Whitelist instead of blacklist

[blasco]

I would like to enable the whitespaces highlighting in a few files, rather than blacklisting every single other file I would like to have a way to enable it to the few files that I want. Is there something like a whitelist, the opposite to

let g:better_whitespace_filetypes_blacklist=['<filetype1>', '<filetype2>', '<etc>',
                                        'diff', 'gitcommit', 'unite', 'qf', 'help']

How would I do it if I only want to enable it for "c" files for example

[Cimbali]

You can use autocommands for that. Just disable the plugin globally and enable it for the right filetypes:

let g:better_whitespace_enabled=0
au FileType c EnableWhitespace