add ability to have no content to more cardtypes



One often wants to soft format a relative inclusion to be a date, file or image. If it's a date, then the inclusion will always be created with whetever date the +*rform happened to have when it was created.


File and image cards are able to be blank initially, but if someone uploads a file or image to them by accident there's no way to get them back to being blank.




Date will be handled as part of upgrade Date cardtype.

Vague memory that we thought a workaround was to change cardtypes and blank out the card's content, but this doesn't work. See and*rform

  --John Abbe.....Sat Aug 22 15:23:47 -0700 2009

I think as of wagn 1.8 this will be in a good state. I don't think a "revert to blank" button makes any sense -- interface noise. But the date editor is now more flexible (it's the default jquery ui date editor) and you can work around files and images by changing type away and back or by deleting and recreating.

  --Ethan McCutchen.....Thu Dec 01 15:16:01 -0800 2011