Mongoid::Denormalize

Helper module for denormalizing association attributes in Mongoid models.

This gem is tested on mongoid 6.x and 7.x.

Installation

Add this line to your application's Gemfile:

gem 'mongoid-denormalize'

And then execute:

$ bundle

Or install it yourself as:

$ gem install mongoid-denormalize

Usage

In your model:

# Include the helper method
include Mongoid::Denormalize

# Define your denormalized fields
denormalize :name, :email, from: :user

You need to add inverse_of to belongs_to side if relation name is diferent from model:

class Club
  ...
  has_many :members, class_name: 'User'
end

class User
  ...
  belogns_to club, inverse_of: :members

  denormalize :name, from: :club
end

Example

class User
  include Mongoid::Document

  field :name

  has_many :books
end

class Book
  include Mongoid::Document
  include Mongoid::Denormalize

  field :title

  belongs_to :author

  denormalize :name, from: :author
end

>> user = User.create(name: 'User1')
>> book = Book.create(title: 'Title', author: user)
>> book.author_name
"User1"

>> user.update_attributes(name: 'User1.1')
>> book.reload.author_name
"User1.1"

>> new_user = User.create(name: 'User2')
>> book.update_attributes(author: new_user)
>> book.reload.author_name
"User2"

Options of denormalize

as

Enables to customize the final field name

  denormalize :name, from: :top, as: :custom_name

It will create the field custom_name with the content of top.name. Also support an array:

  denormalize :name, :age, from: :top, as: [:custom_name, :custom_age]

prefix

In somes cases it could be interesting to customize the prefix of the final name, instead of using the basic from_field

  denormalize :color, :name, from: :top, prefix: :ancestor

It will create the fields ancestor_name and ancestor_color with the content of top.name and top.color.

child_callback

By default when a child is created the denormalization is executed into before_save hook.
This option let you change this callback by other, for example:

  denormalize :name, from: :top, child_callback: :before_validation

  validate :top_name, presence: true

It will denormalize field name into before_validation callback so that we can validate it.

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 tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/nosolosoftware/mongoid-denormalize.

License

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