Dao::Repository

Installation

Add this line to your application's Gemfile:

gem 'dao-repository'

And then execute:

$ bundle

Or install it yourself as:

$ gem install dao-repository

Built-in methods

Repositories in dao-rb are objects that allow you map your data into entities and save them through data gateway.

Basic methods of each repository:

1. Repository.all should return all data.
2. Repository.find should find entity with given id. You can return entity with its relations by adding a list of them into the second argument (Repository.find(1, with: [:author, :comments])), but your gateway should support eager loading. If entity was not found then method will raise an exception.
3. Repository.find_by_id also should find entity with given id, but if it was not found then method return nil.
4. Repository.last should return last entity. You can return entity with its relations by adding a list of them into the first argument (Repository.last(with: [:author, :comments])), but your gateway should support eager loading.
5. Repository.count should return count of entities.
6. Repository.build should build entity from data object.
7. Repository.save should save changes in entity.
8. Repository.save_all should save collection of entities.
9. Repository.delete should delete entity.
10. Repository.delete_by_id should delete entity by id.
11. Repository.with_transaction(&block) execute block in transaction if gateway support it.
12. Repository.with_lock(id, *args, &block) in transaction: locks (with given arguments) db record with given id, execute block if gateway support it.
13. Repository.by_criteria should return entities by given criteria.
14. Repository.by_criteria_count should return count of elements by given criteria.

Usage example

require 'dao/entity'
require 'dao/repository'
require 'dao/gateway/active_record'

class Comment < ApplicationRecord
end

class Post < ApplicationRecord
  has_many :comments
end

class CommentEntity < Dao::Entity::Base
  attribute :body, String
end

class PostEntity < Dao::Entity::Base
  attribute :id,       Integer
  attribute :body,     String

  attribute :comments, Array[CommentEntity]
end

class PostRepository < Dao::Repository::Base
  entity PostEntity
  gateway Dao::Gateway::ActiveRecord::Base, Post, Dao::Gateway::ActiveRecord::BaseTransformer
end

post = PostRepository.last(with: :comments)

post.id # => 1
post.body # => "Post body"
post.comments # => [#<CommentEntity:0x007ffdcb923a30>]

Custom methods

You can define custom methods in your repository:

class Post < ApplicationRecord
  has_many :comments

  scope :deleted, -> { where(deleted: true) }
end

class PostRepository < Dao::Repository::Base
  entity PostEntity
  gateway Dao::Gateway::ActiveRecord::Base, Post, Dao::Gateway::ActiveRecord::BaseTransformer

  def self.deleted
    scope.deleted(with: :comments).apply # it will return deleted posts with loaded comments.
  end
end

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/dao-rb/dao-repository.

License

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