BreakRoleInheritance Error You cannot call a method on a null-valued expression

Question

I have the following piece of code to break role inheritance in specific folder and apply another role

$folder= $web.GetFolder($folderURL)
$folder.Item.BreakRoleInheritance("true")

Success it works fine when I set cleaned url
$folderURL=http://thalabapp01:10574/sites/SiteCollection1/Test3/Test4

Failure It failed in both:

1. I copy full url from browser for the same folder Test4 and set it to $folderURL $folderURL=http://thalabapp01:10574/sites/SiteCollection1/_layouts/15/start.aspx#/DocummentLibrary1/Forms/AllItems.aspx?RootFolder=%2Fsites%2FSiteCollection1%2FDocummentLibrary1%2FTest3%2FTest4&FolderCTID=0x012000CB838094FA7E5547AE67B658B37A595B&View=%7B80AA6D44%2DD5AD%2D496B%2D87C7%2D660CEB513A92%7D

2. Used folder in shared documents http://thalabapp01:10574/sites/SiteCollection1/Documents/Test2

The error is : You cannot call a method on a null-valued expression. At D:\GrantPermissions\GrantPermission.ps1:9 char:4 + $folder.Item.BreakRoleInheritance("true") + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : InvalidOperation: (:) [], RuntimeException + FullyQualifiedErrorId : InvokeMethodOnNull

Please advice !

Answer 1

The SPWeb.GetFolder method accepts server-relative URL for the folder. This is the reason why your 'clean' url works and your 'browser' url doesn't.

The error you are getting for 'shared documents' folder most likely indicates that this folder doesn't exist. Try pasting the url in browser to verify it.

It is always smart to check if the folder you are trying to get exist before you try to access it. So your code should be something like this:

$folder= $web.GetFolder($folderURL)
if($folder.Exist -eq $true) {
    $folder.Item.BreakRoleInheritance($true)
}

Also in PS it isn't "true". It is $true.

UPDATE:

Only way to use 'browser' url is to extract folder server-relative URL from it. The code is not generic so I cannot guarantee that it will work for all url formats:

$browserUrl = "http://thalabapp01:10574/sites/SiteCollection1/_layouts/15/start.aspx#/DocummentLibrary1/Forms/AllItems.aspx?RootFolder=%2Fsites%2FSiteCollection1%2FDocummentLibrary1%2FTest3%2FTest4"
[URI]$url = $browserUrl
#It is a bit difficult to extract the RootFolder from this Url
$start = $browserUrl.IndexOf("RootFolder=") + 11
$end = $browserUrl.Substring($start, $browserUrl.Length - $start).IndexOf("&")
if($end -eq -1) {$end = $browserUrl.Length - $start}
$folderURL = $url.Scheme + "://" + $url.Authority + [System.Web.HttpUtility]::UrlDecode($browserUrl.Substring($start, $end))
# in this case $folderUrl = http://thalabapp01:10574/sites/SiteCollection1/DocummentLibrary1/Test3/Test4