SharePoint O365/Online Default value for Person or Group field with XML or CSOM

Question

I am trying to put a default user into a People or Group data type into a SharePoint Online list. Is this possible using CSOM or the XML definition?

This is what i have tried: -

XML

    <Field DisplayName="People" Name="theField" StaticName="theField" Type="User" UserSelectionMode="PeopleOnly" 
           ID="{63FD2388-BA5E-4BE4-B2BE-9406B02FD7D3}" Required="FALSE" Group="Group">
      <Default>1;#Joe Bloggs</Default>
    </Field>

CSOM

Microsoft.SharePoint.Client.User usr = clientContext.Web.EnsureUser(@"JoeBloggs");
clientContext.Load(usr);
clientContext.ExecuteQuery();

FieldUserValue defValue = new FieldUserValue();
defValue.LookupId = usr.Id;

theField.DefaultValue = defValue.ToString();
theField.Update();

Both tests make the field do this

Is this possible?

Thanks

Answer 1

Default values for People fields are not possible, either programmatically or via the UI.

You could fake the effect via a Remote Event Receiver, Webhook, or possibly a Flow.