activerecord_json_validator: A Ruby repository from tyler-wel

ActiveRecord::JSONValidator makes it easy to validate
JSON attributes against a JSON schema.

Installation

Add this line to your application's Gemfile:

gem 'activerecord_json_validator'

Usage

JSON Schema

{
  "type": "object",
  "$schema": "http://json-schema.org/draft-04/schema",
  "properties": {
    "city": { "type": "string" },
    "country": { "type": "string" }
  },
  "required": ["country"]
}

Ruby

create_table "users" do |t|
  t.string "name"
  t.json "profile" # First-class JSON with PostgreSQL, yo.
end

class User < ActiveRecord::Base
  # Constants
  PROFILE_JSON_SCHEMA = Rails.root.join('config', 'schemas', 'profile.json_schema').to_s

  # Validations
  validates :name, presence: true
  validates :profile, presence: true, json: { schema: PROFILE_JSON_SCHEMA }
end

user = User.new(name: 'Samuel Garneau', profile: { city: 'Quebec City' })
user.valid? # => false

user = User.new(name: 'Samuel Garneau', profile: { city: 'Quebec City', country: 'Canada' })
user.valid? # => true

user = User.new(name: 'Samuel Garneau', profile: '{invalid JSON":}')
user.valid? # => false
user.profile_invalid_json # => '{invalid JSON":}'

Options

Option	Description
`:schema`	The JSON schema to validate the data against (see Schema section)
`:message`	The ActiveRecord message added to the record errors (see Message section)
`:options`	A `Hash` of `json-schema`-supported options to pass to the validator

Schema

ActiveRecord::JSONValidator uses the json-schema gem to validate the JSON data against a JSON schema. You can use any value that JSON::Validator.validate would take as the schema argument.

Additionally, you can use a Symbol or a Proc. Both will be executed in the context of the validated record (Symbol will be sent as a method and the Proc will be instance_execed)

class User < ActiveRecord::Base
  # Constants
  PROFILE_REGULAR_JSON_SCHEMA = Rails.root.join('config', 'schemas', 'profile.json_schema').to_s
  PROFILE_ADMIN_JSON_SCHEMA = Rails.root.join('config', 'schemas', 'profile_admin.json_schema').to_s

  # Validations
  validates :profile, presence: true, json: { schema: lambda { dynamic_profile_schema } } # `schema: :dynamic_profile_schema` would also work

  def dynamic_profile_schema
    admin? ? PROFILE_ADMIN_JSON_SCHEMA : PROFILE_REGULAR_JSON_SCHEMA
  end
end

Message

Like any other ActiveModel validation, you can specify either a Symbol or String value for the :message option. The default value is :invalid_json.

However, you can also specify a Proc that returns an array of errors. The Proc will be called with a single argument — an array of errors returned by the JSON schema validator. So, if you’d like to add each of these errors as a first-level error for the record, you can do this:

class User < ActiveRecord::Base
  # Validations
  validates :profile, presence: true, json: { message: ->(errors) { errors }, schema: 'foo.json_schema' }
end

user = User.new.tap(&:valid?)
user.errors.full_messages
# => [
#      'The property '#/email' of type Fixnum did not match the following type: string in schema 2d44293f-cd9d-5dca-8a6a-fb9db1de722b#',
#      'The property '#/full_name' of type Fixnum did not match the following type: string in schema 2d44293f-cd9d-5dca-8a6a-fb9db1de722b#',
#    ]

License

The tree logo is based on this lovely icon by Sara Quintana, from The Noun Project. Used under a Creative Commons BY 3.0 license.

About Mirego

Mirego is a team of passionate people who believe that work is a place where you can innovate and have fun. We're a team of talented people who imagine and build beautiful Web and mobile applications. We come together to share ideas and change the world.

We also love open-source software and we try to give back to the community as much as we can.

tyler-wel/activerecord_json_validator