rom-http-repo-with-mapper.rb

require 'json'
require 'uri'
require 'net/http'

gemfile(true) do
  gem 'anima'
  gem 'rom'
  gem 'rom-http'
  gem 'rom-repository'
end

module ROM
  module MyAdapter
    class Dataset < ROM::HTTP::Dataset
      default_request_handler ->(dataset) do
        uri = URI(dataset.uri)
        uri.path = "/#{dataset.name}/#{dataset.path}"
        uri.query = URI.encode_www_form(dataset.params)

        http = Net::HTTP.new(uri.host, uri.port)
        request_klass = Net::HTTP.const_get(ROM::Inflector.classify(dataset.request_method))

        request = request_klass.new(uri.request_uri)
        dataset.headers.each_with_object(request) do |(header, value), request|
          request[header.to_s] = value
        end

        response = http.request(request)
      end

      default_response_handler ->(response, dataset) do
        Array([JSON.parse(response.body, symbolize_names: true)]).flatten
      end
    end

    class Gateway < ROM::HTTP::Gateway; end

    class Relation < ROM::HTTP::Relation
      adapter :my_adapter
    end

    module Commands
      class Create < ROM::HTTP::Commands::Create
        adapter :my_adapter
      end

      class Update < ROM::HTTP::Commands::Update
        adapter :my_adapter
      end

      class Delete < ROM::HTTP::Commands::Delete
        adapter :my_adapter
      end
    end
  end
end

ROM.register_adapter(:my_adapter, ROM::MyAdapter)

configuration = ROM::Configuration.new(:my_adapter, {
  uri: 'http://jsonplaceholder.typicode.com',
  headers: {
    Accept: 'application/json'
  }
})

class User
  ATTRIBUTES = %i(id name username email phone website).freeze

  include Anima.new(*ATTRIBUTES)
end

class Users < ROM::Relation[:my_adapter]
  dataset :users
  register_as :users

  schema do
    attribute :id, ROM::Types::Int
    attribute :name, ROM::Types::String
    attribute :username, ROM::Types::String
    attribute :email, ROM::Types::String
    attribute :phone, ROM::Types::String
    attribute :website, ROM::Types::String
  end

  view(:base, User::ATTRIBUTES) do
    self
  end

  def by_id(id)
    with_path(id.to_s)
  end
end

configuration.register_relation(Users)
container = ROM.container(configuration)

class UserRepository < ROM::Repository[:users]
  def find(id)
    users.by_id(id).as(User).one!
  end
end

user_repo = UserRepository.new(container)
user_repo.find(1)