Powershell error while iterating through sites quicklaunch and deleting a specific node

Question

Hi I've put this question up here : https://stackoverflow.com/questions/13130785/delete-navigation-node-with-powershell-from-sharepoint-quicklaunch-in-all-sites but no answer yet so posting here too.

I've put together a powershell script to delete a specific quicklaunch node in sharepoint 2010. It works on a dummy site collection, but fails on another (migrated sites from sp2007).

Here is the script:

Add-PSSnapin Microsoft.SharePoint.PowerShell -erroraction SilentlyContinue 
$site = Get-SPSite http://site.com/SITES/OFFICES/
$site | get-spweb -limit all | foreach-object{ 
$webURL = $_.url 
$web = Get-SPWeb $webURL 

$navigationNodes = $web.Navigation.QuickLaunch 
ForEach ($Node in $NavigationNodes) 
{ 
 if($node.Title -eq "People and Group") 
    { 
    write-host $web.URL "...node exists here"   
    {continue}  
    $node.Delete()
    $web.update() 
    write-host $web.URL "...node removed"    
    } 
} 

 $web.Dispose() 
 }

The error I get when running as SP_Admin is :

Get-SPWeb : The pipeline has been stopped. At line:3 char:18 + $site | Get-SPWeb <<<< -limit all | foreach-object { + CategoryInfo : InvalidData: (Microsoft.Share....SPCmdletGetWeb:SPCmdletGetWeb) [Get-SPWeb], PipelineStoppedException + FullyQualifiedErrorId : Microsoft.SharePoint.PowerShell.SPCmdletGetWeb

ForEach-Object : Cannot complete this action.

Please try again. At line:3 char:46 + $site | Get-SPWeb -limit all | foreach-object <<<< { + CategoryInfo : NotSpecified: (:) [ForEach-Object], SPException + FullyQualifiedErrorId : Microsoft.SharePoint.SPException,Microsoft.PowerShell.Commands.ForEachObjectCommand

I am new to powershell so trying to debug the issue - do I need to build an array of the nodes before deleting them?

Any guidance would be great. Thanks Rich

Answer 1

You need to delete the items in reverse order. this is because you cannot modify the collection inside the foreach loop.

Do the below:

SPNavigationNodeCollection nodes = myPublishingWeb.Navigation.CurrentNavigationNodes;

                    //deleting unwanted
                    int nodesCount = nodes.Count;
                    for (int nodeIndex = nodesCount; nodeIndex > 0; nodeIndex--)
                    {
                        SPNavigationNode spNodes = nodes[nodeIndex - 1];

                        foreach (string unWantedNode in unWantedNodes)
                        {
                            if (spNodes.Title.ToString() == unWantedNode)
                            {
                                spNodes.Delete();
                            }
                        }
                    }

myPublishingWeb.Update();
                    webSite.Update();

UPDATE: unWantedNode is just an array of strings. You loop through existing SP nodes & if there is a match with any of your required nodes, you proceed with delete.

I do not have exact code, but I can give algorithm as below:

string[] unWantedNodes = {"Complaince"};
SPNavigationNodeCollection nodes = myPublishingWeb.Navigation.CurrentNavigationNodes;

                    //deleting unwanted
                    int nodesCount = nodes.Count;
                    for (int nodeIndex = nodesCount; nodeIndex > 0; nodeIndex--)
                    {
                        SPNavigationNode spNodes = nodes[nodeIndex - 1];

                        foreach (string unWantedNode in unWantedNodes)
                        {
                            if (spNodes.Title.ToString() == unWantedNode)
                            {
                               //HERE again get the list of children using spNodes.Childre... & then do the same deleting logic for child nodes
                               spNodes.Update();
                                spNodes.Delete();

                            }
                        }
                    }

myPublishingWeb.Update();
                    webSite.Update();