Timeline should show link to diff of wiki page changes

[Simon Willison]

When a wiki page has been changed, it's very useful to go to the page history for that page and view the diff between the current and previous versions. It would be great if the Trac timeline linked directly to this diff - not from the main link itself, but from an additional diff link listed with the timeline entry. Something a bit like this:

15:48 SandBox edited by anonymous (​diff)

[cboos]

The timeline entry is itself a link, so it's not possible to have a sublink.
The suggestion to link to the diff was actually already made in #239.

[Simon Willison]

Having looked over the code that deals with timeline events, it seems that it's not possible to include an extra link in the title. However, it should be possible to include the link in the comment field, producing something that looks like this:

16:44 SandBox edited by anonymous

removed spam (diff)

[cboos]

OK, that would be possible.

However, wouldn't it be better to actually always jump to the diff page,
unless it's a created page?
From there, its to jump to the latest version and, soon, the travel
to the previous/next changes (see #3250).

In the future, the Wiki diff page could even show the changes inline,
in the produced HTML.

[cboos]

Implements (diff) links, added after the change comment.

[cboos]

Here's what I think could be done:

1. attachment:wiki_timeline_event_diff_link-r3412.patch​ for now,
2. when/if we have the ability to render wiki page to HTML, with highlighted diffs (i.e. <INS> and <DEL> tags) remove the diff link and directly redirect to the full page with those highlighted diffs.

Tentatively scheduling for 0.10, if 1. is accepted.

[cmlenz]

I don't like the direct use of the Fragment class in that patch. Wouldn't something like the following work (not tested):

    if version > 1:
        diff_link = html.A('diff', href=href.wiki(
            name, action='diff', version=version,
            old_version=version-1))
        comment = Markup('%s (%s)', comment, diff_link)

[cboos]

Updated patch, using Markup instead of Fragment.

[cboos]

Well, no, that wouldn't work right now, as the Element gets first converted
to an unicode string, then gets escaped.
But of course, we could change that, and leave the Element untouched,
as we would do for Markup objects, which makes sense IMO.

Updated patch attachment:wiki_timeline_event_diff_link-r3417.patch​

[cboos]

Maybe this feature is not so useful anymore, as there's now the Last Change
link in the navigation links of the wiki page.

Please try out and tell me if you think the (diff) link would still be needed.

[cboos]

Well, after some more thought on this, I still think it's useful.

E.g. if I notice that the TracFaq page has been modified on p.e.c,
I don't really want to see it in full, rather I'm only interested
to see what has changed.

So even now with the Last Change link on the Wiki view page,
a quick (diff) link in the timeline has still its use for
by-passing a (sometimes long) rendering phase of the Wiki page.

Therefore, I implemented this in r3482.