Change the content type set on files in SharePoint using PowerShell

If you have to make changes to a site content type architecture, the requirement may exist to change a batch of files in a document library from one content type to another. This is usually because you either need to reclassify existing documents to a new content type or move documents to another content type so that unwanted content types can be removed from the list.

The process to change the content type on multiple files using the browser UI is both time consuming and very monotonous. Fortunately, PowerShell can do it for you in a matter of seconds. The script below sets up a function which will look at a document library and modify all files (including those in folders) associated with a specified content type to a different one. Before you can start changing files, run the script below:

function Reset-SPFileContentType ($WebUrl, $ListName, $OldCTName, $NewCTName)
{
    #Get web, list and content type objects
    $web = Get-SPWeb $WebUrl
    $list = $web.Lists[$ListName]
    $oldCT = $list.ContentTypes[$OldCTName]
    $newCT = $list.ContentTypes[$NewCTName]
    $newCTID = $newCT.ID
   
    #Check if the values specified for the content types actually exist on the list
    if (($oldCT -ne $null) -and ($newCT -ne $null))
    {
        #Go through each item in the list
        $list.Items | ForEach-Object {
            #Check if the item content type currently equals the old content type specified
            if ($_.ContentType.Name -eq $oldCT.Name)
            {
                #Check the check out status of the file
                if ($_.File.CheckOutType -eq "None")
                {
                    #Change the content type association for the item
                    $_.File.CheckOut()
                    write-host "Resetting content type for file" $_.Name "from" $oldCT.Name "to" $newCT.Name
                    $_["ContentTypeId"] = $newCTID
                    $_.Update()
                    $_.File.CheckIn("Content type changed to " + $newCT.Name, 1)
                }
                else
                {
                    write-host "File" $_.Name "is checked out to" $_.File.CheckedOutByUser.ToString() "and cannot be modified"
                }
            }
            else
            {
                write-host "File" $_.Name "is associated with the content type" $_.ContentType.Name "and shall not be modified"
            }
        }
    }
    else
    {
        write-host "One of the content types specified has not been attached to the list"$list.Title
    }
    $web.Dispose()
}

Once the script has been run, you can use it by typing the following command:

Reset-SPFileContentType –WebUrl <Site URL> –ListName <Document library display name> –OldCTName <Content type to be replaced> –NewCTName <Content type to replace it with>

For example, the following command will step through all files in a document library called “Shared Documents” from the site http://portal/team, and change all documents associated with the “Document” content type to one called “Sales Document”:

Reset-SPFileContentType –WebUrl “http://portal/team” –ListName “Shared Documents” –OldCTName “Document” –NewCTName “Sales Document”

Note that the new content type must be associated with the list before you run the command – the script will not attach it for you (I’ll be providing scripts for attaching and removing content types on lists in future posts).

A potential issue with performing this sort of change is that you may lose some column values during the content type move – even if the same columns exist on both the old and new content type. I did some simple testing with the standard “Title” column, a custom text column, and a choice column and values were successfully retained when I changed the content type – even on non-Microsoft Office documents. However, as I cannot guarantee this will be the case with all columns or column types, I strongly recommend that you attempt the move in a test document library or development environment prior to running the script for real.