CancellationTokenEvent

CancellationToken tools for PowerShell

Register-CancellationTokenEvent

Use CancellationToken with PowerShell events

Example code

$cancellationTokenSource = New-Object -Type System.Threading.CancellationTokenSource

$cancellationEvent = Register-CancellationTokenEvent -CancellationToken $cancellationTokenSource.Token

Register-ObjectEvent -InputObject $cancellationEvent -EventName 'Cancelled' -SourceIdentifier 'CancellationToken'

This allows the usage of the standard PowerShell event sourced by the cancellation token.

The dotnet object used has a Cancelled event that can be consumed by Register-ObjectEvent.

public class CancellationTokenEventRegistration : IDisposable
{
    public event Action Cancelled;
    public void Dispose() => CancellationTokenRegistration.Dispose();
    private readonly IDisposable CancellationTokenRegistration;
    public CancellationTokenEventRegistration(System.Threading.CancellationToken ct)
    {
        CancellationTokenRegistration = ct.Register(() => Cancelled());
    }
}

When the cancellation is triggered it will invoke the Cancelled action event. When the registration is no longer needed then call Dispose to unregister. See UnitTests/CancellationTokenTests.ps1 for full example.

Invoke-CommandWithCancellationToken

Use a CancellationToken to stop a ScriptBlock

Example code

$cancellationTokenSource = New-Object -Type System.Threading.CancellationTokenSource
$cancellationTokenSource.CancelAfter(5000)
$cancellationToken = $cancellationTokenSource.Token

Invoke-CommandWithCancellationToken -ScriptBlock {
    Wait-Event
} -CancellationToken $cancellationToken -NoNewScope

This will stop the Wait-Event after 5 seconds. Internally this works by running the ScriptBlock with Invoke-Command and using the CancellationToken to call Stop.

Build

To build use

dotnet publish CancellationTokenEvent.csproj --configuration Release

This will populate the module directory

$ ls bin/Release/netstandard2.0/rhubarb-geek-nz.CancellationTokenEvent
README.md
RhubarbGeekNz.CancellationTokenEvent.Registration.dll
RhubarbGeekNz.CancellationTokenEvent.PSCmdlet.dll
rhubarb-geek-nz.CancellationTokenEvent.psd1