I have successfully created a feature in sharepoint that modifies the existing edit dialog and adds a custom button to it like this.
and I am aware that I can pass back data when the user clicks the custom button like this.
<CommandUIHandlers>
<CommandUIHandler Command="ActivateUser" CommandAction="/_layouts/MyFeature/MakeUserActive.aspx?ListID={ListId}&ItemID={ItemId}&ItemUrl={ItemUrl}&ListUrlDir={ListUrlDir}" />
</CommandUIHandlers>
As detailed here
I can now handle the list item and perform my required actions on it BUT given that this button has been added in the modify context (IE: Inside the sharepoint edit item dialog) what if you want to save changes to the data itself?
To me it seems like using your custom button would always mean losing any changes the user has made to the data. Is there a way around this?