introduce web_components pkg for consolidated polyfills

pkg/html_import/lib/src/Parser.js

-/*
- * Copyright 2013 The Polymer Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style
- * license that can be found in the LICENSE file.
- */
-
-(function(scope) {
-
-var IMPORT_LINK_TYPE = 'import';
-
-// highlander object for parsing a document tree
-
-var importParser = {
-  selectors: [
-    'link[rel=' + IMPORT_LINK_TYPE + ']',
-    'link[rel=stylesheet]',
-    'style',
-    'script:not([type])',
-    'script[type="text/javascript"]'
-  ],
-  map: {
-    link: 'parseLink',
-    script: 'parseScript',
-    style: 'parseGeneric'
-  },
-  parse: function(inDocument) {
-    if (!inDocument.__importParsed) {
-      // only parse once
-      inDocument.__importParsed = true;
-      // all parsable elements in inDocument (depth-first pre-order traversal)
-      var elts = inDocument.querySelectorAll(importParser.selectors);
-      // for each parsable node type, call the mapped parsing method
-      forEach(elts, function(e) {
-        importParser[importParser.map[e.localName]](e);
-      });
-    }
-  },
-  parseLink: function(linkElt) {
-    if (isDocumentLink(linkElt)) {
-      if (linkElt.content) {
-        importParser.parse(linkElt.content);
-      }
-    } else {
-      this.parseGeneric(linkElt);
-    }
-  },
-  parseGeneric: function(elt) {
-    if (needsMainDocumentContext(elt)) {
-      document.head.appendChild(elt);
-    }
-  },
-  parseScript: function(scriptElt) {
-    if (needsMainDocumentContext(scriptElt)) {
-      // acquire code to execute
-      var code = (scriptElt.__resource || scriptElt.textContent).trim();
-      if (code) {
-        // calculate source map hint
-        var moniker = scriptElt.__nodeUrl;
-        if (!moniker) {
-          var moniker = scope.path.documentUrlFromNode(scriptElt);
-          // there could be more than one script this url
-          var tag = '[' + Math.floor((Math.random()+1)*1000) + ']';
-          // TODO(sjmiles): Polymer hack, should be pluggable if we need to allow 
-          // this sort of thing
-          var matches = code.match(/Polymer\(['"]([^'"]*)/);
-          tag = matches && matches[1] || tag;
-          // tag the moniker
-          moniker += '/' + tag + '.js';
-        }
-        // source map hint
-        code += "\n//# sourceURL=" + moniker + "\n";
-        // evaluate the code
-        eval.call(window, code);
-      }
-    }
-  }
-};
-
-var forEach = Array.prototype.forEach.call.bind(Array.prototype.forEach);
-
-function isDocumentLink(elt) {
-  return elt.localName === 'link'
-      && elt.getAttribute('rel') === IMPORT_LINK_TYPE;
-}
-
-function needsMainDocumentContext(node) {
-  // nodes can be moved to the main document:
-  // if they are in a tree but not in the main document and not children of <element>
-  return node.parentNode && !inMainDocument(node) 
-      && !isElementElementChild(node);
-}
-
-function inMainDocument(elt) {
-  return elt.ownerDocument === document ||
-    // TODO(sjmiles): ShadowDOMPolyfill intrusion
-    elt.ownerDocument.impl === document;
-}
-
-function isElementElementChild(elt) {
-  return elt.parentNode && elt.parentNode.localName === 'element';
-}
-
-// exports
-
-scope.parser = importParser;
-
-})(HTMLImports);