Convert stylesheet to SCSS and preprocess with SASS.

[homepage.git] / lib / css-clean-selectors.rb

diff --git a/lib/css-clean-selectors.rb b/lib/css-clean-selectors.rb
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+# Nick's web site: css_clean_selectors filter.  Remove unnecessary whitespace
+# from CSS selectors as this improves compatibility with old versions of IE.
+#
+# Copyright © 2020 Nick Bowler
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+class CssCleanSelectorsFilter < Nanoc::Filter
+    identifier :css_clean_selectors
+
+    require 'crass'
+
+    def run(content, params = {})
+        tree = Crass.parse(content, params)
+
+        queue = Array.new(tree)
+        while i = queue.shift do
+          if i[:node] == :at_rule
+            case i[:name]
+            when "media", "supports"
+              # Re-parse the block as a list of rules.
+              s = Crass::Parser.stringify(i[:block])
+              i[:block] = Crass::Parser.parse_rules(s, params)
+              queue += i[:block]
+            end
+          end
+
+          if i[:selector]
+            ts = i[:selector][:tokens]
+            ts.each_index do |i|
+                next if ts[i].nil? or ts[i][:node] != :delim
+                next if ts[i][:value] == '*'
+
+                ts[i-1] = nil if ts[i-1] and ts[i-1][:node] == :whitespace
+                ts[i+1] = nil if ts[i+1] and ts[i+1][:node] == :whitespace
+            end
+          end
+        end
+
+        return Crass::Parser.stringify(tree)
+    end
+end