How to set O365 PageLayout Associated Content Type field

Here is a code snippet to set your page layouts associated content type. This one was a bit weird when I first tried to set it.

 private static void SetPageLayoutMetadata(Web web, File uploadFile, string title, string publishingAssociatedContentType)
{
// Speficy that the page layout is a page layout and not a master page
var parentContentTypeId = ""0x01010007FF3E057FA8AB4AA42FCB67B453FFC100E214EEE741181F4E9F7ACC43278EE811""; //Page Layout
var gallery = web.GetCatalog(116);
web.Context.Load(gallery, g => g.ContentTypes);
web.Context.ExecuteQuery();

var contentTypeId = gallery.ContentTypes.FirstOrDefault(ct => ct.StringId.StartsWith(parentContentTypeId)).StringId;
var item = uploadFile.ListItemAllFields;
web.Context.Load(item);

item["ContentTypeId"] = contentTypeId;
item["Title"] = title;
item["PublishingAssociatedContentType"] = publishingAssociatedContentType;

item.Update();
web.Context.ExecuteQuery();
} 

Two important things:

• parentContentTypeId: This is the ID that tells O365 that this page layout is actually page layout, this is a static id which is defined in the code

• publishingAssociatedContentType: This is your actual content type to which you want to associate your page layout to: Example of the format:;#my content type name;#0x010100C568DB52D9D0A14D9B2FDCC96666E9F2007948130EC3DB064584E219954237AF3900242457EFB8B24247815D688C526CD44D00A3428808D7DE6A4RABF83921AFB25424;#
  • So the format should be in the following way:

public static String BuildPublishingAssociativeContentTypeId(ContentType contentType)
{
String contentTypeAssociativeID = null;
if(contentType != null)
{
contentTypeAssociativeID = String.Format(";#{0};#{1};#", contentType.Name, contentType.StringId);
}

return contentTypeAssociativeID;
}