Import Polymer 0.8 and several key elements.

third_party/polymer/v0_8/components-chromium/polymer/src/lib/css-parse-extracted.js

+
+
+/*
+  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
+  };
+
+})();
+