Parameters

Parameters for PowerShell Universal jobs.

Parameters

Jobs support automatically generating forms with parameters based on your script's param block. The type of control will change based on the type you define in the block. Parameters that are mandatory will also be required by the UI.

Basic Parameters

Parameters can be simply defined without any type of parameter attribute and they will show up as text boxes in the UI.

param($Test)

$Test

Parameters Types

Universal supports various types of parameters. You can use String, String[], Int, DateTime, Boolean, Switch and Enum types.

String

You can define string parameters by specifying the [String] type of by not specifying a type at all. Strings will generate a textbox.

param(
    [String]$Textbox,
    $Textbox2
)

String Arrays

You can specify string arrays by using the [String[]] type specifier. String arrays will generate a multi-tag select box.

param([String[]]$Array)

Date and Time

You can use the [DateTime] type specifier to create a date and time selector.

param([DateTime]$DateTime)

Boolean

You can use a [Bool] type selector to create a switch.

param([Bool]$Switch)

Integer

You can define a number selector by using the [Int] type specifier.

param([Int]$Number)

Switch Parameter

You can define a switch parameter using the [Switch] type specifier to create a switch.

param([Switch]$Switch)

Enumerations

You can use System.Enum values to create select boxes. For example, you could use the System.DayOrWeek to create a day of the week selection box.

param([System.DayOfWeek]$DayOfWeek)

PSCredential

When you specify a PSCredential , the user will be presented with a drop down of credentials available as variables.

param(
    [PSCredential]$Credential
)

File

You can allow users to upload files by using the [File] type.

param(
    [File]$File
)

Files will be available as a PSUFile object in your scripts. This object has a byte[] array that you can use to process the file.

For example, you can get the string content for the file by converting it using the Encoding classes.

[Text.Encoding]::UTF8.GetString($File.Content)

Display Name

You can use the DisplayNameAtrribute to set a display name for the script parameter.

param(
    [ComponentModel.DisplayName("My Script")]
    $MyScript
)

Help Messages

You can define help messages for your parameters by using the HelpMessage property of the Parameter attribute.

param(
    [Parameter(HelpMessage = "Class you want to enroll in")]
    [string]$Class
)

Required Parameters

You can use the Parameter attribute to define required parameters.

param(
    [Parameter(Mandatory)]
    $RequiredParameter
)

$RequiredParameter

Default Value

You can use both static and default values for parameters. The default value is calculated when the job is about to be run.

param(
    $Parameter = "Hello, World",
    [DateTime]$ExecutionTime = Get-Date
)

$Parameter
$ExecutionTime

ValidateSet

The ValidateSet attribute is used to enforce which values can be passed to a parameter. Learn about ValidateSet here. PowerShell Universal will automatically create a drop-down menu with the values provided to the ValidateSet attribute for parameters.

For example, a script could define a param block as follows.

param(
    [ValidateSet("Steve", "Mary")]
    [string]$Name
)

The result is shown below.

ValidateSet Attribute

Passing Parameters from PowerShell

You can pass parameters from PowerShell using the Invoke-PSUScript cmdlet. This cmdlet supports dynamic parameters. If you have a param block on your script, these parameters will automatically be added to Invoke-PSUScript.

For example, I had a script named Script1.ps1 and the contents were are follows.

param($MyParameter)

$MyParameter

I could then invoke that script using this syntax.

Invoke-PSUScript -Name 'Script.ps1' -MyParameter "Hello"

The result would be that Hello was output in the job log and pipeline.

Parameter Sets

PowerShell Universal supports parameter sets. When a parameter set is defined, a drop down is provided that allows for switching between the sets.

param(
    [Parameter(ParameterSetName = 'Set1')]
    $Parameter1,
    [Parameter(ParameterSetName = 'Set2')]
    $Parameter2
)

Parameter Sets