about_InlineScript

Article
09/19/2022

Short description

Describes the InlineScript activity, that runs PowerShell commands in a workflow.

Long description

The InlineScript activity runs commands in a shared PowerShell session's workflow. InlineScript is only valid in workflows.

Syntax

InlineScript {<script block>} <ActivityCommonParameters>

Detailed description

The InlineScript activity runs commands in a shared PowerShell session. You can include it in a workflow to run commands that share data and commands that aren't otherwise valid in a workflow.

The InlineScript script block can include all valid PowerShell commands and expressions. Because the commands and expressions in an InlineScript script block run in the same session, they share all state and data, including imported modules and the values of variables.

You can place an InlineScript activity anywhere in a workflow or nested workflow, including inside a loop or control statement or a Parallel or Sequence script block.

The InlineScript activity has the activity common parameters, including PSPersist. However, the commands and expressions in an InlineScript script block don't have the workflow features such as checkpointing, or persistence, and workflow or activity common parameters. For more information, see about_ActivityCommonParameters.

InlineScript Variables

By default, the variables that are defined in a workflow aren't visible to the commands in the InlineScript script block. To make workflow variables visible to the InlineScript, use the $Using scope modifier. The $Using scope modifier is required only once for each variable in the InlineScript.

For more information about the $Using scope modifier, see about_Remote_Variables.

The following example shows that the $Using scope modifier makes the value of the $a top-level workflow variable available to the commands in the InlineScript script block.

workflow Test-Workflow {
  $a = 3

  ## Without $Using, the $a workflow variable isn't visible
  ## in inline script.
  InlineScript {"Inline A0 = $a"}

  ## $Using imports the variable and its current value.
  InlineScript {"Inline A1 = $Using:a"}
}

Test-Workflow

Inline A0 =
Inline A1 = 3

Returning variables in InlineScript

InlineScript commands can change the value of the variable that was imported from workflow scope, but the changes aren't visible in workflow scope. To make them visible, return the changed value to the workflow scope, as shown in the following example.

workflow Test-Workflow {
  $a = 3

  ##  Changes to the InlineScript variable value don't
  ##  change the workflow variable.
  InlineScript {
    $a = $Using:a+1;
    "Inline A = $a"
  }
  "Workflow A = $a"

  ##  To change the variable in workflow scope, return the
  ##  new value.
  $a = InlineScript {$b = $Using:a+1; $b}
  "Workflow New A = $a"
}

Test-Workflow

Inline A = 4
Workflow A = 3
Workflow New A = 4

Note

A statement with the $Using scope modifier should appear before any use of the variable in the InlineScript script block.

Running in-process

To improve reliability, the commands in the InlineScript script block run in their own process, separate from the process in which the workflow runs, and then return their output to the workflow process.

To direct PowerShell to run the InlineScript activity in the workflow process, remove the InlineScript value from the OutOfProcessActivity property of the session configuration, such as by using the New-PSWorkflowExecutionOption cmdlet.

Example

The InlineScript in the following workflow includes commands that are valid in PowerShell but aren't valid in workflows. For example, the New-Object cmdlet with the ComObject parameter.

workflow Test-Workflow
{
  $ie = InlineScript {
    $ie = New-Object -ComObject InternetExplorer.Application -Property @{navigate2="www.microsoft.com"}

    $ie.Visible = $true
  }

  $ie
}

Test-Workflow

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