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VBA for Task Dependencies

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Say a task has two dependency chains associated with it. For instance, suppose one chain goes from task 2 to 4 to 8 to 10 and another chain goes from 2 to 5 to 9. When looping through the task dependencies object recursively, is there some way to detect when the links shift from one chain to another?

I'm using the approach outlined by Rod Gill on pp 335-6 of his fine book. (See below.) The approach does not seem to differentiate between the two chains--Flag20 is marked for both chains at the same time. I need to process one chain, then the other.

Public Sub DepSucc(Tsk As Task)
Dim Dep As TaskDependency

If Tsk.Flag20 = False Then
    Tsk.Flag20 = True
    For Each Dep In Tsk.TaskDependencies
        If (Dep.To.ID <> Tsk.ID) Then
            DepSucc Dep.To
        End If
    Next
End If

End Sub

RobVV

Tuesday, April 8, 2014 11:20 PM

Answers

The first time you loop through all dependencies for the selected task you need to set in a variable what field to update. So you need a wrapper sub around what you have, something like (not tested)

Public Sub DepFirstSucc(Tsk As Task)
Dim Dep As TaskDependency
Dim Flagnum as Long

FlagNum = FlagNum
If Tsk.GetField(FlagNum) = False Then
    Tsk.SetField FlagNum, True
    For Each Dep In Tsk.TaskDependencies
        If (Dep.To.ID <> Tsk.ID) Then
            DepSucc Dep.To, FlagNum
            FlagNum = FlagNum - 1
        End If
    Next
End If

End Sub

Public Sub DepSucc(Tsk As Task, FlagNum as Long)
Dim Dep As TaskDependency

FlagNum = FlagNum
If Tsk.GetField(FlagNum) = False Then
    Tsk.SetField FlagNum, True
    For Each Dep In Tsk.TaskDependencies
        If (Dep.To.ID <> Tsk.ID) Then
            DepSucc Dep.To, Flagnum
        End If
    Next
End If

End Sub

Note Flag20 is last flag, so I decrement the Flagnum field to use Flgag19 etc.

Rod Gill
Author of the one and only Project VBA Book
www.project-systems.co.nz

Marked as answer by RobVV Thursday, April 10, 2014 1:41 PM

Wednesday, April 9, 2014 9:13 PM

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Talk of the devil!

What are you trying to achieve? What was the originally selected task? If it was 2, then all the tasks should end up flagged as they are all successors of task 2
Rod Gill
Author of the one and only Project VBA Book
www.project-systems.co.nz

Wednesday, April 9, 2014 8:03 AM
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Hi, Rod. It's great to have a response from the maestro. What I'm trying to do is identify each dependency chain individually so that I can do a calculation on each chain. Starting at task 2, there are two chains in the example: 2-4-8-10 and 2-5-9. When I use the recursive code, Flag20 is marked for 2, 4, 8, 10, 5, and then 9. I was hoping that there was some way within the recursive loop to determine when the first chain stopped and the second chain started. If so, I could take a different action, e.g., mark Flag21, for the second chain.
RobVV

Wednesday, April 9, 2014 1:57 PM