Scheduled tasks using Orchard CMS - model-view-controller

Question

I need to create a scheduled task using Orchard CMS.
I have a service method (let's say it loads some data from external sources), and I need to execute it every day at 8:00 AM.
I figured out I have to use IScheduledTaskHandler and IScheduledTaskManager... Does anyone know how to solve this problem? Some sample code will be appreciated.

Answer 1

In your IScheduledTaskHandler, you have to implement Process to provide your task implementation (I Advise you to put your implementation in another service class), and you have to register your task in the task manager. Once in the Handler constructor to register the first task, and then in the process implementation, to ensure that once a task was executed, the next one is scheduled.
Here is a sample:
public class MyTaskHandler : IScheduledTaskHandler
{
private const string TaskType = "MyTaskUniqueID";
private readonly IScheduledTaskManager _taskManager;
public ILogger Logger { get; set; }
public MyTaskHandler(IScheduledTaskManager taskManager)
{
_taskManager = taskManager;
Logger = NullLogger.Instance;
try
{
DateTime firstDate = //Set your first task date (utc).
ScheduleNextTask(firstDate);
}
catch(Exception e)
{
this.Logger.Error(e,e.Message);
}
}
public void Process(ScheduledTaskContext context)
{
if (context.Task.TaskType == TaskType)
{
try
{
//Do work (calling an IService for instance)
}
catch (Exception e)
{
this.Logger.Error(e, e.Message);
}
finally
{
DateTime nextTaskDate = //Your next date (utc).
this.ScheduleNextTask(nextTaskDate);
}
}
}
private void ScheduleNextTask(DateTime date)
{
if (date > DateTime.UtcNow )
{
var tasks = this._taskManager.GetTasks(TaskType);
if (tasks == null || tasks.Count() == 0)
this._taskManager.CreateTask(TaskType, date, null);
}
}
}

Answer 2

You should do the first scheduling with an implementation of IOrchardShellEvents rather than in the task constructor to avoid adding multiple tasks.
Here is an abstract DailyTaskHandler class you can implement :
Usage
public class MyTaskHandler : DailyTaskHandler {
private readonly IMyService _myService;
public MyTaskHandler(IMyService myService,
IDailyTasksScheduler dailyTasksScheduler) : base(dailyTasksScheduler) {
_myService = myService;
}
public override int Hour => base.Hour; // you can override default hour
public override void Process() => _myService.DoStuff();
}
Abstract daily task handler and scheduler
public abstract class DailyTaskHandler : IDailyTaskHandler, IScheduledTaskHandler {
private readonly IDailyTasksScheduler _dailyTasksScheduler;
protected DailyTaskHandler(IDailyTasksScheduler dailyTasksScheduler) {
_dailyTasksScheduler = dailyTasksScheduler;
Logger = NullLogger.Instance;
TaskType = GetType().FullName;
}
public ILogger Logger { get; set; }
public virtual int Hour { get; } = 1; // default scheduled hour of the day
public string TaskType { get; }
public void Process(ScheduledTaskContext context) {
if (context.Task.TaskType == TaskType) {
Logger.Information($"Process task: {TaskType}");
try {
Process();
}
catch (Exception e) {
Logger.Error(e, e.Message);
}
finally {
_dailyTasksScheduler.Schedule(this);
}
}
}
public abstract void Process();
}
public class DailyTasksStarter : IOrchardShellEvents {
private readonly IEnumerable<IDailyTaskHandler> _dailyTaskHandlers;
private readonly IDailyTasksScheduler _dailyTasksScheduler;
public DailyTasksStarter(
IEnumerable<IDailyTaskHandler> dailyTaskHandlers,
IDailyTasksScheduler dailyTasksScheduler) {
_dailyTaskHandlers = dailyTaskHandlers;
_dailyTasksScheduler = dailyTasksScheduler;
}
public void Activated() => _dailyTasksScheduler.Schedule(_dailyTaskHandlers);
public void Terminating() { }
}
public class DailyTasksScheduler : IDailyTasksScheduler {
private readonly IScheduledTaskManager _scheduledTaskManager;
public DailyTasksScheduler(IScheduledTaskManager scheduledTaskManager) {
_scheduledTaskManager = scheduledTaskManager;
}
public void Schedule(IDailyTaskHandler dailyTaskHandler) => Schedule(new IDailyTaskHandler[] { dailyTaskHandler });
public void Schedule(IEnumerable<IDailyTaskHandler> dailyTaskHandlers) {
DateTime nextDay = DateTime.UtcNow.AddDays(1);
foreach (var dailyTaskHandler in dailyTaskHandlers) {
DateTime nextTaskDate = new DateTime(nextDay.Year, nextDay.Month, nextDay.Day, dailyTaskHandler.Hour, 0, 0, DateTimeKind.Utc);
if (nextTaskDate > DateTime.UtcNow && _scheduledTaskManager.GetTasks(dailyTaskHandler.TaskType)?.Any() != true) {
_scheduledTaskManager.CreateTask(dailyTaskHandler.TaskType, nextTaskDate, null);
}
}
}
}
public interface IDailyTaskHandler : IDependency {
int Hour { get; }
string TaskType { get; }
}
public interface IDailyTasksScheduler : IDependency {
void Schedule(IDailyTaskHandler dailyTaskHandler);
void Schedule(IEnumerable<IDailyTaskHandler> dailyTaskHandlers);
}
You can avoid using a task scheduler class by having the schedule method and the IOrchardShellEvents implementation on your task handler class.