POWERSHELL - Handling Parameter Sets Gracefully

Question

I have a function:

Function Get-CMAPICollection {
[CmdletBinding()]
param (
    [parameter(ValueFromPipeline = $true, Mandatory = $True, ParameterSetName = "ByName")]
    [string]$collectionName,
    [parameter(ValueFromPipeline = $true, Mandatory = $True, ParameterSetName = "ById")]
    [string]$collectionId
)

If ($collectionName) {
    $URI = "https://$($CMAPI.cmServer)/AdminService/wmi/SMS_Collection?`$filter=Name eq '$collectionName'"
    
}

If ($collectionId) {
    $URI = "https://$($CMAPI.cmServer)/AdminService/wmi/SMS_Collection?`$filter=CollectionId eq '$collectionId'"
}

(Send-CMAPIRequest -method GET -URI $uri).Value

}

Which all works fine.

I'm wondering if there is a better way to dynamically handle the parameters in the function than a bunch of 'If' statements.

My concern is that if I need to add a whole lot of parameter sets, the functions itself is going to have a whole bunch of 'If' statements cluttering up the place.

No matter how far I abstract it out, there is still an 'If' collecionName or 'If' collectionId.

Thanks!

score 1 · Accepted Answer · answered Jan 19 '23 at 00:21

As always, literally minutes after posting I have found the answer. Provided by this answer here:

Which parameter set has been used?

Using the variable:

$PSCmdlet.ParameterSetName

and then a switch statement will reduce the requirement for IF statements.

I suppose this is a duplicate, however I think the question and answer provide some good examples and information.

Fixed function:

Function Get-CMAPICollection {
[CmdletBinding()]
param (
    [parameter(ValueFromPipeline = $true, Mandatory = $True, ParameterSetName = "ByName")]
    [string]$collectionName,
    [parameter(ValueFromPipeline = $true, Mandatory = $True, ParameterSetName = "ById")]
    [string]$collectionId
)

switch ($PSCmdlet.ParameterSetName) {
    byName { $URI = "https://$($CMAPI.cmServer)/AdminService/wmi/SMS_Collection?`$filter=Name eq '$collectionName'" }
    ById { $URI = "https://$($CMAPI.cmServer)/AdminService/wmi/SMS_Collection?`$filter=CollectionId eq '$collectionId'" }
}

(Send-CMAPIRequest -method GET -URI $uri).Value

}

POWERSHELL - Handling Parameter Sets Gracefully

1 Answers1