Compound Dynamic Parameters in Powershell - powershell

Question

I am attempting to use two Dynamic Parameters in the same cmdlet. The problem is that I would like the second dynamic parameter to use the first parameter to populate the result set.
For example the syntax for using the command could be something like this -
Get-MSRP -Manufacturer Jeep -Trim Rubicon
'Manufacturer' is a dynamic parameter that looks at a file on the disk to populate values for the user. I would 'Trim' to consume the 'Manufacturer' option that the user chose to create a result set of 'Trim'.
My 'Manufacturer' is working correctly but I believe that the value which the user has chosen isn't available when the code for the DynamicParam I've created for 'Trim', has been ran.
Any help?
function Get-MSRP{
[cmdletbinding()]
param()
DynamicParam{
$Param1 = "Manufacturer",0,{GC c:\temp\manufacturers.txt},$False
$Param2 = "Trim",1,{GC c:\temp\$Manufacturer\Trim.txt},$False
Get-DynamicParameterSet $Param1,$Param2
}
begin{
$Manufacturer = $PSBoundParameters["Manufacturer"]
$Trim = $PSBoundParameters["Trim"]
}
process{
return Invoke-Sqlcmd -Database 'db' -ServerInstance 'server' -Query
"Select MSRP from pricing.MSRP where Manufacturer = '$Manufacturer'
and Trim = '$Trim'"
}
}
function Get-DynamicParameterSet{
param($Params)
$RuntimeParameterDictionary = New-Object
System.Management.Automation.RuntimeDefinedParameterDictionary
if($Params[0].GetType().Name -eq "String" ){
Write-Debug "Single Param to build"
$RuntimeParameterDictionary = BuildSet $Params[0] $Params[1]
$([Scriptblock]$Params[2]) $Params[3] $Params[4] $RuntimeParameterDictionary
}else{
foreach($Param in $Params){
$RuntimeParameterDictionary = BuildSet $Param[0] $Param[1]
$([Scriptblock]$Param[2]) $Param[3] $Param[4]
$RuntimeParameterDictionary
}
}
return $RuntimeParameterDictionary
}
function BuildSet{
param(
$ParameterName,
[int]$Position,
[ScriptBlock]$scriptBlock,
$Mandatory,
$SetNames,
[System.Management.Automation.RuntimeDefinedParameterDictionary]$RuntimeParameterDictionary)
Write-Debug "Setting up $ParameterName"
$AttributeCollection = New-Object System.Collections.ObjectModel.Collection[System.Attribute]
$ParameterAttribute = New-Object System.Management.Automation.ParameterAttribute
$ParameterAttribute.Mandatory = $Mandatory
$ParameterAttribute.Position = $Position
$ParameterAttribute.ParameterSetName = $SetNames
$AttributeCollection.Add($ParameterAttribute)
Write-Debug "Generating result set"
$arrSet = Invoke-Command $scriptBlock
Write-Debug "Generated as $arrSet"
$ValidateSetAttribute = New-Object System.Management.Automation.ValidateSetAttribute($arrSet)
$AttributeCollection.Add($ValidateSetAttribute)
$RuntimeParameter = New-Object System.Management.Automation.RuntimeDefinedParameter($ParameterName, [string], $AttributeCollection)
$RuntimeParameterDictionary.Add($ParameterName, $RuntimeParameter)
return $RuntimeParameterDictionary
}
Minimal & Verifiable
function Get-MSRP{
[cmdletbinding()]
param()
DynamicParam{
$Param1 = "Manufacturer",0,{GC c:\temp\manufacturers.txt},$False
$Param2 = "Trim",1,{gci c:\temp\$Manufacturer},$False
Get-DynamicParameterSet $Param1,$Param2
}
begin{
$Manufacturer = $PSBoundParameters["Manufacturer"]
$Trim = $PSBoundParameters["Trim"]
}
process{
return Invoke-Sqlcmd -Database 'db' -ServerInstance 'server' -Query
"Select MSRP from pricing.MSRP where Manufacturer = '$Manufacturer'
and Trim = '$Trim'"
}
}
function Get-DynamicParameterSet{
param($Params)
$RuntimeParameterDictionary = [System.Management.Automation.RuntimeDefinedParameterDictionary]::new()
foreach($Param in $Params){
$ParameterName = $Param[0]
[int]$Position = $Param[1]
[ScriptBlock]$scriptBlock = $([Scriptblock]$Param[2])
$Mandatory = $Param[3]
$SetNames =$Param[4]
$AttributeCollection = [System.Collections.ObjectModel.Collection[System.Attribute]]::new()
$ParameterAttribute = [System.Management.Automation.ParameterAttribute]::new()
$ParameterAttribute.Mandatory = $Mandatory
$ParameterAttribute.Position = $Position
$ParameterAttribute.ParameterSetName = $SetNames
$AttributeCollection.Add($ParameterAttribute)
$arrSet = Invoke-Command $scriptBlock
$ValidateSetAttribute = New-Object System.Management.Automation.ValidateSetAttribute($arrSet)
$AttributeCollection.Add($ValidateSetAttribute)
$RuntimeParameter = New-Object System.Management.Automation.RuntimeDefinedParameter($ParameterName, [string], $AttributeCollection)
$RuntimeParameterDictionary.Add($ParameterName, $RuntimeParameter)
}
return $RuntimeParameterDictionary
}

Answer 1

After some research, i've found that you cannot have this type of 'Compound dynamic parameter' in powershell where the second dynamic parameter uses a variable output from the users first dynamic parameter. The reason being that the values aren't bound to dynamic parameter until the command is ran.
Another note on Dynamic parameters, the ValueFromPipeline order is not respected when using them!