Scheduling Tasks

Stonefield Query has had a reports scheduler for several years. We simply use the Windows Task Scheduler to run Stonefield Query, with the name of the report to run and where to send the output as parameters, at the desired schedule. To communicate with the Task Scheduler, we use the freeware TaskScheduler.DLL, written by Mark Pryor. It doesn't look like the site I downloaded it from is available anymore, so it's in the download mentioned later.

However, after upgrading to Windows Vista, I discovered the scheduler didn't work. In researching this issue, I discovered that Vista includes Task Scheduler 2.0, while the DLL was written to support Task Scheduler 1.0, which has a completely different interface. So, back to the drawing board.

Fortunately, the MSDN documentation on Task Scheduler 2.0 has tons of detail and several examples in VBScript, which are easily converted to VFP. Because I still need to use Task Scheduler 1.0 with XP and earlier systems, I decided to create a TaskScheduler base class and XP and Vista subclasses of it.

I won't show the code for these classes here because it's fairly lengthy (you can download it from the Technical Papers page of my Web site), but here are some examples of how easy they are to use to schedule tasks. These examples run on Vista; use XPTaskScheduler instead for Windows XP or earlier.

* Create a task that runs at 3:00 AM every day.

loSchedule = createobject('VistaTaskScheduler')
with loSchedule
  .TaskName      = 'My Task Name'
  .UserName      = 'Your Windows UserName'
  .Password      = 'Your Windows Password'
  .StartTime     = {^2007-04-26 03:00:00}
  .EXEName       = 'Full path to EXE'
  .EXEParameters = 'Any parameters to pass'
  .ScheduleType  = 1 && daily
  if not .CreateTask()
    messagebox(.ErrorMessage)
  endif not .CreateTask()
endwith

* Create a weekly task that runs at 3:00 AM Tues, Thurs, and Sat
* of every second week.

loSchedule = createobject('VistaTaskScheduler')
with loSchedule
  .TaskName      = 'My Task Name'
  .UserName      = 'Your Windows UserName'
  .Password      = 'Your Windows Password'
  .StartTime     = {^2007-04-26 03:00:00}
  .EXEName       = 'Full path to EXE'
  .EXEParameters = 'Any parameters to pass'
  .ScheduleType  = 2 && weekly
  .Interval      = 2
  store .T. to .DaysOfWeek[3], .DaysOfWeek[5], .DaysOfWeek[7]
  if not .CreateTask()
    messagebox(.ErrorMessage)
  endif not .CreateTask()
endwith

* Create a monthly task that runs at 3:00 AM on the 1st and 15th
* of every month.

loSchedule = createobject('VistaTaskScheduler')
with loSchedule
  .TaskName      = 'My Task Name'
  .UserName      = 'Your Windows UserName'
  .Password      = 'Your Windows Password'
  .StartTime     = {^2007-04-26 03:00:00}
  .EXEName       = 'Full path to EXE'
  .EXEParameters = 'Any parameters to pass'
  .ScheduleType  = 3
  store .T. to .DaysOfMonth[1], .DaysOfMonth[15]
  .MonthsOfYear = .T. && initialize all 12 elements of array to .T.
  if not .CreateTask()
    messagebox(.ErrorMessage)
  endif not .CreateTask()
endwith