Javacript as Webpart to change Content Types

Question

I am not allowed to change the Content Type of a file using the Quick Edit.

I was wondering if there is any JavaScript code that I can add as a Web Part to the document Library.

This code should change the content type of multiple files.

Answer 1

For SharePoint Online, I suggest you change the content type using PnP Powershell.

#Set Variables
$SiteURL = "https://tenant.sharepoint.com/sites/projects"
$ListName = "Project Proposal"
$OldContentTypeName = "Crescent Proposal V1"
$NewContentTypeName = "Crescent Project Proposal V2"

#Connect to PNP Online
Connect-PnPOnline -Url $SiteURL -Credentials (Get-Credential)

#Get the New Content Type from the List
$NewContentType = Get-PnPContentType -List $ListName | Where {$_.Name -eq $NewContentTypeName}

#Get List Items of Old content Type
$ListItems = Get-PnPListItem -List $ListName -Query "<Query><Where><Eq><FieldRef Name='ContentType'/><Value Type='Computed'>$OldContentTypeName</Value></Eq></Where></Query>"
Write-host "Total Number of Items with Old Content Type:"$ListItems.count

ForEach($Item in $ListItems)
{
    #Change the Content Type of the List Item
    Set-PnPListItem -List $ListName -Identity $Item -ContentType $NewContentType
}

Reference: SharePoint Online: Change Content Type of List Items using PowerShell

If you can't use PowerShell, we can also use JSOM to achieve it. The following code snippet for your reference.

<script type="text/javascript" language="javascript">
ExecuteOrDelayUntilScriptLoaded(runCode, "sp.js");
function runCode(){   
    var contenttypeId = '0x01040005B1FCA568800F4FB4162C7A09742E67';
    var lisTitle = "TestNewList";
    var listitemId = 1;

    UpdateListItem(lisTitle, listitemId, contenttypeId);
}
function UpdateListItem(listTitle, listitemId, contenttypeId) {
    var clientContext = new SP.ClientContext();
    oList = clientContext.get_web().get_lists().getByTitle(listTitle);
    oListItem = oList.getItemById(listitemId);
    oListItem.set_item('ContentTypeId', contenttypeId);
    oListItem.update();
    clientContext.load(oListItem, 'Id', 'Title', 'ContentTypeId');
    clientContext.executeQueryAsync(
        Function.createDelegate(this, function() {
            var listsInfo = '';
            listsInfo += oListItem.get_item('Title') + '\t' + oListItem.get_item('ContentTypeId');
            alert(listsInfo.toString());
        }),
        Function.createDelegate(this, function(sender, args) {
            alert('Request failed. ' + args.get_message() + '\n' + args.get_stackTrace());
        })
    );
}
</script>