extract buffer name logic into a formatter.

hold off on deprecation warnings for now...

autoload/airline/deprecation.vim

@@ -19,11 +19,13 @@ function! airline#deprecation#check()
         \ [ 'g:airline_enable_branch', 'g:airline#extensions#branch#enabled' ],
         \ [ 'g:airline_enable_bufferline', 'g:airline#extensions#bufferline#enabled' ],
         \ [ 'g:airline_enable_syntastic', 'g:airline#extensions#syntastic#enabled' ],
-        \ [ 'g:airline#extensions#tabline#fnamemod', 'g:airline#extensions#tabline#fnamefunc' ],
+        \ [ 'g:airline#extensions#tabline#fnamemod', 'g:airline#extensions#tabline#formatter' ],
         \ ]
   for test in tests
     if exists(test[0])
-      echom printf('The variable %s is deprecated and may not work in the future. It has been replaced with %s. Please read the documentation.', test[0], test[1])
+      let max = winwidth(0) - 16
+      let msg = printf('The variable %s is deprecated and may not work in the future. It has been replaced with %s. Please read the documentation.', test[0], test[1])
+      echom msg[:max].'...'
     endif
   endfor
 endfunction

autoload/airline/extensions/tabline.vim

@@ -1,13 +1,10 @@
 " MIT License. Copyright (c) 2013 Bailey Ling.
 " vim: et ts=2 sts=2 sw=2
 
-let s:fnamefunc = get(g:, 'airline#extensions#tabline#fnamefunc', 'airline#extensions#tabline#fname_func')
+let s:formatter = get(g:, 'airline#extensions#tabline#formatter', 'default')
 let s:excludes = get(g:, 'airline#extensions#tabline#excludes', [])
 let s:tab_nr_type = get(g:, 'airline#extensions#tabline#tab_nr_type', 0)
 let s:show_buffers = get(g:, 'airline#extensions#tabline#show_buffers', 1)
-let s:buf_nr_show = get(g:, 'airline#extensions#tabline#buffer_nr_show', 0)
-let s:buf_nr_format = get(g:, 'airline#extensions#tabline#buffer_nr_format', '%s: ')
-let s:buf_modified_symbol = g:airline_symbols.modified
 
 let s:builder_context = {
       \ 'active'        : 1,
@@ -82,30 +79,8 @@ function! airline#extensions#tabline#title(n)
   return airline#extensions#tabline#get_buffer_name(buflist[winnr - 1])
 endfunction
 
-function! airline#extensions#tabline#fname_func(name)
-  let fmod = get(g:, 'airline#extensions#tabline#fnamemod', ':p:.')
-  return substitute(fnamemodify(a:name, fmod), '\w\zs.\{-}\ze\/', '', 'g')
-endfunction
-
 function! airline#extensions#tabline#get_buffer_name(nr)
-  let _ = ''
-  let name = bufname(a:nr)
-
-  if s:buf_nr_show
-    let _ .= printf(s:buf_nr_format, a:nr)
-  endif
-
-  if empty(name)
-    let _ .= '[No Name]'
-  else
-    let _ .= call(s:fnamefunc, [name])
-  endif
-
-  if getbufvar(a:nr, '&modified') == 1
-    let _ .= s:buf_modified_symbol
-  endif
-
-  return _
+  return airline#extensions#tabline#formatters#{s:formatter}(a:nr)
 endfunction
 
 function! s:get_buffer_list()

autoload/airline/extensions/tabline/formatters.vim

@@ -0,0 +1,29 @@
+" MIT License. Copyright (c) 2013 Bailey Ling.
+" vim: et ts=2 sts=2 sw=2
+
+let s:buf_nr_format = get(g:, 'airline#extensions#tabline#buffer_nr_format', '%s: ')
+let s:buf_nr_show = get(g:, 'airline#extensions#tabline#buffer_nr_show', 0)
+let s:buf_modified_symbol = g:airline_symbols.modified
+
+function! airline#extensions#tabline#formatters#default(bufnr)
+  let _ = ''
+
+  if s:buf_nr_show
+    let _ .= printf(s:buf_nr_format, a:bufnr)
+  endif
+
+  let name = bufname(a:bufnr)
+  let fmod = get(g:, 'airline#extensions#tabline#fnamemod', ':p:.')
+  if empty(name)
+    let _ .= '[No Name]'
+  else
+    let _ .= substitute(fnamemodify(name, fmod), '\w\zs.\{-}\ze\/', '', 'g')
+  endif
+
+  if getbufvar(a:bufnr, '&modified') == 1
+    let _ .= s:buf_modified_symbol
+  endif
+
+  return _
+endfunction
+

doc/airline.txt

@@ -305,16 +305,6 @@ virtualenv <https://github.com/jmcantrell/vim-virtualenv>
 * enable/disable displaying buffers with a single tab. >
   let g:airline#extensions#tabline#show_buffers = 1
 <
-* defines a function for how to format the file name. >
-  " the default renders /foo/bar/file.txt => /f/b/file.txt
-  let g:airline#extensions#tabline#fnamefunc
-
-  " here's a simple example to show only the file name:
-  function! MyFileFormat(file)
-    return fnamemodify(a:file, ':t')
-  endfunction
-  let g:airline#extensions#tabline#fnamefunc = 'MyFileFormat'
-<
 * configure filename match rules to exclude from the tabline. >
   let g:airline#extensions#tabline#excludes = []
 <
@@ -322,12 +312,25 @@ virtualenv <https://github.com/jmcantrell/vim-virtualenv>
   let g:airline#extensions#tabline#tab_nr_type = 0 " # of splits (default)
   let g:airline#extensions#tabline#tab_nr_type = 1 " tab number
 <
+* defines the name of a formatter for how buffer names are displayed. >
+  let g:airline#extensions#tabline#formatter = 'default'
+
+  " here is how you can define a 'foo' formatter:
+  function! airline#extensions#tabline#formatters#foo(bufnr)
+    return fnamemodify(bufname(a:bufnr), ':t')
+  endfunction
+  let g:airline#extensions#tabline#formatter = 'foo'
+<
 * configure whether buffer numbers should be shown. >
   let g:airline#extensions#tabline#buffer_nr_show = 0
 <
+Note: this is only valid when the formatter is 'default'.
+
 * configure how buffer numbers should be formatted with |printf|. >
   let g:airline#extensions#tabline#buffer_nr_format = '%s: '
 <
+Note: this is only valid when the formatter is 'default'.
+
 * configure the minimum number of buffers needed to show the tabline. >
   let g:airline#extensions#tabline#buffer_min_count = 0
 <

plugin/airline.vim

@@ -6,7 +6,7 @@ if &cp || v:version < 702 || (exists('g:loaded_airline') && g:loaded_airline)
 endif
 let g:loaded_airline = 1
 
-autocmd VimEnter * call airline#deprecation#check()
+" autocmd VimEnter * call airline#deprecation#check()
 
 let s:airline_initialized = 0
 let s:airline_theme_defined = 0