Module: Protobuf::ActiveRecord::Transformation::ClassMethods

Defined in:
lib/protobuf/active_record/transformation.rb

Instance Method Summary collapse

Instance Method Details

#_filter_attribute_fields(proto) ⇒ Object

Filters accessible attributes that exist in the given protobuf message’s fields or have attribute transformers defined for them.

Returns a hash of attribute fields with their respective values.

:nodoc:



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# File 'lib/protobuf/active_record/transformation.rb', line 28

def _filter_attribute_fields(proto)
  fields = proto.to_hash
  fields.select! do |key, value|
    field = proto.class.get_field(key, true)
    proto.has_field?(key) && !field.repeated?
  end

  filtered_attributes = _filtered_attributes + _protobuf_nested_attributes
  filtered_attributes += _protobuf_attribute_transformers.keys

  attribute_fields = filtered_attributes.inject({}) do |hash, column_name|
    symbolized_column = column_name.to_sym

    if fields.has_key?(symbolized_column) ||
      _protobuf_attribute_transformers.has_key?(symbolized_column)
      hash[symbolized_column] = fields[symbolized_column]
    end

    hash
  end

  attribute_fields
end

#_filtered_attributes ⇒ Object

Overidden by mass assignment security when protected attributes is loaded.

:nodoc:



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# File 'lib/protobuf/active_record/transformation.rb', line 55

def _filtered_attributes
  return self.attribute_names
end

#_protobuf_convert_fields_to_attributes(key, value) ⇒ Object

:nodoc:



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# File 'lib/protobuf/active_record/transformation.rb', line 60

def _protobuf_convert_fields_to_attributes(key, value)
  return value if value.nil?

  value = case
          when _protobuf_date_column?(key) then
            convert_int64_to_date(value)
          when _protobuf_datetime_column?(key) then
            convert_int64_to_datetime(value)
          when _protobuf_time_column?(key) then
            convert_int64_to_time(value)
          when _protobuf_timestamp_column?(key) then
            convert_int64_to_time(value)
          else
            value
          end

  return value
end

#attribute_from_proto(attribute, transformer = nil, &block) ⇒ Object

Define an attribute transformation from protobuf. Accepts a Symbol, callable, or block.

When given a callable or block, it is directly used to convert the field.

When a symbol is given, it extracts the method with the same name.

The callable or method must accept a single parameter, which is the proto message.

Examples:

attribute_from_proto :public_key, :extract_public_key_from_proto
attribute_from_proto :status, lambda { |proto| # Do some stuff... }
attribute_from_proto :status do |proto|
  # Do some blocky stuff...
end



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# File 'lib/protobuf/active_record/transformation.rb', line 96

def attribute_from_proto(attribute, transformer = nil, &block)
  transformer ||= block

  if transformer.is_a?(Symbol)
    callable = lambda { |value| self.__send__(transformer, value) }
  else
    callable = transformer
  end

  unless callable.respond_to?(:call)
    raise AttributeTransformerError
  end

  _protobuf_attribute_transformers[attribute.to_sym] = callable
end

#attributes_from_proto(proto) ⇒ Object

Creates a hash of attributes from a given protobuf message.

It converts and transforms field values using the field converters and attribute transformers, ignoring repeated and nil fields.



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# File 'lib/protobuf/active_record/transformation.rb', line 118

def attributes_from_proto(proto)
  attribute_fields = _filter_attribute_fields(proto)

  attributes = attribute_fields.inject({}) do |hash, (key, value)|
    if _protobuf_attribute_transformers.has_key?(key)
      attribute = _protobuf_attribute_transformers[key].call(proto)
      hash[key] = attribute unless attribute.nil?
    else
      hash[key] = _protobuf_convert_fields_to_attributes(key, value)
    end

    hash
  end

  attributes
end

#convert_int64_to_date(int64) ⇒ Object

:nodoc:



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# File 'lib/protobuf/active_record/transformation.rb', line 141

def convert_int64_to_date(int64)
  convert_int64_to_time(int64).utc.to_date
end

#convert_int64_to_datetime(int64) ⇒ Object

:nodoc:



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# File 'lib/protobuf/active_record/transformation.rb', line 146

def convert_int64_to_datetime(int64)
  convert_int64_to_time(int64).to_datetime
end

#convert_int64_to_time(int64) ⇒ Object

:nodoc:



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# File 'lib/protobuf/active_record/transformation.rb', line 136

def convert_int64_to_time(int64)
  Time.at(int64.to_i)
end