View Source OnePiece.Commanded.ProtobufMapper protocol (OnePiece.Commanded v0.24.0)

Protocol for encoding and decoding Protobuf structs.

The protocol is required when using the OnePiece.Commanded.EventStore.ProtobufJsonbSerializer serializer and working with Aggregate snapshotting. Since the Aggregates are not Protobuf structs, the serializer needs to encode and decode them to a Protobuf struct.

Example

defmodule MyApp.MyAggregate do
  alias MyApp.Proto.MyAggregateProto

  use OnePiece.Commanded.Aggregate, identifier: :id

  embedded_schema do
    field(:initiated?, :boolean, default: false)
  end
end


defimpl OnePiece.Commanded.ProtobufMapper, for: MyApp.MyAggregate do
  alias MyApp.MyAggregate
  alias MyApp.Proto.MyAggregateProto

  def message_module(%MyAggregate{} = _aggregate), do: MyAggregateProto

  def to_proto_message(%MyAggregate{} = aggregate) do
    %MyAggregateProto{
      id: aggregate.id,
      initiated: aggregate.initiated?
    }
  end

  def from_proto_message(%MyAggregate{} = aggregate, %MyAggregateProto{} = proto_message) do
    aggregate
    |> Map.put(:id, proto_message.id)
    |> Map.put(:initiated?, proto_message.initiated)
  end
end

Summary

Types

t()

All the types that implement this protocol.

Functions

from_proto_message(message, term)

Given the initial message, and the decoded Protobuf struct, returns the decoded term.

proto_module(message)

Returns the module name of the Protobuf struct.

to_proto_message(message)

Given a struct, returns a Protobuf struct.

Types

t()

@type t() :: term()

All the types that implement this protocol.

Functions

from_proto_message(message, term)

Given the initial message, and the decoded Protobuf struct, returns the decoded term.

The default implementation returns the decoded term itself because implicitly expects the initial message to be a Protobuf struct. No need to map the decoded term to the initial message.

proto_module(message)

Returns the module name of the Protobuf struct.

The default implementation returns the struct name of the message because implicitly expects the struct to be a Protobuf struct. No need to map the struct to the message.

to_proto_message(message)

Given a struct, returns a Protobuf struct.

The default implementation returns the message itself because implicitly expects the struct to be a Protobuf struct. No need to map the struct to the message.