Class: Perpetuity::MongoDB::Serializer

Inherits:
Object
  • Object
show all
Includes:
DataInjectable
Defined in:
lib/perpetuity/mongodb/serializer.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from DataInjectable

#give_id_to, #inject_attribute, #inject_data

Constructor Details

#initialize(mapper) ⇒ Serializer

Returns a new instance of Serializer.



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# File 'lib/perpetuity/mongodb/serializer.rb', line 11

def initialize(mapper)
  @mapper = mapper
  @class = mapper.mapped_class
  @mapper_registry = mapper.mapper_registry
end

Instance Attribute Details

#mapper ⇒ Object (readonly)

Returns the value of attribute mapper.



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# File 'lib/perpetuity/mongodb/serializer.rb', line 9

def mapper
  @mapper
end

#mapper_registry ⇒ Object (readonly)

Returns the value of attribute mapper_registry.



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# File 'lib/perpetuity/mongodb/serializer.rb', line 9

def mapper_registry
  @mapper_registry
end

Instance Method Details

#attribute_for(object, attribute_name) ⇒ Object 



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# File 'lib/perpetuity/mongodb/serializer.rb', line 17

def attribute_for object, attribute_name
  object.instance_variable_get("@#{attribute_name}")
end

#has_attribute?(object, attribute_name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/perpetuity/mongodb/serializer.rb', line 21

def has_attribute? object, attribute_name
  object.instance_variable_defined? "@#{attribute_name}"
end

#marshal(value) ⇒ Object 



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# File 'lib/perpetuity/mongodb/serializer.rb', line 162

def marshal value
  {
    '__marshaled__' => true,
    'value' => Marshal.dump(value)
  }
end

#serialize(object) ⇒ Object 



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# File 'lib/perpetuity/mongodb/serializer.rb', line 25

def serialize object
  attrs = mapper.attribute_set.map do |attrib|
    next unless has_attribute? object, attrib.name

    value = attribute_for object, attrib.name

    serialized_value = if value.is_a? Reference
      serialize_reference value
    elsif value.is_a? Array
      serialize_array(value, attrib.embedded?)
    elsif mapper.data_source.can_serialize? value
      value
    elsif mapper_registry.has_mapper?(value.class)
      serialize_with_foreign_mapper(value, attrib.embedded?)
    else
      marshal(value)
    end

    [attrib.name.to_s, serialized_value]
  end

  Hash[attrs.compact]
end

#serialize_array(enum, embedded) ⇒ Object 



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# File 'lib/perpetuity/mongodb/serializer.rb', line 121

def serialize_array enum, embedded
  enum.map do |value|
    if value.is_a? Reference
      serialize_reference value
    elsif value.is_a? Array
      serialize_array(value)
    elsif mapper.data_source.can_serialize? value
      value
    elsif mapper_registry.has_mapper?(value.class)
      if embedded
        {
          '__metadata__' => {
            'class' => value.class.to_s
          }
        }.merge mapper_registry[value.class].serialize(value)
      else
        serialize_reference value
      end
    else
      marshal value
    end
  end
end

#serialize_changes(changed, original) ⇒ Object 



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# File 'lib/perpetuity/mongodb/serializer.rb', line 49

def serialize_changes changed, original
  Hash[Array(serialize(changed)) - Array(serialize(original))]
end

#serialize_reference(value) ⇒ Object 



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# File 'lib/perpetuity/mongodb/serializer.rb', line 145

def serialize_reference value
  if value.is_a? Reference
    reference = value
  else
    unless mapper.persisted? value
      mapper_registry[value.class].insert value
    end
    reference = Reference.new(value.class.to_s, mapper.id_for(value))
  end
  {
    '__metadata__' => {
      'class' => reference.klass.to_s,
      'id'    => reference.id
    }
  }
end

#serialize_with_foreign_mapper(value, embedded = false) ⇒ Object 



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# File 'lib/perpetuity/mongodb/serializer.rb', line 110

def serialize_with_foreign_mapper value, embedded = false
  if embedded
    value_mapper = mapper_registry[value.class]
    value_serializer = Serializer.new(value_mapper)
    attr = value_serializer.serialize(value)
    attr.merge '__metadata__' =>  { 'class' => value.class }
  else
    serialize_reference(value)
  end
end

#unmarshal(value) ⇒ Object 



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# File 'lib/perpetuity/mongodb/serializer.rb', line 169

def unmarshal value
  Marshal.load(value)
end

#unserialize(data) ⇒ Object 



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# File 'lib/perpetuity/mongodb/serializer.rb', line 53

def unserialize data
  if data.is_a? Array
    unserialize_object_array data
  else
    object = unserialize_object(data)
    give_id_to object
    object
  end
end

#unserialize_attribute(data) ⇒ Object 



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# File 'lib/perpetuity/mongodb/serializer.rb', line 83

def unserialize_attribute data
  return data.map { |i| unserialize_attribute i } if data.is_a? Array
  return data unless data.is_a? Hash
  metadata  = data.fetch("__metadata__", {})
  marshaled = data.fetch("__marshaled__", false)

  if marshaled
    value = data.fetch("value")
    return unmarshal(value)
  end

  if metadata.any?
    klass = metadata['class'].split('::').inject(Kernel) do |scope, const_name|
      scope.const_get(const_name)
    end
    id = metadata['id']

    if id
      Reference.new(klass, id)
    else
      unserialize_object(data, klass)
    end
  else
    data
  end
end

#unserialize_object(data, klass = @class) ⇒ Object 



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# File 'lib/perpetuity/mongodb/serializer.rb', line 63

def unserialize_object data, klass=@class
  if data.is_a? Hash
    object = klass.allocate
    data.each do |attr, value|
      inject_attribute object, attr, unserialize_attribute(value)
    end
    object
  else
    unserialize_attribute data
  end
end

#unserialize_object_array(objects) ⇒ Object 



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# File 'lib/perpetuity/mongodb/serializer.rb', line 75

def unserialize_object_array objects
  objects.map do |data|
    object = unserialize_object data
    give_id_to object
    object
  end
end