When typing in a link instead of copy-pasting it, link is somehow validated in the background and if it does not seem like a link - clicking a green Link button will do nothing. This is a bit confusing, since the color green suggest that the button is "good-to-go". However, clicking on it does not trigger any action - there is no feedback to the user (error message?).
It gets even more confusing, when users are inserting seemingly valid link like www.google.com - however, without http prefix this is not a link according to trix.

Thanks, @athelas64. I agree Trix could help format URLs by adding http:// when necessary.
Trix's default CSS includes styles that highlight the field when invalid. You can see them in action at https://trix-editor.org:

Basecamp (as seen in your screenshot) uses its own set of styles that don't currently handle the invalid state. /cc @early
this is the hack I'm using right now:
$trixToolbar = @$('trix-toolbar')
$urlInput = $trixToolbar.find('.link_url_fields input').eq(0)
normalizeWebEmbedURL = ->
if url = MY_STUFF_TO_ADD_HTTP($urlInput.val())
$urlInput.val(url)
return
$trixToolbar.find('.link_url_fields input[type="button"]').eq(0).on('click', normalizeWebEmbedURL)
$urlInput.on('keydown', (e) ->
normalizeWebEmbedURL() if e.keyCode is 13 # => 'enter'
return
)
Ooof, yeah we should highlight that in Basecamp. I'll take a look.
@early Wow, I see highlighting in Basecamp already works. Nice job :+1:
Thanks @early!
I spent so long thinking that the linking functionality didn't work, and trying to fix it, only to read this thread and realising it was working fine, I just wasn't adding the http. Call my myself a developer!