Attach workflow to all webs

So I've made my own custom approval state machine workflow and now I need to attach it to everyone of my subsites. how do I accomplish this? Well any time you're face with a cumbersome amount of pointing and clicking you have two alternatives:

• Feature event receiver 
• PowerShell

Now as I learned the hard way you're event receiver has a 2 minute time out, so in my case where I'm attaching a workflow to three libraries on every subsite and creating a custom task list it really didn't pan out. Instead I ended up moving my logic out of my visual studio project and into a powershell script. I'm going to break this script down into Five sections.

Section One (Start up)

#get the site url to deploy workflow to

param($siteUrl=$(read-host "Please provide web app url of the list to be delete (EG:'http://Wingtip'):"))

#ensure that user provided site url parameter

if($siteUrl -eq $null -or $siteUrl -eq '')

{

    throw "You must specify your server name. Value provided was null/empty."

}

#function to load SharePoint Powershell snap in

function LoadSharePointPowerShellEnviroment

{

 #clear the screen of pevious output

 Clear-Host

 write-host "Setting up Powershell enviroment for Sharepoint" -foregroundcolor Blue

 Add-PSSnapin "Microsoft.Sharepoint.PowerShell" -ErrorAction SilentlyContinue

 Write-host "Sharepoint PowerShell Snapin loaded." -foregroundcolor Green

}

#call sharepoint plugin function

LoadSharePointPowerShellEnviroment

Section Two(Declare Constants)

#get site using parameter

$site = Get-SPSite($siteUrl)

#get the rootweb of the site

$rootWeb = $site.RootWeb

#ensure that approval workflow has unique name

$workFlowName = "Approval_" +  [System.DateTime]::Now.ToString()

#specify the approval task list name

$TASKLISTNAME = "Approval Tasks"

#specify the task list description

$listDescription = "Task list for ccw custom approval tasks"

#reference approval task list definition, deployed through VS project

$TaskListTemplate= $rootWeb.ListTemplates["Page Approval Task List Definition"]

#specify OOTB workflow history list, every site has one

$HISTORYLISTNAME = "Workflow History"

#approval workflow ID, specified in elements file of workflow

$APPROVALWORKFLOWID = [GUID]"64f076cb-a5f8-4ee7-9ef4-54820d291886"

#reference workflow using workflow ID

$wfTemplate = $rootWeb.WorkflowTemplates[$APPROVALWORKFLOWID]

Section Three(Create list function)

#Create List Instance function

function createListInstance($web, $listName, $listDescription)

{

      #make sure list doesn't already exist

      if($web.Lists.TryGetList($listName) -eq $null)

      {

            #create list with no spaces

            $listGuid = $web.Lists.Add($listname.Replace(" ",""), $listDescription, $TaskListTemplate)

           

            #grab the list, change the name to the original parameter passed to the function

            $list = $web.Lists[$ListGuid]

            $list.title = $listName

            $list.Update()

      }

      else

      {

            Write-Host $listName + "was not created on web" + $web.Url -ForegroundColor Red;

      }

      $web.Dispose()

}

Section Four(Attach workflow function)

#attach workflow to web

function addApprovalWorkflow($web, $listname)

{

      #get the library you want to attach the workflow to

    $library = $web.Lists.TryGetList($listname)

   

      #ensure library exists

    if($library -ne $null)

    {

            #reference tasklist, and histrory list on web

        $taskList = $web.Lists[$TASKLISTNAME]

        $historyList = $web.Lists[$HISTORYLISTNAME]

       

            #create a workflow association refer to

        $workflowAssociation = [Microsoft.SharePoint.Workflow.SPWorkflowAssociation]::CreateListAssociation($wfTemplate, $workflowName, $taskList, $historyList);

       

            #set the properties of the workflow assocation

        $workflowAssociation.Name = $workFlowName

        $workflowAssociation.AllowManual = $true

        $workflowAssociation.AutoStartChange = $true

        $workflowAssociation.AutoStartCreate = $true

       

            #attach the workflow association to the Library

        $temp = $library.WorkflowAssociations.Add($workflowAssociation);

        $workflowAssociation.Enabled = $true;

            $web.Dispose()

    }

}

Section Five(Main)

#itterate through all subsites

$webs = $site.AllWebs

foreach ($web in $webs)

{

      #ignore the search site

      if($web.Title -eq "Search")

      {

            continue

      }

     

      Write-Host $web.Url

      #create the task list

      createListInstance $web $TASKLISTNAME $listDescription

     

      #Attach the approval wf to libraries

      addApprovalWorkflow  $web "Pages"

      addApprovalWorkflow  $web "Images"

    addApprovalWorkflow  $web "Documents"

    $web.Dispose()

}

$rootWeb.Dispose()

$site.Dispose()

write-host "Complete" -ForegroundColor Blue