Allow flag configuration of tagbar statusline string

autoload/airline/extensions/tagbar.vim

@@ -1,6 +1,8 @@
 " MIT License. Copyright (c) 2013 Bailey Ling.
 " vim: et ts=2 sts=2 sw=2
 
+let s:flags = get(g:, 'airline#extensions#tagbar#flags', '')
+
 " Arguments: current, sort, fname
 function! airline#extensions#tagbar#get_status(...)
   let builder = airline#builder#new({ 'active': a:1 })
@@ -18,7 +20,7 @@ endfunction
 
 function! airline#extensions#tagbar#currenttag()
   if get(w:, 'airline_active', 0)
-    return tagbar#currenttag('%s', '')
+    return tagbar#currenttag('%s', '', s:flags)
   endif
   return ''
 endfunction

doc/airline.txt

@@ -236,6 +236,9 @@ tagbar <https://github.com/majutsushi/>
 * enable/disable tagbar integration >
   let g:airline#extensions#tagbar#enabled = 1
 <
+* change how tags are displayed (:help tagbar-statusline) >
+  let g:airline#extensions#tagbar#flags = 'f'
+<
 -------------------------------------                          *airline-csv*
 csv.vim <https://github.com/chrisbra/csv.vim>