doc/todo/preview_changes.mdwn



When editing a page, it would help to have a "preview changes" or "show diff" button, which brings up a diff from the current page content to the proposed new page content. --[[JoshTriplett]]
Some discussion from the main [[/index/discussion]] page:

It would be nice to be able to have a button to show "Differences" (or "Show Diff") when
editing a page. Is that an option that can be enabled?

It's doable, it could even be done by a [[todo/plugin]], I think.
--[[Joey]]


I need help with this. Supposedly, such a plugin would provide a formbuilder_setup
hook which would add the button, and a cgi hook which would interecept
"Show Diff" clicks. This would show a diff between
titlepage(possibly_foolish_untaint($form->field("page")))
and the provided $form->field("editcontent").
But:

How could the case of concurrent editing be handled ?
Especially as (I think) only the RCS backend can know that
this has happened.
Doing the formbuilder trick for adding a button needs the following
patch. (note that this is not the only template which has its submit
buttons hardcoded; is this supposed to work around something?)
Coercing editpage() into showing the edit form again rather that
saving the page would be tricky and hackish to do from a module;
maybe this would better be implemented directly in showpage?


--[[JeremieKoenig]]