We are using DevForce 2010 v6.0.6.0, MVVM and Prism.

One of our modules is handling alarms, which are entries in one of our database-tables.

Is it possible to let the entitymodel push events to our modules if a new entry has arrived in our database-tables.

Is there any samplecode/documentation about this?

Thank you smi-mark!

Great example.

But I have run into problems.

I have added all references and assemblies, as ordered.

My client side code looks something like this:

public void SubscribeAlarmEvents()

{

m_token = new Guid();

p_manager.RegisterCallback(

                "ServerModelC2Net.AlarmWatcher, ServerModelC2Net",

                "NewAlarmService",

                AlarmPushCallback,

                m_token);

}

private void AlarmPushCallback(SubscriptionOperation op)

{

MessageBox.Show("New Alarm!!!");

}

And my server side something like this:

[AllowRpc]

public static void NewAlarmService(Guid servicekey, INotificationManager notificationManager, EntityManager entityManager)

{

m_serviceKey = servicekey;

m_notificationManager = notificationManager;

m_entityManager = new C2NetDomainModelEntityManager(entityManager);

TraceFns.WriteLine("AlarmWatcher started");

while (true)

{

CheckForNewAlarms();

//sleep for 60 seconds

Thread.Sleep(1000*60*1);

}

TraceFns.WriteLine("AlarmWatcher stopping");

}

private static void CheckForNewAlarms()

{

var newAlarms = m_entityManager.EntAlarms.Where(e => e.p_timestamp >= m_lastCheckTime).ToList();

m_lastCheckTime = DateTime.SpecifyKind(DateTime.Now, DateTimeKind.Utc);

if (newAlarms.Count()==0) return;

m_notificationManager.Send(m_serviceKey, newAlarms.Count());

}

These are some of the entries in the debuglog:

After I insert a new alarm in the database, I get the “Removing subscriber after error...” in my debuglog.

I also know that

m_notificationManager.Send(m_serviceKey, newAlarms.Count());

is executed.

What is wrong?

Yes I have also tried with GetSubscribers – same behavior and error.

I should note that the push notification example from Ideablade runs fine.

Here is my webconfig:

<?xml version="1.0"?>

<configuration>

       <configSections>

             <section name="ideablade.configuration" type="IdeaBlade.Core.Configuration.IdeaBladeSection, IdeaBlade.Core"/>

       </configSections>

       <ideablade.configuration version="6.00" xmlns="http://schemas.ideablade.com/2010/IdeaBladeConfig">

             <objectServer>

                    <serverSettings loginManagerRequired="true"/>

             </objectServer>

    <!-- Enable the Push service -->

    <notificationService enabled="true" />

             <!--    <probeAssemblyNames>

       <probeAssemblyName name="C2Net.CommonClasses"/>

       <probeAssemblyName name="C2NetServer"/>

       <probeAssemblyName name="ServerModelC2Net"/>

     </probeAssemblyNames> -->

             <logging logFile="log\DebugLog.xml"/>

       </ideablade.configuration>

       <system.serviceModel>

             <!-- Set this to true to allow use of ASP.NET security features. -->

             <serviceHostingEnvironment aspNetCompatibilityEnabled="false"/>

       </system.serviceModel>

       <system.web>

             <compilation debug="true" targetFramework="4.0">

                    <assemblies>

                           <add assembly="System.Data.Entity, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>

                    </assemblies>

             </compilation>

             <pages controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID"/>

       </system.web>

       <!--  The system.webServer section is required when hosting a Silverlight application under Internet

        Information Services 7.0.  It is not necessary for previous version of IIS.

    -->

       <connectionStrings>

             <add name="..." connectionString="...;" providerName="System.Data.EntityClient"/>

       </connectionStrings>

</configuration>

I have changed my service a little bit, to simplify things. Now it sends an event periodically:

[AllowRpc]

public static void NewAlarmService(Guid servicekey, INotificationManager notificationManager, EntityManager entityManager)

{

m_serviceKey = servicekey;

m_notificationManager = notificationManager;

m_entityManager = new C2NetDomainModelEntityManager(entityManager);

TraceFns.WriteLine("AlarmWatcher started");

while (true)

{

TraceFns.WriteLine("Sending alarm event");

m_notificationManager.Send(m_serviceKey, new AlarmCount(1));

TraceFns.WriteLine("Alarm event sent");

//sleep for 60 seconds

Thread.Sleep(1000*60*1);

}

TraceFns.WriteLine("AlarmWatcher stopping");

}

When I run this, I get the first event, but not the rest of the events.

Here is my debugLog - maybe the last entry provides a clue?

I changed the sleep time in LongRunningProcedure in Ideablades example like this:

private static void Step1() {

// Assume some logic is performed that represents 20% of the total workload.

Thread.Sleep(1000 * 5);

__notificationManager.Send(__serviceKey, new LongRunningInfo("The LongRunningProcedure is 20% done.", 20));

}

private static void Step2() {

// Assume some logic is performed that represents 50% of the total workload.

Thread.Sleep(1000 * 30);

__notificationManager.Send(__serviceKey, new LongRunningInfo("The LongRunningProcedure is 50% done.", 50));

}

private static void Step3() {

// Assume some logic is performed that represents 90% of the total workload.

Thread.Sleep(1000 * 40);

__notificationManager.Send(__serviceKey, new LongRunningInfo("The LongRunningProcedure is 90% done.", 90));

}

private static void Step4() {

// Assume some logic is performed that represents 100% of the total workload.

Thread.Sleep(1000 * 5);

__notificationManager.Send(__serviceKey, new LongRunningInfo("The LongRunningProcedure has completed.", 100));

}

And I got the same error in the debuglog.

If I change my service to send events every 5 second – then it works fine!

Further I have found out that if the frequency, where the service is sending events is somewhere between 15-20 seconds it will work fine. If it is above 15+ seconds, a timeout error will appear in the debuglog.

Is this some inactive timeout?

Is it possible to change it?