five-bells-visualization/public/bower_components/polymer/src/lib/css-parse.html

Tool to visualize Five Bells payments

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<script>

/*
  Extremely simple css parser. Intended to be not more than what we need
  and definitely not necessarly correct =).
*/
(function() {

  // given a string of css, return a simple rule tree
  function parse(text) {
    text = clean(text);
    return parseCss(lex(text), text);
  }

  // remove stuff we don't care about that may hinder parsing
  function clean(cssText) {
    return cssText.replace(rx.comments, '').replace(rx.port, '');
  }

  // super simple {...} lexer that returns a node tree
  function lex(text) {
    var root = {start: 0, end: text.length};
    var n = root;
    for (var i=0, s=0, l=text.length; i < l; i++) {
      switch (text[i]) {
        case OPEN_BRACE:
          //console.group(i);
          if (!n.rules) {
            n.rules = [];
          }
          var p = n;
          var previous = p.rules[p.rules.length-1];
          n = {start: i+1, parent: p, previous: previous};
          p.rules.push(n);
          break;
        case CLOSE_BRACE: 
          //console.groupEnd(n.start);
          n.end = i+1;
          n = n.parent || root;
          break;
      }
    }
    return root;
  }

  // add selectors/cssText to node tree
  function parseCss(node, text) {
    var t = text.substring(node.start, node.end-1);
    node.cssText = t.trim();
    if (node.parent) {
      var ss = node.previous ? node.previous.end : node.parent.start;
      t = text.substring(ss, node.start-1);
      // TODO(sorvell): ad hoc; make selector include only after last ;
      // helps with mixin syntax
      t = t.substring(t.lastIndexOf(';')+1);
      node.selector = t.trim();
    }
    var r$ = node.rules;
    if (r$) {
      for (var i=0, l=r$.length, r; (i<l) && (r=r$[i]); i++) {
        parseCss(r, text);
      }  
    }
    return node;  
  }

  // stringify parsed css.
  function stringify(node, text) {
    text = text || '';
    // calc rule cssText
    var cssText = '';
    if (node.cssText || node.rules) {
      var r$ = node.rules;
      if (r$ && !hasMixinRules(r$)) {
        for (var i=0, l=r$.length, r; (i<l) && (r=r$[i]); i++) {
          cssText = stringify(r, cssText);
        }  
      } else {
        cssText = removeCustomProps(node.cssText).trim();
        if (cssText) {
          cssText = '  ' + cssText + '\n';
        }
      }
    }
    // emit rule iff there is cssText
    if (cssText) {
      if (node.selector) {
        text += node.selector + ' ' + OPEN_BRACE + '\n';
      }
      text += cssText;
      if (node.selector) {
        text += CLOSE_BRACE + '\n\n';
      }
    }
    return text;
  }

  var OPEN_BRACE = '{';
  var CLOSE_BRACE = '}';

  function hasMixinRules(rules) {
    return (rules[0].selector.indexOf(VAR_START) >= 0);
  }

  function removeCustomProps(cssText) {
    return cssText
      .replace(rx.customProp, '')
      .replace(rx.mixinProp, '')
      .replace(rx.mixinApply, '');
  }

  var VAR_START = '--';

  // helper regexp's
  var rx = {
    comments: /\/\*[^*]*\*+([^/*][^*]*\*+)*\//gim,
    port: /@import[^;]*;/gim,
    customProp: /--[^;{]*?:[^{};]*?;/gim,
    mixinProp: /--[^;{]*?:[^{;]*?{[^}]*?}/gim,
    mixinApply: /@mixin[\s]*\([^)]*?\)[\s]*;/gim
  };

  // exports 
  Polymer.CssParse = {
    parse: parse,
    stringify: stringify
  };

})();

</script>