SharePoint Start Workflow on All Items of a List via PowerShell

To start a List Workflow in SharePoint on All Items of a list is a pain through GUI but it's a piece of cake in PowerShell. Note that the Workflow will not start instantly (as opposed to triggering through the UI) but in maximum 5 minutes because it's started through the SharePoint Timer Service.

#updated on 10/17/2013

# URL of the Site
$web = Get-SPWeb -Identity "https://sharepointsrv/site1"

$manager = $web.Site.WorkFlowManager

# Name of the list
$list = $web.Lists["Shared Documents"]

# Name of the Workflow
$assoc = $list.WorkflowAssociations.GetAssociationByName("On Item Created","en-US")

$data = $assoc.AssociationData
$items = $list.Items
foreach($item in $items)
 {
 $wf = $manager.StartWorkFlow($item,$assoc,$data,$true)
 }
 
$manager.Dispose()
$web.Dispose()
#

References

• http://social.technet.microsoft.com/Forums/sharepoint/en-US/dffdceab-f2fe-4886-8e2a-ea26cf08c78a/how-to-start-a-speific-workflow-programatically-in-sharepoint-2010-via-powershell