Combining parameter sets - powershell

Question

This is somewhat related to a question I asked earlier; Group parameter (set?) requiring one of the parameters
I have a set of 5 parameters; Years, Months, Days, Path, Input. I'm looking to combine parameter sets so that I can have the following combinations;
Years & (Path or Input)
Months & (Path or Input)
Days & (Path or Input)
Path is a typed path and Input is a pointer to a file, either way, one of them is required.
I've tried
[Parameter(Mandatory = $true, ParameterSetName = 'Path')]
[Parameter(Mandatory = $true, ParameterSetName = 'Input')
[int]$Years = '7'
But Path & Input are required if using Years
Param (
[parameter(Position = 0, ValueFromPipeline = $True, ValueFromPipelineByPropertyName = $True)]
[string[]]$Filter = '*.*',
[Parameter(Mandatory = $True, ParameterSetName = 'ByYears')]
[int]$Years = '7',
[Parameter(Mandatory = $True, ParameterSetName = 'ByMonths')]
[int]$Months,
[Parameter(Mandatory = $True, ParameterSetName = 'ByDay')]
[int]$Days,
[Parameter(Mandatory = $true, ParameterSetName = 'Path')]
[string[]]$Path,
[Parameter(Mandatory = $true, ParameterSetName = 'Input')]
[string]$Input,
[switch]$Recurse,
[Parameter(Mandatory = $true)]
[string]$ReportPath = $PWD
)
In the end I'm looking to have the possibility of only one of the combinations below;
-Years 2 -Path C:\Temp
-Years 2 -Input C:\Temp\file.txt
-Months 2 -Path C:\Temp
-Months 2 -Input C:\Temp\file.txt
-Days 2 -Path C:\Temp
-Days 2 -Input C:\Temp\file.txt

Answer 1

There's no way of directly expressing ParameterA and (ParameterB or ParameterC) in ParameterSets but you can create two ParameterSets: ParameterA and ParameterB and ParameterA and ParameterC which does the same thing.
If you extend that to your scenario, you'll need 6 ParameterSets:
YearsAndPath
YearsAndInput
MonthsAndPath
MonthsAndInput
DaysAndPath
DaysAndInput
And then you just tag each parameter with the ParameterSets it needs to be used in, and your param block becomes something like:
function Invoke-Params
{
param(
[parameter(Position = 0, ValueFromPipeline = $True, ValueFromPipelineByPropertyName = $True)]
[string[]]$Filter = '*.*',
[Parameter(Mandatory = $True, ParameterSetName = 'YearsAndPath')]
[Parameter(Mandatory = $True, ParameterSetName = 'YearsAndInput')]
[int]$Years = '7',
[Parameter(Mandatory = $True, ParameterSetName = 'MonthsAndPath')]
[Parameter(Mandatory = $True, ParameterSetName = 'MonthsAndInput')]
[int]$Months,
[Parameter(Mandatory = $True, ParameterSetName = 'DaysAndPath')]
[Parameter(Mandatory = $True, ParameterSetName = 'DaysAndInput')]
[int]$Days,
[Parameter(Mandatory = $true, ParameterSetName = 'YearsAndPath')]
[Parameter(Mandatory = $true, ParameterSetName = 'MonthsAndPath')]
[Parameter(Mandatory = $true, ParameterSetName = 'DaysAndPath')]
[string[]]$Path,
[Parameter(Mandatory = $true, ParameterSetName = 'YearsAndInput')]
[Parameter(Mandatory = $true, ParameterSetName = 'MonthsAndInput')]
[Parameter(Mandatory = $true, ParameterSetName = 'DaysAndInput')]
[string]$Input,
[switch]$Recurse,
[Parameter(Mandatory = $true)]
[string]$ReportPath = $PWD
)
}
The following then work fine:
PS> Invoke-Params -Years 5 -Path "xxx"
PS> Invoke-Params -Years 5 -Input "xxx"
and these throw an exception:
PS> Invoke-Params -Years 5
Invoke-Params : Parameter set cannot be resolved using the specified named parameters.
At line:1 char:1
+ Invoke-Params -Years 5
+ ~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidArgument: (:) [Invoke-Params], ParameterBindingException
+ FullyQualifiedErrorId : AmbiguousParameterSet,Invoke-Params
PS> Invoke-Params -Years 5 -Path "aaa" -Input "bbb"
Invoke-Params : Parameter set cannot be resolved using the specified named parameters.
At line:1 char:1
+ Invoke-Params -Years 5 -Path "aaa" -Input "bbb"
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidArgument: (:) [Invoke-Params], ParameterBindingException
+ FullyQualifiedErrorId : AmbiguousParameterSet,Invoke-Params

Answer 2

The answer by mclayton is correct in that you would have to use 6 parameter set names.
There are three 'time' parameters that should rule each other out and must be used together with either one of two 'path' parameters.
However, you should not use $input as parameter, since this is an Automatic variable as Mathias R. Jessen already commented, and because you are setting up the $Years parameter with a default value, Mandatory should be $false on that one.
Because using combinations of parameter sets is always a puzzle, I would put the parameters in a more logical order (at least to me..) by first defining the two 'path' parameters and setting the DefaultParameterSetName to be the first of those.
By also adding Position = 0 on that first parameter, you can call the function with just the path without having to name it.
Just play around with the function below to see what combinations are possible and what the function will use:
function Show-Parameters {
[CmdletBinding(DefaultParameterSetName = 'ByFolderYears')]
param (
[Parameter(Mandatory = $true, Position = 0, ValueFromPipeline = $true, ParameterSetName = 'ByFolderYears')]
[Parameter(Mandatory = $true, Position = 0, ValueFromPipeline = $true, ParameterSetName = 'ByFolderMonths')]
[Parameter(Mandatory = $true, Position = 0, ValueFromPipeline = $true, ParameterSetName = 'ByFolderDays')]
[Alias('Path')]
[string[]]$FolderPath,
[Parameter(Mandatory = $true, ParameterSetName = 'ByFileYears')]
[Parameter(Mandatory = $true, ParameterSetName = 'ByFileMonths')]
[Parameter(Mandatory = $true, ParameterSetName = 'ByFileDays')]
[Alias('File')]
[string]$FilePath,
[Parameter(Mandatory = $false, ParameterSetName = 'ByFolderYears')]
[Parameter(Mandatory = $false, ParameterSetName = 'ByFileYears')]
[int]$Years = 7,
[Parameter(Mandatory = $true, ParameterSetName = 'ByFolderMonths')]
[Parameter(Mandatory = $true, ParameterSetName = 'ByFileMonths')]
[int]$Months,
[Parameter(Mandatory = $true, ParameterSetName = 'ByFolderDays')]
[Parameter(Mandatory = $true, ParameterSetName = 'ByFileDays')]
[int]$Days,
[string[]]$Filter = '*.*',
[string]$ReportPath = $PWD,
[switch]$Recurse
)
# just to show what parameter the function will use
$paramsUsed = [ordered]#{}
$paramSet = $PSCmdlet.ParameterSetName
if ($paramSet.StartsWith('ByFolder')) { $paramsUsed['FolderPath'] = $FolderPath -join '; ' }
else {$paramsUsed['FilePath'] = $FilePath}
if ($paramSet.EndsWith('Years')) { $paramsUsed['Years'] = $Years }
elseif ($paramSet.EndsWith('Months')) { $paramsUsed['Months'] = $Months }
else { $paramsUsed['Days'] = $Days }
if ($Filter) { $paramsUsed['Filter'] = $Filter -join '; ' }
if ($ReportPath) { $paramsUsed['ReportPath'] = $ReportPath }
if ($Recurse) { $paramsUsed['Recurse'] = $Recurse }
Write-Host "Using ParameterSet '$paramSet'" -ForegroundColor Cyan
$paramsUsed
}
For instance
Show-Parameters 'D:\some\path', 'Z:\some\folder'
outputs
Using ParameterSet 'ByFolderYears'
Name Value
---- -----
FolderPath D:\some\path; Z:\some\folder
Years 7
Filter *.*
ReportPath C:\Users\YourName
etc.