Buffer-local stripping of whitespace

Author: Cimbali

README.md

@@ -34,8 +34,10 @@ Whitespace highlighting is enabled by default, with a highlight color of red.
     highlight ExtraWhitespace ctermbg=<desired_color>
     ```
 
-*  To toggle whitespace highlighting on/off, call:
+*  To enable/disable/toggle whitespace highlighting in a buffer, call one of:
     ```
+    :EnableWhitespace
+    :DisableWhitespace
     :ToggleWhitespace
     ```
 
@@ -51,7 +53,7 @@ Whitespace highlighting is enabled by default, with a highlight color of red.
 
     *  The level `soft` will use syntax based highlighting, so there shouldn't be
         a performance hit like with the `hard` option.  The drawback is that this
-        highlighting will have a lower priority and may be overwritten by higher
+        highlighting will have a lower priority and may be overwritten by higher 
         priority highlighting.
 
 *  To re-enable highlighting for the current line in normal mode:
@@ -67,16 +69,18 @@ Whitespace highlighting is enabled by default, with a highlight color of red.
     the file that it cleans, either give it a range or select a group of lines
     in visual mode and then execute it.
 
-*  To enable/disable stripping of extra whitespace on file save, call:
+*  To enable/disable stripping of extra whitespace on file save for a buffer, call one of:
     ```
+    :EnableStripWhitespaceOnSave
+    :DisableStripWhitespaceOnSave
     :ToggleStripWhitespaceOnSave
     ```
     This will strip all trailing whitespace everytime you save the file for all file types.
 
     *  If you want this behaviour by default for all filetypes, add the following to your `~/.vimrc`:
 
         ```
-        autocmd BufEnter * EnableStripWhitespaceOnSave
+        let g:strip_whitespace_on_save = 1
         ```
 
         For exceptions of all see ```g:better_whitespace_filetypes_blacklist```.
@@ -85,13 +89,11 @@ Whitespace highlighting is enabled by default, with a highlight color of red.
         the following to your `~/.vimrc`:
 
         ```
-        autocmd FileType <desired_filetypes> autocmd BufEnter <buffer> EnableStripWhitespaceOnSave
+        autocmd FileType <desired_filetypes> EnableStripWhitespaceOnSave
         ```
 
         where `<desired_filetypes>` is a comma separated list of the file types you want
         to be stripped of whitespace on file save ( ie. `javascript,c,cpp,java,html,ruby` )
-        Note that `<buffer>` is a keyword here denoting operation on the current buffer and
-        should stay just as it appears in the line above.
 
 *  To disable this plugin for specific file types, add the following to your `~/.vimrc`:
     ```
@@ -109,6 +111,15 @@ Whitespace highlighting is enabled by default, with a highlight color of red.
                                             'diff', 'gitcommit', 'unite', 'qf', 'help']
     ```
 
+    This blacklist can be overriden on a per-buffer basis using the buffer toggle enable and
+    disable commands presented above. For example:
+    ```vim
+    " highlight whitespace in markdown files, though stripping remains disabled by the blacklist
+    :autocmd FileType markdown EnableWhitespace
+    " Do not modify kernel files, even though their type is not blacklisted and highlighting is enabled
+    :autocmd BufRead /usr/src/linux* DisableStripWhitespaceOnSave
+    ```
+
 *  To enable verbose output for each command, set verbosity in your `.vimrc`:
     ```
     let g:better_whitespace_verbosity=1

plugin/better-whitespace.vim

@@ -163,21 +163,22 @@ endfunction
 
 " Strip whitespace on file save
 function! s:EnableStripWhitespaceOnSave()
-    let g:strip_whitespace_on_save = 1
+    let b:strip_whitespace_on_save = 1
     call <SID>Echo("Strip Whitespace On Save: Enabled")
     call <SID>SetupAutoCommands()
 endfunction
 
 " Don't strip whitespace on file save
 function! s:DisableStripWhitespaceOnSave()
-    let g:strip_whitespace_on_save = 0
+    let b:strip_whitespace_on_save = 0
     call <SID>Echo("Strip Whitespace On Save: Disabled")
     call <SID>SetupAutoCommands()
 endfunction
 
 " Strips whitespace on file save
 function! s:ToggleStripWhitespaceOnSave()
-    if g:strip_whitespace_on_save == 1
+    call <SID>ShouldSkipHighlight()
+    if b:strip_whitespace_on_save == 1
         call <SID>DisableStripWhitespaceOnSave()
     else
         call <SID>EnableStripWhitespaceOnSave()
@@ -186,7 +187,12 @@ endfunction
 
 " Determines if whitespace highlighting should currently be skipped
 function! s:ShouldSkipHighlight()
-    return &buftype == 'nofile' || index(g:better_whitespace_filetypes_blacklist, &ft) >= 0
+    if !exists('b:better_whitespace_enabled')
+        let b:better_whitespace_enabled = &buftype != 'nofile' && index(g:better_whitespace_filetypes_blacklist, &ft) == -1
+    endif
+    if !exists('b:strip_whitespace_on_save')
+        let b:strip_whitespace_on_save = b:better_whitespace_enabled && g:strip_whitespace_on_save
+    endif
 endfunction
 
 " Run :StripWhitespace to remove end of line whitespace
@@ -210,12 +216,12 @@ command! -nargs=* CurrentLineWhitespaceOff call <SID>CurrentLineWhitespaceOff( <
 command! CurrentLineWhitespaceOn call <SID>CurrentLineWhitespaceOn()
 
 " Process auto commands upon load, update local enabled on filetype change
-autocmd FileType * let b:better_whitespace_enabled = !<SID>ShouldSkipHighlight() | call <SID>SetupAutoCommands()
+autocmd FileType * call <SID>ShouldSkipHighlight() | call <SID>SetupAutoCommands()
 autocmd WinEnter,BufWinEnter * call <SID>SetupAutoCommands()
 autocmd ColorScheme * call <SID>WhitespaceInit()
 
 function! s:PerformMatchHighlight(pattern)
-    call s:InitVariable('b:better_whitespace_enabled', !<SID>ShouldSkipHighlight())
+    call <SID>ShouldSkipHighlight()
     if b:better_whitespace_enabled == 1
         exe 'match ExtraWhitespace "' . a:pattern . '"'
     else
@@ -225,7 +231,7 @@ endfunction
 
 function! s:PerformSyntaxHighlight(pattern)
     syn clear ExtraWhitespace
-    call s:InitVariable('b:better_whitespace_enabled', !<SID>ShouldSkipHighlight())
+    call <SID>ShouldSkipHighlight()
     if b:better_whitespace_enabled == 1
         exe 'syn match ExtraWhitespace excludenl "' . a:pattern . '"'
     endif
@@ -285,8 +291,8 @@ function! <SID>SetupAutoCommands()
             endif
         endif
 
-        " Strip whitespace on save if enabled
-        if g:strip_whitespace_on_save == 1
+        " Strip whitespace on save if enabled.
+        if (exists('b:strip_whitespace_on_save') ? b:strip_whitespace_on_save : g:strip_whitespace_on_save) == 1
             autocmd BufWritePre * call <SID>StripWhitespace( 0, line("$") )
         endif