I have a workspace using a ChangeDetector to maintain data in a SharePoint Online list, using a Microsoft SharePoint Server List writer (we are blocked from using the Graph API, so the Microsoft SharePoint Online List reader/writer are not options for us).
When a value has been written to a field in the list but is later removed in the source/revised data, the ChangeDetector recognizes this and sends either a null or blank/empty value to the writer, without error.
But, the null/empty/blank value is not actually written or accepted, and the stale value persists.
I’ve found that if I use a NullAttributeMapper and map Empty, Missing, and Null values to a New Value and set that to a single space character, that SharePoint actually writes the null/blank value over the existing value. For anyone trying to do the same, this might be an important point.
The issue that I’ve run into is that Date/DateTime-type fields will not accept a space as input. I’ve tried writing in 00000000 and it is also rejected. I gave an FME DateTime-related function invalid parameters so that it produced a null value, but of course that did not work either.
Any thoughts on how to overwrite an existing value in a Date/Time field in a SharePoint list to a null/blank/empty value?
The work-around is to go and delete the value manually in the 365 web interface, but that is not ideal.
Appreciate any input on possible solutions.