wro4j-core/src/main/java/ro/isdc/wro/model/resource/processor/impl/css/CssVariablesProcessor.java
private String replaceVariables(final String css, final Map<String, String> variables) {
    final StringBuffer sb = new StringBuffer();
    final Matcher m = PATTERN_VARIABLE_HOLDER.matcher(css);
    while (m.find()) {
      final String oldMatch = m.group();
      final String variableName = m.group(1);
      final String variableValue = variables.get(variableName);
      if (variableValue != null) {
        final String newReplacement = oldMatch.replace(oldMatch, variableValue);
        m.appendReplacement(sb, newReplacement.trim());
      } else {
        LOG.warn("No variable with name " + variableName + " was found!");
      }
    }
    m.appendTail(sb);
    return sb.toString();
  }
private String replaceVariables(final String css, final Map<String, String> variables) {
    final StringBuffer sb = new StringBuffer();
    final Matcher m = PATTERN_VARIABLE_HOLDER.matcher(css);
    while (m.find()) {
      final String oldMatch = m.group();
      final String variableName = m.group(1);
      final String variableValue = variables.get(variableName);
      if (variableValue != null) {
        final String newReplacement = oldMatch.replace(oldMatch, variableValue);
        m.appendReplacement(sb, newReplacement.trim());
      } else {
        LOG.warn("No variable with name " + variableName + " was found!");
      }
    }
    m.appendTail(sb);
    return sb.toString();
  }
Replace variables from css with provided variables map.

@param cleanCss
used to replace variable placeholders.
@param variables
map of variables used for substitution.
@return css with all variables replaced.