RelationToJSON

RelationToJSON allows the conversion of ActiveRecord::Relation objects into an array of hash-like objects, provided a schema. It allows nesting across different relations, and uses pluck to optimize queries over multiple tables. This also acts as a useful interface in a React on Rails application where data needs to be passed to the front end in a simple serializable object, rather than passing a Rails object.

Installation

Add this line to your application's Gemfile

gem 'relation_to_json'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install relation_to_json

Usage

A schema is an array of attributes that you would like your resultant JSON object to have.

class User < ApplicationRecord
  has_one :keyboard
  validate :first_name, :last_name, presence: true
end

class Keyboard < ApplicationRecord
  belongs_to :user
  validate :make, :model, presence: true
end

You can write the following schema:

[
  :first_name,
  :last_name,
  keyboard: [
    :make,
    :model,
  ]
]

Thus with the following ActiveRecord::Relation, such as User.all, we can write out the following:

User.all.to_json_with_schema(schema)

Assuming that all of the relations exist, we can expect a response of the format:

[
  {
    id: 1,
    first_name: ...,
    last_name: ...,
    keyboard: {
      make: ...,
      model: ...,
    }
  },
  {
    id: 2,
    first_name: ...,
    last_name: ...,
    keyboard: {
      make: ...,
      model: ...,
    }
  }
]

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on Github at https://github.com/DerekYu177/relation_to_json.

License

This gem is available as open source under the terms of the MIT License.