module Elasticsearch module Model # This module provides a proxy interfacing between the including class and # {Elasticsearch::Model}, preventing the pollution of the including class namespace. # # The only "gateway" between the model and Elasticsearch::Model is the # `__elasticsearch__` class and instance method. # # The including class must be compatible with # [ActiveModel](https://github.com/rails/rails/tree/master/activemodel). # # @example Include the {Elasticsearch::Model} module into an `Article` model # # class Article < ActiveRecord::Base # include Elasticsearch::Model # end # # Article.__elasticsearch__.respond_to?(:search) # # => true # # article = Article.first # # article.respond_to? :index_document # # => false # # article.__elasticsearch__.respond_to?(:index_document) # # => true # module Proxy # Define the `__elasticsearch__` class and instance methods in the including class # and register a callback for intercepting changes in the model. # # @note The callback is triggered only when `Elasticsearch::Model` is included in the # module and the functionality is accessible via the proxy. # def self.included(base) base.class_eval do # {ClassMethodsProxy} instance, accessed as `MyModel.__elasticsearch__` # def self.__elasticsearch__ &block @__elasticsearch__ ||= ClassMethodsProxy.new(self) @__elasticsearch__.instance_eval(&block) if block_given? @__elasticsearch__ end # {InstanceMethodsProxy}, accessed as `@mymodel.__elasticsearch__` # def __elasticsearch__ &block @__elasticsearch__ ||= InstanceMethodsProxy.new(self) @__elasticsearch__.instance_eval(&block) if block_given? @__elasticsearch__ end # Register a callback for storing changed attributes for models which implement # `before_save` and `changed_attributes` methods (when `Elasticsearch::Model` is included) # # @see http://api.rubyonrails.org/classes/ActiveModel/Dirty.html # before_save do |i| changed_attr = i.__elasticsearch__.instance_variable_get(:@__changed_attributes) || {} i.__elasticsearch__.instance_variable_set(:@__changed_attributes, changed_attr.merge(Hash[ i.changes.map { |key, value| [key, value.last] } ])) end if respond_to?(:before_save) && instance_methods.include?(:changed_attributes) end end # @overload dup # # Returns a copy of this object. Resets the __elasticsearch__ proxy so # the duplicate will build its own proxy. def initialize_dup(_) @__elasticsearch__ = nil super end # Common module for the proxy classes # module Base attr_reader :target def initialize(target) @target = target end # Delegate methods to `@target` # def method_missing(method_name, *arguments, &block) target.respond_to?(method_name) ? target.__send__(method_name, *arguments, &block) : super end # Respond to methods from `@target` # def respond_to?(method_name, include_private = false) target.respond_to?(method_name) || super end def inspect "[PROXY] #{target.inspect}" end end # A proxy interfacing between Elasticsearch::Model class methods and model class methods # # TODO: Inherit from BasicObject and make Pry's `ls` command behave? # class ClassMethodsProxy include Base end # A proxy interfacing between Elasticsearch::Model instance methods and model instance methods # # TODO: Inherit from BasicObject and make Pry's `ls` command behave? # class InstanceMethodsProxy include Base def klass target.class end def class klass.__elasticsearch__ end # Need to redefine `as_json` because we're not inheriting from `BasicObject`; # see TODO note above. # def as_json(options={}) target.as_json(options) end end end end end