add netrw support. resolves #31.

autoload/airline.vim

@@ -67,6 +67,8 @@ function! s:apply_window_overrides()
     let w:airline_section_b = ''
     let w:airline_section_c = bufname(winbufnr(winnr()))
   endif
+
+  call airline#extensions#apply_window_overrides()
 endfunction
 
 function! airline#update_externals()
@@ -106,13 +108,13 @@ function! airline#update_statusline(active)
     let sl.=l:info_sep_color
     let sl.=g:airline_left_sep
     let sl.=l:status_color.' '.s:get_section('c').' '
-    let sl.=s:get_section('gutter') != ''
+    let sl.=exists('w:airline_section_gutter')
           \ ? s:get_section('gutter')
-          \ : '%#warningmsg#'.g:airline_externals_syntastic.l:status_color."%<%=".l:file_flag_color."%{&ro ? g:airline_readonly_symbol : ''}".l:status_color
+          \ : '%#warningmsg#'.g:airline_externals_syntastic.l:file_flag_color."%{&ro ? g:airline_readonly_symbol : ''}".l:status_color
   else
-    let sl.=' %f%<%='
+    let sl.=' %f'
   endif
-  let sl.=' '.s:get_section('x').' '
+  let sl.='%<%= '.s:get_section('x').' '
   let sl.=l:info_sep_color
   let sl.=a:active ? g:airline_right_sep : g:airline_right_alt_sep
   let sl.=l:info_color

autoload/airline/extensions.vim

@@ -1,10 +1,7 @@
+let s:sections = ['a','b','c','gutter','x','y','z']
+
 function! airline#extensions#load()
   let g:unite_force_overwrite_statusline = 0
-  autocmd FileType unite
-        \ let w:airline_section_a = 'Unite'
-        \ | let w:airline_section_b = unite#get_status_string()
-        \ | call airline#update_statusline(1)
-        \ | unlet w:airline_section_a | unlet w:airline_section_b
 
   if exists('g:loaded_ctrlp') && g:loaded_ctrlp
     call airline#extensions#ctrlp#load_ctrlp_hi()
@@ -14,3 +11,27 @@ function! airline#extensions#load()
           \ }
   endif
 endfunction
+
+function! s:empty_sections()
+  for section in s:sections
+    let w:airline_section_{section} = ''
+  endfor
+endfunction
+
+function! airline#extensions#apply_window_overrides()
+  for section in s:sections
+    silent! unlet w:airline_section_{section}
+  endfor
+
+  if &ft == 'netrw'
+    let w:airline_section_a = 'netrw'
+    let w:airline_section_b = '%f'
+    let w:airline_section_c = ''
+    let w:airline_section_gutter = ''
+    let w:airline_section_x = ''
+  elseif &ft == 'unite'
+    call s:empty_sections()
+    let w:airline_section_a = 'Unite'
+    let w:airline_section_b = unite#get_status_string()
+  endif
+endfunction

plugin/airline.vim

@@ -21,7 +21,7 @@ call s:check_defined('g:airline_linecolumn_prefix', exists('g:airline_powerline_
 call s:check_defined('g:airline_paste_symbol', (exists('g:airline_powerline_fonts') ? ' ' : '').'PASTE')
 call s:check_defined('g:airline_theme', 'dark')
 call s:check_defined('g:airline_exclude_filenames', ['DebuggerWatch','DebuggerStack','DebuggerStatus'])
-call s:check_defined('g:airline_exclude_filetypes', ['netrw','diff','undotree','gundo','nerdtree','tagbar'])
+call s:check_defined('g:airline_exclude_filetypes', ['diff','undotree','gundo','nerdtree','tagbar'])
 
 call s:check_defined('g:airline_mode_map', {
       \ 'n'  : 'NORMAL',