Power Apps : Clear Date, Person, Choice, Managed Metadata field values in edit form of SharePoint List/Library

SharePoint sometimes surprisingly lacks very basic operations like clearing up a choice, date and other lookup fields in the edit form. By default, when you edit an item using a power apps customised form, the values of the special fields like date, choice , managed metadata, person or group field etc cannot be cleared. If you remove the value from the input control and save the item, the old value will still persist. This post is about a simple technique using powerapps to clear the values of any special field in SharePoint.