I just saw that when using the preview plugins, markdown links like [caption](link/to/file.md) are underlined in the Kate editor. It would be nice when one could follow such a link to its local file, e.g. by a context menu item ("Open file: <name of the file>" or by Ctrl+Click on the link). Related: https://bugs.kde.org/show_bug.cgi?id=385897 (click on URLs in the Webpreview)
This seems not a feature request for the preview plugin, but a more general request which might be interesting also without a preview (e.g. following relative header files in source files, include files in tex files, relative urls in static html pages etc.). It possibly could be implemented in co-operation with ksyntaxhighlighter: perhaps there could be some semantic tagging via the formatting rules to mark (relative) urls as such, and Kate/KTextEditor could then offer some url handling next to using the right color/font. The preview plugins itself is dumb when it comes to any formats, and the kparts it uses for rendering have (currently) no clue they are used together with a text document view, so delegating this task to them would require first to teach them a lot about KTextEditor and developing some generic interfaces.
Dear user, this wish list item is now closed, as it wasn't touched in the last year and no contributor stepped up to implement it. The Kate/KTextEditor team is small and we can just try to keep up with fixing bugs. Therefore wishes that show no activity for a years or more will be closed from now on to keep at least a bit overview about 'current' wishs of the users. If you want your feature to be implemented, please step up to provide some patch for it. If you think it is really needed, you can reopen your request, but keep in mind, if no new good arguments are made and no people get attracted to help out to implement it, it will expire in a year again. We have a nice website https://kate-editor.org that provides all the information needed to contribute, please make use of it. Patches can be handed in via https://phabricator.kde.org/differential/ Greetings Christoph Cullmann