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function Get-NumberRange
{
[cmdletbinding()]
Param()
DynamicParam {
$Dictionary = New-Object System.Management.Automation.RuntimeDefinedParameterDictionary
$NewDynParam = @{
Name = "Firstnumber"
Alias = "int"
Mandatory = $true
DPDictionary = $Dictionary
}
$NumberRange = @(1,2,3,4,5)
$null = $NewDynParam.Add("ValidateSet",$NumberRange)
if(-not (Get-Variable -Scope Global | Where-Object Name -eq "HiddenNumberVariable"))
{
New-Variable -Name HiddenNumberVariable -Scope Global
}
# Create the Firstnumber parameter
New-DynamicParam @NewDynParam -Type int -ValidateScript {$null = Set-Variable -Name HiddenNumberVariable -Value $_ -Scope Global;$true}
$SecondNumberRange = @(1,2,3,4,5)
if(Get-Variable -Scope Global | Where-Object Name -eq "HiddenNumberVariable")
{
$SecondNumberRange = $SecondNumberRange | Where-Object {$_ -gt (Get-Variable -Name HiddenNumberVariable -Scope Global).Value}
}
# Create the SecondNumber parameter
New-DynamicParam -Name SecondNumber -Type int -ValidateSet $SecondNumberRange -DPDictionary $Dictionary
#out-file -FilePath C:\temp\dynpara.txt -Encoding utf8 -InputObject (Get-Variable -Scope Global | where name -eq "HiddenNumberVariable" | out-string)
# Return the parameters
$Dictionary
Get-Variable -Name HiddenNumberVariable -Scope Global -ErrorAction SilentlyContinue | Remove-Variable -Scope Global
}
BEGIN{
# Remove variable from the global scope, we don't need it anymore
Get-Variable -Name HiddenNumberVariable -Scope Global -ErrorAction SilentlyContinue | Remove-Variable -Scope Global
}
PROCESS{
[pscustomobject]$PSBoundParameters
}
END{
}
}
function New-DynamicParam
{
<#
.SYNOPSIS
Helper function to simplify creating dynamic parameters
.DESCRIPTION
Helper function to simplify creating dynamic parameters
Example use cases:
Include parameters only if your environment dictates it
Include parameters depending on the value of a user-specified parameter
Provide tab completion and intellisense for parameters, depending on the environment
Please keep in mind that all dynamic parameters you create will not have corresponding variables created.
One of the examples illustrates a generic method for populating appropriate variables from dynamic parameters
Alternatively, manually reference $PSBoundParameters for the dynamic parameter value
.NOTES
Credit to http://jrich523.wordpress.com/2013/05/30/powershell-simple-way-to-add-dynamic-parameters-to-advanced-function/
Added logic to make option set optional
Added logic to add RuntimeDefinedParameter to existing DPDictionary
Added a little comment based help
Credit to https://github.com/RamblingCookieMonster/PowerShell/blob/master/New-DynamicParam.ps1
Credit to BM for alias and type parameters and their handling
.PARAMETER Name
Name of the dynamic parameter
.PARAMETER Type
Type for the dynamic parameter. Default is string
.PARAMETER Alias
If specified, one or more aliases to assign to the dynamic parameter
.PARAMETER ValidateSet
If specified, set the ValidateSet attribute of this dynamic parameter
.PARAMETER Mandatory
If specified, set the Mandatory attribute for this dynamic parameter
.PARAMETER ParameterSetName
If specified, set the ParameterSet attribute for this dynamic parameter
.PARAMETER Position
If specified, set the Position attribute for this dynamic parameter
.PARAMETER ValueFromPipelineByPropertyName
If specified, set the ValueFromPipelineByPropertyName attribute for this dynamic parameter
.PARAMETER HelpMessage
If specified, set the HelpMessage for this dynamic parameter
.PARAMETER DPDictionary
If specified, add resulting RuntimeDefinedParameter to an existing RuntimeDefinedParameterDictionary (appropriate for multiple dynamic parameters)
If not specified, create and return a RuntimeDefinedParameterDictionary (appropriate for a single dynamic parameter)
See final example for illustration
.EXAMPLE
function Show-Free
{
[CmdletBinding()]
Param()
DynamicParam {
$options = @( gwmi win32_volume | %{$_.driveletter} | sort )
New-DynamicParam -Name Drive -ValidateSet $options -Position 0 -Mandatory
}
begin{
#have to manually populate
$drive = $PSBoundParameters.drive
}
process{
$vol = gwmi win32_volume -Filter "driveletter='$drive'"
"{0:N2}% free on {1}" -f ($vol.Capacity / $vol.FreeSpace),$drive
}
} #Show-Free
Show-Free -Drive <tab>
# This example illustrates the use of New-DynamicParam to create a single dynamic parameter
# The Drive parameter ValidateSet populates with all available volumes on the computer for handy tab completion / intellisense
.EXAMPLE
# I found many cases where I needed to add more than one dynamic parameter
# The DPDictionary parameter lets you specify an existing dictionary
# The block of code in the Begin block loops through bound parameters and defines variables if they don't exist
Function Test-DynPar{
[cmdletbinding()]
param(
[string[]]$x = $Null
)
DynamicParam
{
#Create the RuntimeDefinedParameterDictionary
$Dictionary = New-Object System.Management.Automation.RuntimeDefinedParameterDictionary
New-DynamicParam -Name AlwaysParam -ValidateSet @( gwmi win32_volume | %{$_.driveletter} | sort ) -DPDictionary $Dictionary
#Add dynamic parameters to $dictionary
if($x -eq 1)
{
New-DynamicParam -Name X1Param1 -ValidateSet 1,2 -mandatory -DPDictionary $Dictionary
New-DynamicParam -Name X1Param2 -DPDictionary $Dictionary
New-DynamicParam -Name X3Param3 -DPDictionary $Dictionary -Type DateTime
}
else
{
New-DynamicParam -Name OtherParam1 -Mandatory -DPDictionary $Dictionary
New-DynamicParam -Name OtherParam2 -DPDictionary $Dictionary
New-DynamicParam -Name OtherParam3 -DPDictionary $Dictionary -Type DateTime
}
#return RuntimeDefinedParameterDictionary
$Dictionary
}
Begin
{
#This standard block of code loops through bound parameters...
#If no corresponding variable exists, one is created
#Get common parameters, pick out bound parameters not in that set
Function _temp { [cmdletbinding()] param() }
$BoundKeys = $PSBoundParameters.keys | Where-Object { (get-command _temp | select -ExpandProperty parameters).Keys -notcontains $_}
foreach($param in $BoundKeys)
{
if (-not ( Get-Variable -name $param -scope 0 -ErrorAction SilentlyContinue ) )
{
New-Variable -Name $Param -Value $PSBoundParameters.$param
Write-Verbose "Adding variable for dynamic parameter '$param' with value '$($PSBoundParameters.$param)'"
}
}
#Appropriate variables should now be defined and accessible
Get-Variable -scope 0
}
}
# This example illustrates the creation of many dynamic parameters using New-DynamicParam
# You must create a RuntimeDefinedParameterDictionary object ($dictionary here)
# To each New-DynamicParam call, add the -DPDictionary parameter pointing to this RuntimeDefinedParameterDictionary
# At the end of the DynamicParam block, return the RuntimeDefinedParameterDictionary
# Initialize all bound parameters using the provided block or similar code
.FUNCTIONALITY
PowerShell Language
#>
param(
[string]$Name
,
[System.Type]$Type = [string]
,
[string]$TypeAsString
,
[string[]]$Alias = @()
,
[string[]]$ValidateSet
,
[scriptblock]$validateScript
,
[switch]$Mandatory
,
[string]$ParameterSetName = "__AllParameterSets"
,
[int]$Position
,
[switch]$ValueFromPipelineByPropertyName
,
[switch]$ValueFromPipeline
,
[string]$HelpMessage
,
[validatescript({
if(-not ( $_ -is [System.Management.Automation.RuntimeDefinedParameterDictionary] -or -not $_) )
{
Throw "DPDictionary must be a System.Management.Automation.RuntimeDefinedParameterDictionary object, or not exist"
}
$True
})]
$DPDictionary = $false
)
Add-Type @"
public class DynParamQuotedString {
public DynParamQuotedString(string quotedString) : this(quotedString, "'") {}
public DynParamQuotedString(string quotedString, string quoteCharacter) {
OriginalString = quotedString;
_quoteCharacter = quoteCharacter;
}
public string OriginalString { get; set; }
string _quoteCharacter;
public override string ToString() {
if (OriginalString.Contains(" ")) {
return string.Format("{1}{0}{1}", OriginalString, _quoteCharacter);
}
else {
return OriginalString;
}
}
}
"@
if($PSBoundParameters.ContainsKey("TypeAsString"))
{
$type = [System.Type]$TypeAsString
}
#Create attribute object, add attributes, add to collection
$ParamAttr = New-Object System.Management.Automation.ParameterAttribute
$ParamAttr.ParameterSetName = $ParameterSetName
if($mandatory)
{
$ParamAttr.Mandatory = $True
}
if($Position -ne $null)
{
$ParamAttr.Position=$Position
}
if($ValueFromPipelineByPropertyName)
{
$ParamAttr.ValueFromPipelineByPropertyName = $True
}
if($ValueFromPipeline)
{
$ParamAttr.ValueFromPipeline = $True
}
if($HelpMessage)
{
$ParamAttr.HelpMessage = $HelpMessage
}
$AttributeCollection = New-Object 'Collections.ObjectModel.Collection[System.Attribute]'
$AttributeCollection.Add($ParamAttr)
#param validation set if specified
if($ValidateSet)
{
$ParamOptions = New-Object System.Management.Automation.ValidateSetAttribute -ArgumentList $ValidateSet
$AttributeCollection.Add($ParamOptions)
}
if($validateScript)
{
$paramScript = New-Object -TypeName System.Management.Automation.ValidateScriptAttribute -ArgumentList $validateScript
$AttributeCollection.Add($paramScript)
}
#Aliases if specified
if($Alias.count -gt 0) {
$ParamAlias = New-Object System.Management.Automation.AliasAttribute -ArgumentList $Alias
$AttributeCollection.Add($ParamAlias)
}
#Create the dynamic parameter
$Parameter = New-Object -TypeName System.Management.Automation.RuntimeDefinedParameter -ArgumentList @($Name, $Type, $AttributeCollection)
#Add the dynamic parameter to an existing dynamic parameter dictionary, or create the dictionary and add it
if($DPDictionary)
{
$DPDictionary.Add($Name, $Parameter)
}
else
{
$Dictionary = New-Object System.Management.Automation.RuntimeDefinedParameterDictionary
$Dictionary.Add($Name, $Parameter)
$Dictionary
}
}
@jkdba

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@jkdba jkdba commented Sep 28, 2016

This is awesome, thanks.

@torgro

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Owner Author

@torgro torgro commented Sep 29, 2016

Lovely, thx 👍

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