Try It Yourself: Create a Custom Timer Job

Let’s create a new timer job to add a new announcement to the Announcements list of the top level site in a site collection. We will schedule the job to run every 5 minutes and populate the Announcements list with new announcements in the format shown in Figure 7.15.

Figure 7.15. Creating announcements with a custom timer job

1. Fire up Visual Studio and create a new empty SharePoint project.

2. Add a new class called TimerJobDemo in the project.

3. To create a timer job definition, you inherit the TimerJobDemo class from the SPJobDefinition class and override its Execute method to specify a set of actions to perform when the job is executed, as demonstrated in the following code:

public override void Execute(Guid targetInstanceId)
{
    // Get reference to web application
    SPWebApplication webApp = this.Parent as SPWebApplication;

    if (webApp != null && webApp.Sites.Count != 0)
    {
        // Get reference to root web of the
        // first site collection in the web application
        SPWeb web = webApp.Sites[0].RootWeb;

        // Get reference to the announcements list
        SPList announcements = web.Lists["Announcements"];

        // App new announcement to the list
        SPListItem newAnnouncement = announcements.AddItem();
        newAnnouncement["Title"] =
       "New Announcement, creation time: " +
        DateTime.Now.ToShortTimeString();
        newAnnouncement.Update();
    }
}

In the preceding code, we get a reference to the root web of the first site collection in the web application and add a new announcement to the same.

4. Further, the job definition should be associated either with a web application or with a service. In our case, we would associate it with a web application. This requires creating a constructor to accept the SPWebApplication object as a parameter, as demonstrated in the following code snippet.

public TimerJobDemo(SPWebApplication webApp)
    : base("TimerJobDemo", webApp, null, SPJobLockType.None)
{
}

5. To deploy this timer job, we create a Web Application scoped feature and add event receivers to handle the FeatureActivated and FeatureDeactivating events. In the FeatureActivated event, we instantiate the TimeJobDemo class and create a schedule to run it after 5 minutes at any time between 0th and 59th second of the minute, as shown in the following code:

public override void FeatureActivated(SPFeatureReceiverProperties properties)
{
    SPWebApplication webApp = properties.Feature.Parent as
SPWebApplication;

    // Create the timer job
    TimerJobDemo timerJob = new TimerJobDemo(webApp);

    // Schedule it to run after 5 minutes at any time
    // between 0th and 59th second of the minute
    SPMinuteSchedule schedule = new SPMinuteSchedule();
    schedule.BeginSecond = 0;
    schedule.EndSecond = 59;
    schedule.Interval = 5;
    timerJob.Schedule = schedule;
    timerJob.Update();
}

6. In the FeatureDeactivating event, we loop through the web application’s job definitions and delete the timer job from the same, as shown in the following code:

public override void FeatureDeactivating(SPFeatureReceiverProperties properties)
{
    // Delete the timer job
    SPWebApplication webApp = properties.Feature.Parent as
SPWebApplication;
    foreach (SPJobDefinition job in webApp.JobDefinitions)
    {
        if (job.Name == "TimerJobDemo")
        {
            job.Delete();
            break;
        }
    }
}

Figure 7.16. Setting the Activate on Default property to false

7. Next deploy the feature, navigate to Central Administration, and activate the TimerJobDemo feature for your web application. Once the feature is activated and the timer job starts running, you should see the timer job in the Job Definitions screen for your web application in Central Administration, as shown in Figure 7.17.

Figure 7.17. Examining the TimerJobDemo’s job definition in Central Administration

8. Click the timer job and further verify that the job has been scheduled to run after an interval of 5 minutes, as shown in Figure 7.18.

Figure 7.18. Verifying the TimerJobDemo’s schedule