add events DIFF_RENDER and DIFF_TYPES to add new diff renderer via plugin

[peterfromearth]

i would like to add a plugin which adds a new diff renderer using this external html renderer https://github.com/caxy/php-htmldiff

Therefore I need two more events

• DIFF_TYPES (used to add a new type to the dropdown list)
• DIFF_RENDER (used to output the new renderer)

You can find the plugin which uses the new events here https://github.com/peterfromearth/dokuwiki-plugin-htmldiff

[Klap-in]

There is a big refactor of the code under way of the revision en diff UI parts. I guess it is most practical to merge this after #3361

[peterfromearth]

@Klap-in thanks for the hint. I adopted the changes to be compatible with the pullRequest in this branch https://github.com/peterfromearth/dokuwiki/tree/revisionHandle3_event_diff (Diff: peterfromearth@f98e218?w=1)

Currently its not very optimal to insert a new renderer. Maybe you have some ideas to improve it.

[Klap-in]

Your proposal with two events, and the second one that wraps the default html output makes sense for me, but I assumed that you build a complete new diff view.
I react on that commit here:
peterfromearth@f98e218

I’m wondering if wrapping only the final step is really practical. I think it makes it not possible to change the header, so less flexible. 1c9523b

Replacing complete output html makes task of the plugin a bit bigger, and more flexible, the little bit of code duplication is fine for me. So I prefer peterfromearth@f98e218

[Klap-in]

Currently its not very optimal to insert a new renderer. Maybe you have some ideas to improve it.

you means this part: https://github.com/peterfromearth/dokuwiki-plugin-htmldiff/blob/f50d93986106138db15466413278ae3139264883/action.php#L66-L67
The use of p_wiki_xhtml() is fine here so far I know.