Notification Services—Creating a Notification Services Application and Service

Microsoft .NET Framework, ASP.NET, Visual C# (CSharp, C Sharp, C-Sharp) Developer Training, Visual Studio

Creating a Notification Services Application and Service

This section creates a complete Notification Services application that creates file and email notifications based on changes in a stock price. For the purpose of this example, the stock price information is limited to a stock ticker symbol and price. Two subscribers are created—one that is notified by entries in a text file and one that is notified using email. Each of the two users monitors a single stock—ticker symbols ABC and DEF.

This section shows the application that creates the StockWatch Notification Services application and adds two subscribers and a subscription for each. Subsequent sections discuss the different parts of the application in detail.

Follow these steps to create the StockWatch Notification Services application with two subscribers and a subscription for each, start the service, and generate notifications:

1. Create a Visual Studio 2005 C# console application in the C:\PSS2005 directory. Name the project NotificationServices.

2. Add the following references to the project:

• Microsoft.SqlServer.ConnectionInfo
  
• Microsoft.SqlServer.NotificationServices
  
• Microsoft.SqlServer.Smo

3. Replace the code in Program.cs with the code in Example 18-1. This code is explained in detail throughout the rest of this chapter.

Example 18-1. Notification Services example

using System;
using Microsoft.SqlServer.Management.Smo;
using Microsoft.SqlServer.Management.Nmo;
using ns = Microsoft.SqlServer.NotificationServices;
 
class Program
{
  private static Instance nsi;
  private static Application a;
 
  private const string baseDirectoryPath = 
    @"C:\PSS2005\NotificationServices";
  private const string nsServer = "NSServerName";
  private const string serviceUserName = "NSUSerName";
  private const string servicePassword = "NSPassword";
 
  static void Main(string[] args)
  {
    Server server = new Server("(local)");
 
    // create a new instance
    NotificationServices ns = server.NotificationServices;
    nsi = new Instance(ns, "StockWatch");
    CreateDeliveryChannel( );
 
    // create a new application in the StockWatch instance
    a = new Application(nsi, "StockWatchApp");
    a.BaseDirectoryPath = baseDirectoryPath;
    CreateEventClass( );
    CreateSubscriptionClass( );
    CreateNotificationClass( );
    CreateHostedEventProvider( );
    CreateGenerator( );
    CreateDistributor( );
    CreateVacuumSchedule( );
    a.QuantumDuration = new TimeSpan(0, 0, 15);
    a.PerformanceQueryInterval = new TimeSpan(0, 0, 5);
    a.SubscriptionQuantumLimit = 1;
    a.ChronicleQuantumLimit = 1;
    a.VacuumRetentionAge = new TimeSpan(0, 0, 1);
    nsi.Applications.Add(a);
    Console.WriteLine("Added application.");
    nsi.Create( );
    nsi.RegisterLocal(serviceUserName, servicePassword);
    nsi.Enable( );
    Console.WriteLine("Application enabled." + 
      Environment.NewLine);
    CreateSubscriber( );
    CreateSubscription( );
    Console.WriteLine(Environment.NewLine + 
      "Press any key to continue.");
    Console.ReadKey( );
  }
 
  private static void CreateDeliveryChannel( )
  {
    DeliveryChannelArgument dca;
 
    // add file delivery channel
    DeliveryChannel dcFile =
    new DeliveryChannel(nsi, "StockWatchFileDeliveryChannel");
    dcFile.ProtocolName = "File";
    dca = new DeliveryChannelArgument(dcFile, "FileName");
    dca.Value = baseDirectoryPath + 
      @"\Notifications\FileNotifications.txt";
    dcFile.DeliveryChannelArguments.Add(dca);
    nsi.DeliveryChannels.Add(dcFile);
    Console.WriteLine("Added delivery channel: " + dcFile.Name);
 
    //// add email delivery channel
    DeliveryChannel dcEmail =
    new DeliveryChannel(nsi, "StockWatchEmailDeliveryChannel");
    dcEmail.ProtocolName = "SMTP";
    nsi.DeliveryChannels.Add(dcEmail);
    Console.WriteLine("Added delivery channel: " + dcEmail.Name);
  }
 
  private static void CreateEventClass( )
  {
    EventClass ec = new EventClass(a, "StockWatchEvents");
    EventField ef;
    ef = new EventField(ec, "Symbol");
    ef.Type = "nvarchar(6)";
    ec.EventFields.Add(ef);
    ef = new EventField(ec, "Price");
    ef.Type = "float";
    ec.EventFields.Add(ef);
    a.EventClasses.Add(ec);
    Console.WriteLine("Added event class: " + ec.Name);
  }
 
  private static void CreateSubscriptionClass( )
  {
    SubscriptionClass sc = 
      new SubscriptionClass(a, "StockWatchSubscriptions");
    SubscriptionField sf;
    sf = new SubscriptionField(sc, "DeviceName");
    sf.Type = "nvarchar(255)";
    sc.SubscriptionFields.Add(sf);
    sf = new SubscriptionField(sc, "SubscriberLocale");
    sf.Type = "nvarchar(10)";
    sc.SubscriptionFields.Add(sf);
    sf = new SubscriptionField(sc, "Symbol");
    sf.Type = "nvarchar(6)";
    sc.SubscriptionFields.Add(sf);
    sf = new SubscriptionField(sc, "Price");
    sf.Type = "float";
    sc.SubscriptionFields.Add(sf);
    SubscriptionEventRule ser =
    new SubscriptionEventRule(sc, "StockWatchSubscriptionsEventRule");
    ser.Action = @"INSERT INTO StockWatchNotifications (" +
    "SubscriberId, DeviceName, SubscriberLocale, Symbol, Price) " +
    "SELECT s.SubscriberId, s.DeviceName, s.SubscriberLocale, " +
    "e.Symbol, e.Price " +
    "FROM StockWatchEvents e, StockWatchSubscriptions s " +
    "WHERE e.Symbol = s.Symbol";
    ser.EventClassName = "StockWatchEvents";
    sc.SubscriptionEventRules.Add(ser);
    a.SubscriptionClasses.Add(sc);
    Console.WriteLine("Added subscription class: " + sc.Name);
  }
 
  private static void CreateNotificationClass( )
  {
    NotificationClass nc = new NotificationClass
      (a, "StockWatchNotifications");
    NotificationField nf;
    nf = new NotificationField(nc, "Symbol");
    nf.Type = "nvarchar(6)";
    nc.NotificationFields.Add(nf);
    nf = new NotificationField(nc, "Price");
    nf.Type = "float";
    nc.NotificationFields.Add(nf);
    ContentFormatter cf = new ContentFormatter(nc, "XsltFormatter");
    ContentFormatterArgument cfa;
    cfa = new ContentFormatterArgument(cf, "XsltBaseDirectoryPath");
    cfa.Value = a.BaseDirectoryPath + @"\AppDefinition";
    cf.ContentFormatterArguments.Add(cfa);
    cfa = new ContentFormatterArgument(cf, "XsltFileName");
    cfa.Value = "StockWatch.xslt";
    cf.ContentFormatterArguments.Add(cfa);
    nc.ContentFormatter = cf;
    nc.DigestDelivery = true;
    ProtocolField pf;
 
    // add file notification class protocol
    NotificationClassProtocol ncpFile =
    new NotificationClassProtocol(nc, "File");
    pf = new ProtocolField(ncpFile, "Symbol");
    pf.FieldReference = "Symbol";
    ncpFile.ProtocolFields.Add(pf);
    pf = new ProtocolField(ncpFile, "Price");
    pf.FieldReference = "Price";
    ncpFile.ProtocolFields.Add(pf);
    nc.NotificationClassProtocols.Add(ncpFile);
 
    // add email notification class protocol
    NotificationClassProtocol ncpEmail =
    new NotificationClassProtocol(nc, "SMTP");
    pf = new ProtocolField(ncpEmail, "Subject");
    pf.SqlExpression = "'Stock watch: ' + 
      CONVERT(nvarchar(30), GETDATE( ))";
    ncpEmail.ProtocolFields.Add(pf);
    pf = new ProtocolField(ncpEmail, "BodyFormat");
    pf.SqlExpression = "'html'";
    ncpEmail.ProtocolFields.Add(pf);
    pf = new ProtocolField(ncpEmail, "From");
    pf.SqlExpression = "'notification@StockWatchService.com'";
    ncpEmail.ProtocolFields.Add(pf);
    pf = new ProtocolField(ncpEmail, "Priority");
    pf.SqlExpression = "'Normal'";
    ncpEmail.ProtocolFields.Add(pf);
    pf = new ProtocolField(ncpEmail, "To");
    pf.SqlExpression = "DeviceAddress";
    ncpEmail.ProtocolFields.Add(pf);
    nc.NotificationClassProtocols.Add(ncpEmail);
    nc.ExpirationAge = new TimeSpan(1, 0, 0);
    a.NotificationClasses.Add(nc);
    Console.WriteLine("Added notification class: " + nc.Name);
  }
 
  private static void CreateHostedEventProvider( )
  {
    HostedEventProvider hep = 
      new HostedEventProvider(a, "StockWatchHEP");
    hep.ClassName = "FileSystemWatcherProvider";
    hep.SystemName = nsServer;
    HostedEventProviderArgument hepa;
    hepa = new HostedEventProviderArgument(hep, "WatchDirectory");
    hepa.Value = baseDirectoryPath + @"\Events";
    hep.HostedEventProviderArguments.Add(hepa);
    hepa = new HostedEventProviderArgument(hep, "SchemaFile");
    hepa.Value = baseDirectoryPath + 
      @"\AppDefinition\EventsSchema.xsd";
    hep.HostedEventProviderArguments.Add(hepa);
    hepa = new HostedEventProviderArgument(hep, "EventClassName");
    hepa.Value = "StockWatchEvents";
    hep.HostedEventProviderArguments.Add(hepa);
    a.HostedEventProviders.Add(hep);
  }
 
  private static void CreateGenerator( )
  {
    // create a new generator for the application
    Generator g = new Generator(a, "StockWatchGenerator");
    g.SystemName = nsServer;
    a.Generator = g;
    Console.WriteLine("Created generator: " + g.Name);
  }
 
  private static void CreateDistributor( )
  {
    Distributor d = new Distributor(a, "StockWatchDistributor");
    d.SystemName = nsServer;
    d.QuantumDuration = new TimeSpan(0, 0, 15);
    a.Distributors.Add(d);
    Console.WriteLine("Added distributor: " + d.Name);
  }
 
  private static void CreateVacuumSchedule( )
  {
    VacuumSchedule vs = 
      new VacuumSchedule(a, "StockWatchVacuumSchedule");
    vs.StartTime = new TimeSpan(0, 0, 0);
    a.VacuumSchedules.Add(vs);
    Console.WriteLine("Added vacuum schedule: " + vs.Name);
  }
 
  private static void CreateSubscriber( )
  {
    ns.NSInstance swnsi = new ns.NSInstance("StockWatch");
    ns.Subscriber s;
    ns.SubscriberDevice sd;
 
    // create a subscriber
    s = new ns.Subscriber(swnsi);
    s.SubscriberId = @"KristinHamilton";
    s.Add( );
    Console.WriteLine("Added subscriber: " + s.SubscriberId);
 
    // create a file subscriber device
    sd = new ns.SubscriberDevice( );
    sd.Initialize(swnsi);
    sd.DeviceName = "StockWatchSubscriberDevice";
    sd.SubscriberId = "KristinHamilton";
    sd.DeviceTypeName = "File";
    sd.DeviceAddress = "KristinH@StockWatch.ns";
    sd.DeliveryChannelName = "StockWatchFileDeliveryChannel";
    sd.Add( );
    Console.WriteLine("Added subscriber file device.");
 
    // create a subscriber
    s = new ns.Subscriber(swnsi);
    s.SubscriberId = @"TonyHamilton";
    s.Add( );
    Console.WriteLine("Added subscriber: " + s.SubscriberId);
 
    // create an email subscriber device
    sd = new ns.SubscriberDevice( );
    sd.Initialize(swnsi);
    sd.DeviceName = "StockWatchSubscriberDevice";
    sd.SubscriberId = "TonyHamilton";
    sd.DeviceTypeName = "Email";
    sd.DeviceAddress = "TonyH@StockWatchNS.ns";
    sd.DeliveryChannelName = "StockWatchEmailDeliveryChannel";
    sd.Add( );
    Console.WriteLine("Added subscriber email device.");
  }
 
  private static void CreateSubscription( )
  {
    ns.NSInstance swnsi = new ns.NSInstance("StockWatch");
    ns.NSApplication a = 
      new ns.NSApplication(swnsi, "StockWatchApp");
    ns.Subscription s;
 
    // add subscriptions
    s = new ns.Subscription( );
    s.Initialize(a, "StockWatchSubscriptions");
    s.SetFieldValue("DeviceName", "StockWatchSubscriberDevice");
    s.SetFieldValue("SubscriberLocale", "en-us");
    s.SubscriberId = "KristinHamilton";
    s.SetFieldValue("Symbol", "ABC");
    s.SetFieldValue("Price", "0.00");
    s.Add( );
    Console.WriteLine("Added subscription: " + s.SubscriberId);
    s = new ns.Subscription( );
    s.Initialize(a, "StockWatchSubscriptions");
    s.SetFieldValue("DeviceName", "StockWatchSubscriberDevice");
    s.SetFieldValue("SubscriberLocale", "en-us");
    s.SubscriberId = "TonyHamilton";
    s.SetFieldValue("Symbol", "DEF");
    s.SetFieldValue("Price", "0.00");
    s.Add( );
    Console.WriteLine("Added subscription: " + s.SubscriberId);
  }
}