FluentScheduler

Automated job scheduler with fluent interface.

Usage
Using it with ASP.NET
Using it with .NET Core
Dependency Injection
Unexpected exceptions
Daylight Saving Time
Weekly jobs
Concurrent jobs
Major changes
Contributing

Usage

The job configuration is handled in a Registry class. A job is either an Action or a class that inherits IJob:

using FluentScheduler;

public class MyRegistry : Registry
{
    public MyRegistry()
    {
        // Schedule an IJob to run at an interval
        Schedule<MyJob>().ToRunNow().AndEvery(2).Seconds();

        // Schedule an IJob to run once, delayed by a specific time interval
        Schedule<MyJob>().ToRunOnceIn(5).Seconds();

        // Schedule a simple job to run at a specific time
        Schedule(() => Console.WriteLine("It's 9:15 PM now.")).ToRunEvery(1).Days().At(21, 15);

        // Schedule a more complex action to run immediately and on an monthly interval
        Schedule<MyComplexJob>().ToRunNow().AndEvery(1).Months().OnTheFirst(DayOfWeek.Monday).At(3, 0);
        
        // Schedule multiple jobs to be run in a single schedule
        Schedule<MyJob>().AndThen<MyOtherJob>().ToRunNow().AndEvery(5).Minutes();
    }
}

You can also use the Registry class directly (instead of inheriting it):

var registry = new Registry();
registry.Schedule<MyJob>().ToRunNow().AndEvery(2).Seconds();
registry.Schedule<MyJob>().ToRunOnceIn(5).Seconds();
registry.Schedule(() => Console.WriteLine("It's 9:15 PM now.")).ToRunEvery(1).Days().At(21, 15);
registry.Schedule<MyComplexJob>().ToRunNow().AndEvery(1).Months().OnTheFirst(DayOfWeek.Monday).At(3, 0);
registry.Schedule<MyJob>().AndThen<MyOtherJob>().ToRunNow().AndEvery(5).Minutes();

To check all possible options of scheduling you can use IntelliSense on the go or check this daunting call graph (click to enlarge):

With the registry ready you then need to initialize the JobManager. This is usually done as soon as your application is loaded (in the Application_Start method of a web application for example):

protected void Application_Start()
{
    JobManager.Initialize(new MyRegistry()); 
}

It's also possible to schedule jobs after initialization:

JobManager.AddJob(() => Console.WriteLine("Late job!"), (s) => s.ToRunEvery(5).Seconds());

Using it with ASP.NET

When using it with ASP.NET consider implementing IRegisteredObject in your job and registering it itself on HostingEnvironment (here's a great explanation on it), like:

public class SampleJob : IJob, IRegisteredObject
{
    private readonly object _lock = new object();

    private bool _shuttingDown;

    public SampleJob()
    {
        // Register this job with the hosting environment.
        // Allows for a more graceful stop of the job, in the case of IIS shutting down.
        HostingEnvironment.RegisterObject(this);
    }

    public void Execute()
    {
        lock (_lock)
        {
            if (_shuttingDown)
                return;

            // Do work, son!
        }
    }

    public void Stop(bool immediate)
    {
        // Locking here will wait for the lock in Execute to be released until this code can continue.
        lock (_lock)
        {
            _shuttingDown = true;
        }

        HostingEnvironment.UnregisterObject(this);
    }
}

Using it with .NET Core

FluentScheduler supports .NET Core, just add the dependency to project.json and run dotnet restore.

  "dependencies": {
    "FluentScheduler": "5.0.0"
  }

There's no support for ASP.NET Core at the moment (#94).

Dependency Injection

FluentScheduler makes it easy to use your IoC tool of choice to create job instances. Simply implement IJobFactory.

An example using StructureMap:

using FluentScheduler;
using StructureMap;

public class StructureMapJobFactory : IJobFactory
{
    public IJob GetJobInstance<T>() where T : IJob
    {
        return ObjectFactory.Container.GetInstance<T>();
    }
}

public class MyRegistry : Registry
{
    public MyRegistry()
    {
        // Schedule an IJob to run at an interval
        Schedule<MyJob>().ToRunNow().AndEvery(2).Seconds();
    }
}

protected void Application_Start()
{
    JobManager.JobFactory = new StructureMapJobFactory();
    JobManager.Initialize(new MyRegistry()); 
}

Unexpected exceptions

To observe unhandled exceptions from your scheduled jobs, you will need to hook the JobException event on JobManager. That event will give you access to the underlying System.Threading.Tasks.Task and thrown exception details.

JobManager.JobException += (info) => Log.Fatal("An error just happened with a scheduled job: " + info.Exception);

Daylight Saving Time

Unfortunately, not unlike many schedulers, there is no Daylight Saving Time support yet.

If you are worried about your jobs not running or running twice due to that, the suggestion is to avoid troublesome time ranges or just UseUtcTime() in your registry.

Weekly jobs

Let's suppose it's 10:00 of a Monday morning and you want to start a job that runs every Monday at 14:00. Should the first run of your job be today or only on the next week Monday?

If you want the former (not waiting for a whole week):

// Every "zero" weeks
Schedule<MyJob>().ToRunEvery(0).Weeks().On(DayOfWeek.Monday).At(14, 0);

Or if you want the latter (making sure that at least one week has passed):

// Every "one" weeks
Schedule<MyJob>().ToRunEvery(1).Weeks().On(DayOfWeek.Monday).At(14, 0);

Concurrent jobs

By default, the library allows a schedule to run in parallel with a previously triggered execution of the same schedule.

If you don't want such behaviour you can set a specific schedule as non-reentrant:

public class MyRegistry : Registry
{
    Schedule<MyJob>().NonReentrant().ToRunEvery(2).Seconds();
}

Or you can set it on all schedules:

public class MyRegistry : Registry
{
    NonReentrantAsDefault();
    Schedule<MyJob>().ToRunEvery(2).Seconds();
}

Major changes

Version 4 to 5

AndEvery only starts after ToRunOnceAt has been fired;
Simplified event data types and signatures.

Version 3 to 4

Renamed ITask, TaskManager and ITaskFactory to IJob, JobManager and IJobFactory.

Contributing

Feel free to open an issue or submit a pull request.

When sending a patch remember to Run All Tests (Ctrl + R, A) and Run Code Analysis on Solution (Alt + F11) if possible. And, of course, be consistent with the existing code!

mdissel / FluentScheduler