It has been a long time (10 months) since I worked with the Ninject MessageBroker and a couple things have changed since my last post. In the old version you had to connect the MessageBroker as a kernel component by hand. Since then the extension environment has been flushed out a lot more. Now you can register the MessageBrokerModule when constructing your kernel object.
using System;
using System.Diagnostics;
using System.Net;
using System.Text.RegularExpressions;
using Ninject.Core;
using Ninject.Extensions.MessageBroker;
namespace NinjectMessageBroker
{
internal class Program
{
private static void Main()
{
// Intialize our injection kernel adding message broker functionality.
using (var kernel = new StandardKernel(new[] { new MessageBrokerModule() }))
{
// Get the event publisher. It reads the current time and fires an event
var pub = kernel.Get<TimeReader>();
Debug.Assert(pub != null);
// Get the subscriber, it waits to get the current time and writes it to stdout
var sub = kernel.Get<TimeWriter>();
Debug.Assert(sub != null);
// Verify that they were wired together
Debug.Assert(pub.HasListeners);
Debug.Assert(sub.LastMessage == null);
// Get the current time. It should automatically let the TimeWriter know
// without either of them ever knowing of one another.
pub.GetCurrentTime();
// Wait to exit.
Console.ReadLine();
}
}
}
internal class TimeWriter
{
public string LastMessage { get; set; }
[Subscribe("message://Time/MessageReceived")]
public void OnMessageReceived(object sender, EventArgs<string> args)
{
LastMessage = args.EventData;
Console.WriteLine(LastMessage);
}
}
internal class TimeReader
{
public bool HasListeners
{
get { return (MessageReceived != null); }
}
[Publish("message://Time/MessageReceived")]
public event EventHandler<EventArgs<string>> MessageReceived;
/// <summary>
/// Gets the current time and updates all subscribers.
/// </summary>
public virtual void GetCurrentTime()
{
string text = GetWebPage();
var regex = new Regex(@"\d\d:\d\d:\d\d");
MatchCollection matches = regex.Matches(text);
string time = ((matches.Count == 2) ? matches[1] : matches[0]).Value;
SendMessage(time);
}
/// <summary>
/// Gets the contents of a web page as a string.
/// </summary>
/// <returns></returns>
private static string GetWebPage()
{
const string url = "http://www.time.gov/timezone.cgi?Eastern/d/-5";
var webClient = new WebClient();
return webClient.DownloadString(url);
}
/// <summary>
/// Sends the message to all subscribers in a threadsafe manner.
/// </summary>
/// <param name="message">The message.</param>
public void SendMessage(string message)
{
EventHandler<EventArgs<string>> messageReceived = MessageReceived;
if (messageReceived != null)
{
messageReceived(this, new EventArgs<string>(message));
}
}
}
public class EventArgs<TData> : EventArgs
{
public new static readonly EventArgs<TData> Empty;
static EventArgs()
{
Empty = new EventArgs<TData>();
}
private EventArgs()
{
}
public EventArgs(TData eventData)
{
EventData = eventData;
}
public TData EventData { get; private set; }
}
}
|
No comments:
Post a Comment