1 # Nick's web site: css_clean_selectors filter. Remove unnecessary whitespace
2 # from CSS selectors as this improves compatibility with old versions of IE.
4 # Copyright © 2020 Nick Bowler
6 # This program is free software: you can redistribute it and/or modify
7 # it under the terms of the GNU General Public License as published by
8 # the Free Software Foundation, either version 3 of the License, or
9 # (at your option) any later version.
11 # This program is distributed in the hope that it will be useful,
12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 # GNU General Public License for more details.
16 # You should have received a copy of the GNU General Public License
17 # along with this program. If not, see <https://www.gnu.org/licenses/>.
19 class CssCleanSelectorsFilter < Nanoc::Filter
20 identifier :css_clean_selectors
24 def run(content, params = {})
25 tree = Crass.parse(content, params)
27 queue = Array.new(tree)
28 while i = queue.shift do
29 if i[:node] == :at_rule
31 when "media", "supports"
32 # Re-parse the block as a list of rules.
33 s = Crass::Parser.stringify(i[:block])
34 i[:block] = Crass::Parser.parse_rules(s, params)
40 ts = i[:selector][:tokens]
42 next if ts[i].nil? or ts[i][:node] != :delim
43 next if ts[i][:value] == '*'
46 # keep whitespace before class selectors
47 next if ts[i][:value] == '.' and ts[i-1][:node] == :whitespace
50 ts[i-1] = nil if ts[i-1] and ts[i-1][:node] == :whitespace
51 ts[i+1] = nil if ts[i+1] and ts[i+1][:node] == :whitespace
56 return Crass::Parser.stringify(tree)