ProSol.Messaging

Implements a message broker with ability to build a pipeline of listeners.

API

The project contains an API for the Observer pattern: IPublisher, ISubscriber, and PipelinePublisher.

• The IPublisher interface is aimed to provide a layer of absctraction to the client.
• The ISubscriber interface decalres a subscription contract with chained calls support via NextDelegate.
  • NextDelegate: is a mandatory delegate to trigger if current subscriber wants to bypass a message to next subscriber.
• PipelinePublisher: a ready-to-use implementation for chained subscriptions.

Demo

Let's see how works in a console app, by making a publisher for strings, which addresses the message to the StringListener, but there is a StringLimitListener between them.

So, the StringLimitListener will drop the message longer than "Please" string:

using ProSol.Messaging; var maxLength = "Please".Length + 1; var broker = new MessageBroker<string>(); // Set up a chain. broker.Subscribe(new StringLimitListener(maxLength)); broker.Subscribe(new StringListener()); // Push some messages. broker.Publish("Please"); broker.Publish("STOP"); broker.Publish("The planet"); // OUTPUT: // Please // STOP // Clean up. broker.Complete(); public class StringListener : ISubscriber<string> { public void OnCompleted() { } public void OnNext(string message, NextDelegate next) { Console.WriteLine(message); if (message != "STOP") { next(); } } } public class StringLimitListener(int limit) : ISubscriber<string> { private readonly int limit = limit; public void OnCompleted() { } public void OnNext(string message, NextDelegate next) { if (message.Length < limit) { next(); } } }