Re: Undo framework

[Jody Goldberg <jody gnome org>]

On Mon, Sep 24, 2007 at 08:32:01PM +0200, Sven Neumann wrote:
> Hi,
> 
> On Mon, 2007-09-24 at 09:23 -0400, Jody Goldberg wrote:
> 
> > The 'transaction' refered to a mechanism for persisting the details
> > of each operation to a file.
> >     1) The options could be re-played in the case of failure.
> >     2) The data would provide useful hooks for auditing and
> >        validation.
> 
> This would certainly be useful but it is something different than an
> Undo system. An undo system stores information on how to undo an
> operation. This typically involves storing data and state information
> from before the operation is performed. This information allows you to
> undo the operation, but it typically doesn't allow you to replay it.

Undo comes with Redo, which is sufficient information to make a
replay a modification from a known state.