unite custom action(dirdiff)

unite_dirdiff.vim

NeoBundle 'vim-scripts/DirDiff.vim.git'

let dirdiff_action = {
            \ 'description' : 'DirDiff with the other candidate',
            \ 'is_selectable' : 1,
            \ }

function! dirdiff_action.func(candidates)
    if len(a:candidates) == 2
        " :DirDiff with selected candidates
        call unite#util#smart_execute_command('tabnew', '')
        execute ':DirDiff ' . a:candidates[0].action__path . ' ' . a:candidates[1].action__path
    endif
endfunction

call unite#custom_action('directory', 'dirdiff', dirdiff_action)