Ika

Ika implements the function that export/import ActiveModel data with json.

Installation

In Rails, add it to your Gemfile:

gem 'ika'

Usage

In case: Group has many tags and User belongs to multiple groups with GroupUsers such as below.

class User < ActiveRecord::Base
  has_many :group_users
  has_many :groups, through: :group_users
end

class GroupUsers < ActiveRecord::Base
  belongs_to :user
  belongs_to :group
end

class Group < ActiveRecord::Base
  has_many :group_users
  has_many :users, through: :group_users
  has_many :tags
end

class Tag < ActiveRecord::Base
  belongs_to :group
end

Now you can export with export method on your model or relation.

require 'json'
# with no options

JSON.parse User.export
# => [{"id":1,"name":"iruca3"},{"id":2,"name":"inkling"}]
JSON.parse User.where(id: 1).export
# => [{"id":1,"name":"iruca3"}]
JSON.parse User.find(id: 2).export
# => {"id":2,"name":"inkling"}

# with include option
JSON.parse User.export(include: :groups)
# => [{"id":1,"name":"iruca3","groups":[{"id":1,"name":"aqutras"},{"id":2,"name":"Splatoon"}]},{"id":2,"name":"inkling","groups":[{"id":2,"name":"Splatoon"}]}]
JSON.parse User.find(id: 1).export(include: [{groups: [:tags]}])
# => {"id":1,"name":"iruca3","groups":[{"id":1,"name":"aqutras","tags":[{"id":1,"name":"Company"}]},{"id":2,"name":"Splatoon","tags":[{"id":2,"name":"Game"},{"id":3,"name":"Inkling"}]}]}

This project rocks and uses MIT-LICENSE.