Standardized messaging with System.Text.Json serialization.
Preform serialization/deserialization of messages such that receiving services can be agnostic with respect to message type.
Install the JsonEnvelopes NuGet Package (e.g. version 2.0.1).
dotnet add package JsonEnvelopes --version 2.0.1
Any class with a default constructor can be wrapped with Envelope<T>, e.g. the command CastFireball.
var command = new CastFireball();
var envelope = new Envelope<CastFireball>(command);
Serialize the envelope by calling JsonSerializer.Serialize<Envelope> (System.Text.Json namespace) and passing it an Envelope<T> instance. Note that the generic argument passed to Serialize is of type Envelope not of type Envelope<T>. This triggers the use of EnvelopeJsonConverter's customized serialization operations (i.e. Read/Write);
var json = JsonSerializer.Serialize<Envelope>(envelope);
Deserialize json for an Envelope by calling JsonSerializer.Deserialize<Envelope>. Again note the generic argument is of type Envelope which engages EnvelopeJsonConverter.
var receivedEnvelope = JsonSerializer.Deserialize<Envelope>(json);
The envelope's ContentType provides the AssemblyQualifiedName string of the content's type (e.g. "JsonEnvelopes.Example.Commands.CastFireball, JsonEnvelopes.Example, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null").
var assemblyQualifiedName = receivedEnvelope.ContentType;
The envelope's GetContent method returns an object which is of the type provided by the ContentType property. Continuing the example the variable success will be true in the following.
var contentType = receivedEnvelope.GetContent().GetType();
var success = contentType == typeof(CastFireball);
See the project JsonEnvelopes.Example for examples of JsonEnvelopes message handling with Dependency Injection and additionally with MediatR.
The methodology used in JsonEnvelopes was heavily inspired by the work of the extraordinary developer Jonathan Berube. My thanks to him.