move updating external values into extensions

autoload/airline.vim

@@ -52,22 +52,6 @@ function! airline#highlight(modes)
   endfor
 endfunction
 
-function! airline#update_externals()
-  let g:airline_externals_bufferline = g:airline_enable_bufferline && exists('*bufferline#get_status_string')
-        \ ? '%{bufferline#refresh_status()}'.bufferline#get_status_string() : "%f%m"
-  let g:airline_externals_syntastic = g:airline_enable_syntastic && exists('*SyntasticStatuslineFlag')
-        \ ? '%{SyntasticStatuslineFlag()}' : ''
-  let g:airline_externals_branch = g:airline_enable_branch
-        \ ? (exists('*fugitive#head') && strlen(fugitive#head()) > 0
-          \ ? g:airline_branch_prefix.fugitive#head()
-          \ : exists('*lawrencium#statusline') && strlen(lawrencium#statusline()) > 0
-            \ ? g:airline_branch_prefix.lawrencium#statusline()
-            \ : '')
-        \ : ''
-  let g:airline_externals_tagbar = g:airline_enable_tagbar && exists(':Tagbar')
-        \ ? '%(%{tagbar#currenttag("%s","")} '.g:airline_right_alt_sep.' %)' : ''
-endfunction
-
 " for 7.2 compatibility
 function! s:getwinvar(winnr, key, ...)
   let winvals = getwinvar(a:winnr, '')
@@ -102,7 +86,7 @@ function! s:get_statusline(winnr, active)
     let gutter = s:getwinvar(a:winnr, 'airline_section_gutter', get(g:, 'airline_section_gutter', ''))
     let sl.=gutter != ''
           \ ? gutter
-          \ : '%#warningmsg#'.g:airline_externals_syntastic.l:file_flag_color."%{&ro ? g:airline_readonly_symbol : ''}".l:status_color
+          \ : g:airline_externals_syntastic.l:file_flag_color."%{&ro ? g:airline_readonly_symbol : ''}".l:status_color
   else
     let sl.=l:status_color.' %f%m'
   endif

autoload/airline/extensions.vim

@@ -9,6 +9,22 @@ function! airline#extensions#apply_left_override(section1, section2)
   let w:airline_left_only = 1
 endfunction
 
+function! airline#extensions#update_external_values()
+  let g:airline_externals_bufferline = g:airline_enable_bufferline && exists('*bufferline#get_status_string')
+        \ ? '%{bufferline#refresh_status()}'.bufferline#get_status_string() : "%f%m"
+  let g:airline_externals_syntastic = g:airline_enable_syntastic && exists('*SyntasticStatuslineFlag')
+        \ ? '%#warningmsg#%{SyntasticStatuslineFlag()}' : ''
+  let g:airline_externals_branch = g:airline_enable_branch
+        \ ? (exists('*fugitive#head') && strlen(fugitive#head()) > 0
+          \ ? g:airline_branch_prefix.fugitive#head()
+          \ : exists('*lawrencium#statusline') && strlen(lawrencium#statusline()) > 0
+            \ ? g:airline_branch_prefix.lawrencium#statusline()
+            \ : '')
+        \ : ''
+  let g:airline_externals_tagbar = g:airline_enable_tagbar && exists(':Tagbar')
+        \ ? '%(%{tagbar#currenttag("%s","")} '.g:airline_right_alt_sep.' %)' : ''
+endfunction
+
 function! airline#extensions#apply_window_overrides()
   if &buftype == 'quickfix'
     let w:airline_section_a = 'Quickfix'
@@ -108,7 +124,10 @@ function! airline#extensions#load()
     let g:bufferline_separator = ' '
   endif
 
+  call add(g:airline_window_override_funcrefs, function('airline#extensions#update_external_values'))
   call add(g:airline_window_override_funcrefs, function('airline#extensions#apply_window_overrides'))
   call add(g:airline_exclude_funcrefs, function('airline#extensions#is_excluded_window'))
+
+  call airline#extensions#update_external_values()
 endfunction
 

plugin/airline.vim

@@ -51,7 +51,6 @@ function! s:on_window_changed()
   let s:active_winnr = winnr()
   if !s:airline_initialized
     call airline#extensions#load()
-    call airline#update_externals()
     call airline#load_theme(g:airline_theme)
     call s:check_defined('g:airline_section_a', '%{g:airline_current_mode_text}')
     call s:check_defined('g:airline_section_b', '%{g:airline_externals_branch}')
@@ -86,9 +85,9 @@ endfunction
 command! -nargs=? -complete=customlist,<sid>get_airline_themes AirlineTheme call <sid>airline_theme(<f-args>)
 
 augroup airline
-  au!
+  autocmd!
   autocmd ColorScheme * call airline#highlight(['normal'])
-  autocmd WinEnter,BufWinEnter,FileType,BufUnload * call <sid>on_window_changed()
+  autocmd WinEnter,BufWinEnter,FileType,BufUnload,ShellCmdPost *
-  autocmd ShellCmdPost * call airline#update_externals()
+        \ call <sid>on_window_changed()
   autocmd CursorMoved * call <sid>sync_active_winnr()
 augroup END