Contents

module OrmAdapter
  class Base
    attr_reader :klass

    # Your ORM adapter needs to inherit from this Base class and its adapter
    # will be registered. To create an adapter you should create an inner
    # constant "OrmAdapter" e.g. ActiveRecord::Base::OrmAdapter
    #
    # @see orm_adapters/active_record
    # @see orm_adapters/datamapper
    # @see orm_adapters/mongoid
    def self.inherited(adapter)
      OrmAdapter.adapters << adapter
      super
    end

    # Gets a list of the available models for this adapter
    def self.model_classes
      raise NotImplementedError, "return a list of available models for this adapter"
    end

    def initialize(klass)
      @klass = klass
    end

    # Get a list of column/property/field names
    def column_names
      raise NotSupportedError
    end
    
    # Get an instance by id of the model. Raises an error if a model is not found.
    # This should comply with ActiveModel#to_key API, i.e.:
    #
    #   User.to_adapter.get!(@user.to_key) == @user
    #
    def get!(id)
      raise NotSupportedError
    end

    # Get an instance by id of the model. Returns nil if a model is not found.
    # This should comply with ActiveModel#to_key API, i.e.:
    #
    #   User.to_adapter.get(@user.to_key) == @user
    #
    def get
      raise NotSupportedError
    end

    # Find the first instance matching conditions
    def find_first(conditions)
      raise NotSupportedError
    end

    # Find all models matching conditions
    def find_all(conditions)
      raise NotSupportedError
    end

    # Create a model using attributes
    def create!(attributes)
      raise NotSupportedError
    end

    protected

    def wrap_key(key)
      key.is_a?(Array) ? key.first : key
    end
  end

  class NotSupportedError < NotImplementedError
    def to_s
      "method not supported by this orm adapter"
    end
  end
end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
orm_adapter-0.0.3	lib/orm_adapter/base.rb
orm_adapter-0.0.2	lib/orm_adapter/base.rb