Passing a Function as an Argument

[Ralajer]

I am in the processing of generalizing a lot of my VBA code to remove redundant subroutines and functions to make code maintenance easier. One of the biggest cause for redundancy is having to copy and paste a subroutine because I changed a single function.

Example.

Sub Main()
    ' Code ...
    For Each cell in Range
        ' Code ...
        preParse1(cell.value)
        ' Code ...
    Next cell
End Sub

Calls a standard pre-parser function

Function preParse1(str as String) as String
    ' Many Lines of code
    ' Verify if it needs to be parsed
    parse1(str) 
    ' More code
End Function 

Function parse1(str as String) as String
    ' Code ... 
End Function

Which would have to be rewritten or duplicated to call parse2 instead of parse 1.

Function parse2(str as String) as String
    ' Code ... 
End Function

I would like to rewrite it so that

Sub Main()
    ' Code ...
    For Each cell in Range
        ' Code ...
        preParse(cell.value, parser#)
        ' Code ...
    Next cell
End Sub

and

Function preParse(str as String,  genericFuction as Function) as String
    ' Many Lines of code
    ' Verify if it needs to be parsed
    genericFuction(str) 
    ' More code
End Function

Where genericFunction can be parser1, parser2, etc.

I know that this can be done in other programming languages but I am not too clear how or if this can be done in VBA. I've done some searching but haven't found a clear answer. I hope I've made my problem clear if not let me know.

Thanks

 

[Andrew Poulsom]

Check out the Run method of the Application object in VBA Help.

 

[Ralajer]

Thanks very straight forward. This isn't the first that run turned out to be a simple solution.

 

[Ralajer]

Just to follow up with code that works for me.

Sub Main()
    ' Code ...
    parserN = "parse2"
    For Each cell In range
        cell.Value = preParse(cell.Value, parserN)
    Next cell

    parserN = "parse1"
    For Each cell In range
        cell.Value = preParse(cell.Value, parserN)
    Next cell
End Sub

Function preParse(str As String, genericFunction) as String
    ' Many Lines of code
    ' Verify if it needs to be parsed
    preParse = Run(genericFunction, str) 
    ' More code
End Function