--- /dev/null
+module ActiveRecord #:nodoc:
+ module Serialization
+ class Serializer #:nodoc:
+ attr_reader :options
+
+ def initialize(record, options = {})
+ @record, @options = record, options.dup
+ end
+
+ # To replicate the behavior in ActiveRecord#attributes,
+ # <tt>:except</tt> takes precedence over <tt>:only</tt>. If <tt>:only</tt> is not set
+ # for a N level model but is set for the N+1 level models,
+ # then because <tt>:except</tt> is set to a default value, the second
+ # level model can have both <tt>:except</tt> and <tt>:only</tt> set. So if
+ # <tt>:only</tt> is set, always delete <tt>:except</tt>.
+ def serializable_attribute_names
+ attribute_names = @record.attribute_names
+
+ if options[:only]
+ options.delete(:except)
+ attribute_names = attribute_names & Array(options[:only]).collect { |n| n.to_s }
+ else
+ options[:except] = Array(options[:except]) | Array(@record.class.inheritance_column)
+ attribute_names = attribute_names - options[:except].collect { |n| n.to_s }
+ end
+
+ attribute_names
+ end
+
+ def serializable_method_names
+ Array(options[:methods]).inject([]) do |method_attributes, name|
+ method_attributes << name if @record.respond_to?(name.to_s)
+ method_attributes
+ end
+ end
+
+ def serializable_names
+ serializable_attribute_names + serializable_method_names
+ end
+
+ # Add associations specified via the <tt>:includes</tt> option.
+ # Expects a block that takes as arguments:
+ # +association+ - name of the association
+ # +records+ - the association record(s) to be serialized
+ # +opts+ - options for the association records
+ def add_includes(&block)
+ if include_associations = options.delete(:include)
+ base_only_or_except = { :except => options[:except],
+ :only => options[:only] }
+
+ include_has_options = include_associations.is_a?(Hash)
+ associations = include_has_options ? include_associations.keys : Array(include_associations)
+
+ for association in associations
+ records = case @record.class.reflect_on_association(association).macro
+ when :has_many, :has_and_belongs_to_many
+ @record.send(association).to_a
+ when :has_one, :belongs_to
+ @record.send(association)
+ end
+
+ unless records.nil?
+ association_options = include_has_options ? include_associations[association] : base_only_or_except
+ opts = options.merge(association_options)
+ yield(association, records, opts)
+ end
+ end
+
+ options[:include] = include_associations
+ end
+ end
+
+ def serializable_record
+ returning(serializable_record = {}) do
+ serializable_names.each { |name| serializable_record[name] = @record.send(name) }
+ add_includes do |association, records, opts|
+ if records.is_a?(Enumerable)
+ serializable_record[association] = records.collect { |r| self.class.new(r, opts).serializable_record }
+ else
+ serializable_record[association] = self.class.new(records, opts).serializable_record
+ end
+ end
+ end
+ end
+
+ def serialize
+ # overwrite to implement
+ end
+
+ def to_s(&block)
+ serialize(&block)
+ end
+ end
+ end
+end
+
+require 'active_record/serializers/xml_serializer'
+require 'active_record/serializers/json_serializer'
\ No newline at end of file