{
"id": 3,
"branch_name": "dddd",
"barcode": "eSbJqLbsyP",
"menu": [
]
}
]
}
But as I get the products of each menu?, I suspect I need to iterate menu, but I have tried several ways without success.

Answer 1

I'm not sure which attributes your product can have but i would try something like:
if #condition
json.code :success
json.array!(#branches) do |json, branch|
json.(branch, :id, :branch_name, :barcode)
json.menus branch.menus do |json,menue|
json.id menue.id
json.menu_name menue.menu_name
json.products menue.products do |json, product|
json.product_attribute_1 product.product_attribute_1
end
end
end
else
json.code :error
json.message 'Mensaje de error'
end
i'm also not quite sure why you try to nest #branches under a branch as stated by:
json.branch do
...
end
i just removed that.

Answer 2

This is from the docs ("this" is the "json.array! method) http://www.rubydoc.info/github/rails/jbuilder/Jbuilder:array!
It's generally only needed to use this method for top-level arrays. If
you have named arrays, you can do:
json.people(#people) do |person|
json.name person.name
json.age calculate_age(person.birthday)
end
{ "people": [ { "name": David", "age": 32 }, { "name": Jamie", "age": 31 } ] }
I had unexpected behaviors using array! and regular iteration as suggested worked perfectly and made my code very readable:
json.user do
json.email #user.email
json.devices #user.devices do |device|
json.partial! 'devices/device', device: device
end
end