Koine::Repository

If you want to use repository pattern as your way into the database

Changelog

• Here you can find the changelog.

Installation

Add this line to your application's Gemfile:

gem 'koine-repository'

And then execute:

$ bundle

Or install it yourself as:

$ gem install koine-repository

Usage

Given you have a table called articles with fields:

• id
• body
• title
• published

You can create your entity as follows:

class Article
  attr_accessor :id, :body, :title, :published
end

Then you can create a repository class for your articles

class ArticlesRepository < Koine::Repository::Repository
  # adds methods find(id), create(entity) and update(entity)
  include Koine::Repository::Repository::IdAwareEntity

  def published
    find_all_by(published: true)
  end
end

Putting all together:

With repositories nothing is magic. You need to instantiate your classes and give them their dependencies.

Then you can start using your classes. Here is how you manually instantiate your classes:

db_adapter = Sequel.connect(db_string)

articles_storage = ::Koine::Repository::Persistence::Adapter::Sql.new(
  db_adapter,
  :articles
)

repository = ArticlesRepository.new(articles_adapter)

To make creation of objects easier, you should use factories or some kind of dependency injection solution.

It could be as in the example bellow;

container = ApplicationDependencies.new

container.set(:db_connection) do |di|
  Sequel.connect("mysql://root@localhost/some_db")
end

container.set(:articles_persistence) do |di|
  Koine::Repository::Persistence::Sql.new(
    di.get(:db_connection),
    :articles
  )
end

container.set(ArticlesRepository) do |di|
  repository                  = ArticlesRepository.new(di.get(:articles_persistence))
  repository.hydrator         = Koine::Hydrator::Hydrator.new
  repository.entity_prototype = Article.new

  repository
end

Using your repository:

Accessing the repository in your controller:

class ArticlesController < MyBaseController
  def index
    @articles = repository.published
  end

  def create
    @article = Article.new
    set_attributes(@article)

    # validate as you wish

    repository.create(@article)

    redirect_to :articles_path, notice: "Article with id #{@article.id} created"
  end

  def update
    @article = repository.find(params[:id])
    set_attributes(@article)

    # validate

    repository.update(@article)
  end

  def destroy
    @article = repository.find(params[:id])
    repository.remove(@article)
  end

  private

  def set_attributes(article)
    article.title     = params[:title]
    article.body      = params[:body]
    article.published = params[:published]
  end

  def repository
    @repository ||= dependencies.get(ArticlesRepository)
  end
end

Development

After checking out the repo, run bin/setup to install dependencies. Then, 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 to create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

1. Fork it ( https://github.com/mjacobus/koine-repository/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request