Make navbar search input default to searching wiki when user is on wiki pages?

[beernuts]

As per the title, is there any way to make the search box default to ONLY searching wiki content when the user is on a wiki page? I know you can visit the search single content type form to select Wiki Content as your search area, but how can we update the navbar template to do this automatically when a user is on a VW page?

[pegasus]

In VaultWiki 4, when you are on a wiki page, you can use the search field in the sidebar for searching only within the wiki.

From what I understand, only the XenForo platform offers contextual options for the navbar search because the search field has some drop-down info to let the user know what is being searched. vBulletin 4 doesn't have this (vBulletin 3 partially did), so any forcible change like that could be jarring to the user.