Otc.Messaging

Otc.Messaging goal is to abstract complex aspects of working with Messaging Systems by providing a simplified and easy to use API for .NET Standards 2.0.

Currently it supports only RabbitMQ as backend. Otc.Messaging.RabbitMQ was built on top of RabbitMQ.Client and provides opinionated implementation of some common patterns.

Quickstart

Installation

Recommended to install it from NuGet. It's spplited into two packages:

• Otc.Messaging.Abstractions - Interfaces, exception types, all you need to use it, except implementation;
• Otc.Messaging.RabbitMQ - RabbitMQ implementation.

** Curretly only pre-release packages are available

Configuration

At startup, add IMessaging to your service collection by calling AddRabbitMQ extension method for IServiceCollection (AddRabbitMQ lives at Otc.Messaging.RabbitMQ assembly):

services.AddRabbitMQ(new RabbitMQConfiguration
{ 
    Hosts = new List<string> { "localhost" },
    Port = 5672,
    User = "guest",
    Password = "guest"
});

AddRabbitMQ will register RabbitMQMessaging implementation (from Otc.Messaging.RabbitMQ assembly) for IMessaging interface (from Otc.Messaging.Abstractions assembly) as singleton lifetime.

Basic Usage

Publish to a topic (exchange)

IMessaging bus = ... // get messaging bus from service provider (using dependency injection)

string message = "Hello world!";
byte[] messageBytes = Encoding.UTF8.GetBytes(message);

// Create a publisher
IPublisher publisher = bus.CreatePublisher();

// Publish "Hello world!" string to a topic named "TopicName"
publisher.Publish(messageBytes, "TopicName");

Subscribe to queue(s)

Subscribe to queue(s) and start consuming:

IMessaging bus = ... // taken from service provider

// Subscribe to "QueueName1" and "QueueName2" queues
ISubscription subscription = bus.Subscribe((message, messageContext) =>
{
    // do something useful with the message
}
, "QueueName1", "QueueName2");

// Start consuming messages
subscription.Start();

// Consuming messages ...
// Thread.Sleep(10000);

// To stop consuming messages
subscription.Stop();

Typed Messages

You can publish and consume typed object messages along with the implementation package of choice.

Install additional NuGet packages so you will get some extensions to IMessaging interface:

• Otc.Messaging.Typed.Abstractions - Interfaces and Extensions you need to use typed messages;
• Otc.Messaging.Typed - Default serializer implementation and registration.

** Curretly only pre-release packages are available

At startup, add a call to AddTypedMessaging extension method for IServiceCollection (AddTypedMessaging lives at Otc.Messaging.Typed assembly):

Publish to a topic

IMessaging bus = ... // get messaging bus from service provider (using dependency injection)

public class MyMessage
{
    public string Text { get; set; }
}

var message = new MyMessage { Text = "Hello world!" };

// Create a publisher for MyMessage
IPublisher publisher = bus.CreatePublisher();

// Publish MyMessage to a topic named "TopicName"
publisher.Publish(message, "TopicName");

Subscribe to queue(s)

Subscribe to queue(s) and start consuming:

IMessaging bus = ... // taken from service provider

// Subscribe to "QueueName1" and "QueueName2" queues
ISubscription subscription = bus.Subscribe<MyMessage>((message, messageContext) =>
{
    // do something useful with MyMessage
}
, "QueueName1", "QueueName2");

// Start consuming messages
subscription.Start();

// Consuming messages ...
// Thread.Sleep(10000);

// To stop consuming messages
subscription.Stop();

Subscriber Hosted Worker

TODO: write about it.