Sorry, you won't be able to do this with the current API as it's pretty crappy: http://our.umbraco.org/forum/developers/extending-umbraco/2275-beforepublish-and-beforesave-event-handlers

I think the only option you have is, in the AfterSave event, do a rollback in the to the previous version if validation fails. I found this, not sure if it works (d is the sender, your document). 

d.RollBack(new Guid(d.Version), new User(0));

And you can get the already saved values by just getting the document again:

var savedDoc = new Document(d.Id);

I've never tried this but it might just work.

Many thanks for your reply, very much appreciated.

I will look at using your suggested way of performing a rollback, since that would be a lifesaver for a feature we are looking to implement.

Thanks :)

If you're on 4.11.x then the upgrade to v6 should be relatively painless, we'll release it soon!

In v6 the API is much better and you can do whatever you want before values are actually saved. :)

I gave the following a shot

private Guid prevVersion;

private void OnBeforeDocumentSave(Document sender, SaveEventArgs e)
{
    this.prevVersion = sender.Version;
}

private void CheckForNationalNodeIdentifier(object sender, SaveEventArgs e)
{
    var doc = sender as Document;

    if(!this.documentValidator.DocumentValid(doc))
    {
        var currentUser = // Get current user.
        doc.RollBack(this.prevVersion, currentUser);
    }
}

But this fails to rollback to the previous version because the Guid values of "prevVersion" and "doc.Version" are the same.

Again, I might be going around this wrong way - I may have misunderstood about picking up the old version ID for the document?

Neh, as I said I didn't test this, so I'm not sure if and how it works. You might want to use d.GetVersions() then, something like (assuming the previous version is the last on in the list):

var count = d.GetVersions().Count();
this.prevVersion = d.GetVersions().Skip(count - 1).Take(1).Single().Version;

Apologies for missing GetVersions(), didn't spot that method initially.

That works a charm, as I can now rollback to the previous version by doing doc.GetVersions().First().Version.

Thanks for your help.

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