Flushing out Mongoid sessions API to Moped.

sessions.rb

# encoding: utf-8
require "mongoid/sessions/factory"

module Mongoid #:nodoc:
  module Sessions
    extend ActiveSupport::Concern

    included do
      class_attribute :storage_options
    end

    def collection
      self.class.collection
    end

    # Get the name of the collection this model persists to. This will be
    # either the pluralized class name or the option defined in the store_in
    # macro.
    #
    # @example Get the collection name.
    #   Model.collection_name
    #
    # @return [ String ] The name of the collection.
    #
    # @since 3.0.0
    def collection_name
      self.class.collection_name
    end

    # Get the session for this model. This is determined in the following order:
    #
    #   1. Any custom configuration provided by the 'store_in' macro.
    #   2. The 'default' session as provided in the mongoid.yml
    #
    # @example Get the session.
    #   model.mongo_session
    #
    # @return [ Moped::Session ] The default moped session.
    #
    # @since 3.0.0
    def mongo_session
      self.class.mongo_session
    end

    # Tell the next persistance operation to store in a specific collection,
    # database or session.
    #
    # @example Save the current document to a different collection.
    #   model.with(collection: "secondary").save
    #
    # @example Save the current document to a different database.
    #   model.with(database: "secondary").save
    #
    # @example Save the current document to a different session.
    #   model.with(session: "replica_set").save
    #
    # @example Save with a combination of options.
    #   model.with(session: "sharded", database: "secondary").save
    #
    # @param [ Hash ] options The storage options.
    #
    # @option options [ String, Symbol ] :collection The collection name.
    # @option options [ String, Symbol ] :database The database name.
    # @option options [ String, Symbol ] :session The session name.
    #
    # @return [ Document ] The current document.
    #
    # @since 3.0.0
    def with(options)

    end

    module ClassMethods

      def collection
        mongo_session[collection_name]
      end

      # Get the name of the collection this model persists to. This will be
      # either the pluralized class name or the option defined in the store_in
      # macro.
      #
      # @example Get the collection name.
      #   Model.collection_name
      #
      # @return [ String ] The name of the collection.
      #
      # @since 3.0.0
      def collection_name
        @collection_name ||= __collection_name__
      end

      # Get the session for this model. This is determined in the following order:
      #
      #   1. Any custom configuration provided by the 'store_in' macro.
      #   2. The 'default' session as provided in the mongoid.yml
      #
      # @example Get the session.
      #   Model.mongo_session
      #
      # @return [ Moped::Session ] The default moped session.
      #
      # @since 3.0.0
      def mongo_session
        __session__.tap do |session|
          database = __database__
          session.use(database[:name])
        end
      end

      # Give this model specific custom default storage options.
      #
      # @example Store this model by default in "artists"
      #   class Band
      #     include Mongoid::Document
      #     store_in collection: "artists"
      #   end
      #
      # @example Store this model by default in the sharded db.
      #   class Band
      #     include Mongoid::Document
      #     store_in database: "echo_shard"
      #   end
      #
      # @example Store this model by default in a different session.
      #   class Band
      #     include Mongoid::Document
      #     store_in session: "secondary"
      #   end
      #
      # @example Store this model with a combination of options.
      #   class Band
      #     include Mongoid::Document
      #     store_in collection: "artists", database: "secondary"
      #   end
      #
      # @param [ Hash ] options The storage options.
      #
      # @option options [ String, Symbol ] :collection The collection name.
      # @option options [ String, Symbol ] :database The database name.
      # @option options [ String, Symbol ] :session The session name.
      #
      # @return [ Class ] The model class.
      #
      # @since 3.0.0
      def store_in(options)
        # @todo: Durran: Validate the options.
        self.storage_options = options
      end

      # Tell the next persistance operation to store in a specific collection,
      # database or session.
      #
      # @example Create a document in a different collection.
      #   Model.with(collection: "secondary").create(name: "test")
      #
      # @example Create a document in a different database.
      #   Model.with(database: "secondary").create(name: "test")
      #
      # @example Create a document in a different session.
      #   Model.with(session: "secondary").create(name: "test")
      #
      # @example Create with a combination of options.
      #   Model.with(session: "sharded", database: "secondary").create
      #
      # @param [ Hash ] options The storage options.
      #
      # @option options [ String, Symbol ] :collection The collection name.
      # @option options [ String, Symbol ] :database The database name.
      # @option options [ String, Symbol ] :session The session name.
      #
      # @return [ Class ] The model class.
      #
      # @since 3.0.0
      def with(options)

      end

      private

      # Get the name of the collection this model persists to.
      #
      # @example Get the collection name.
      #   Model.__collection_name__
      #
      # @return [ String ] The name of the collection.
      #
      # @since 3.0.0
      def __collection_name__
        if storage_options && name = storage_options[:collection]
          name.to_sym
        else
          self.name.collectionize.to_sym
        end
      end

      # Get the database configuration.
      #
      # @example Get the database configuration.
      #   Model.__database__
      #
      # @return [ Hash ] The db config.
      #
      # @since 3.0.0
      def __database__
        # @todo: Durran: Raise error if name not defined.
        if storage_options && name = storage_options[:database]
          Mongoid.databases[name.to_sym]
        else
          Mongoid.databases[:default]
        end
      end

      # Get the session for this class.
      #
      # @example Get the session.
      #   Model.__session__
      #
      # @return [ Moped::Session ] The moped session.
      #
      # @since 3.0.0
      def __session__
        if storage_options && name = storage_options[:session]
          Threaded.sessions[name.to_sym] ||= Sessions::Factory.create(name).tap
        else
          Threaded.sessions[:default] ||= Sessions::Factory.default
        end
      end
    end
  end
end