Rearranges the polymer package now that the old compiler is gone.

pkg/polymer/lib/src/transform/common.dart

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-/** Common methods used by transfomers. */
-library polymer.src.transform.common;
-
-import 'dart:async';
-
-import 'package:barback/barback.dart';
-import 'package:html5lib/dom.dart' show Document;
-import 'package:html5lib/parser.dart' show HtmlParser;
-import 'package:path/path.dart' as path;
-import 'package:source_maps/span.dart' show Span;
-
-/**
- * Parses an HTML file [contents] and returns a DOM-like tree. Adds emitted
- * error/warning to [logger].
- */
-Document _parseHtml(String contents, String sourcePath, TransformLogger logger,
-    {bool checkDocType: true}) {
-  // TODO(jmesserly): make HTTP encoding configurable
-  var parser = new HtmlParser(contents, encoding: 'utf8', generateSpans: true,
-      sourceUrl: sourcePath);
-  var document = parser.parse();
-
-  // Note: errors aren't fatal in HTML (unless strict mode is on).
-  // So just print them as warnings.
-  for (var e in parser.errors) {
-    if (checkDocType || e.errorCode != 'expected-doctype-but-got-start-tag') {
-      logger.warning(e.message, e.span);
-    }
-  }
-  return document;
-}
-
-/** Additional options used by polymer transformers */
-class TransformOptions {
-  String currentPackage;
-  List<String> entryPoints;
-
-  TransformOptions([this.currentPackage, this.entryPoints]);
-
-  /** Whether an asset with [id] is an entry point HTML file. */
-  bool isHtmlEntryPoint(AssetId id) {
-    if (id.extension != '.html') return false;
-
-    // Note: [id.path] is a relative path from the root of a package.
-    if (!id.path.startsWith('web/') &&
-        !id.path.startsWith('test/')) return false;
-
-    if (currentPackage == null || entryPoints == null) return true;
-    return id.package == currentPackage && entryPoints.contains(id.path);
-  }
-}
-
-/** Mixin for polymer transformers. */
-abstract class PolymerTransformer {
-  TransformOptions get options;
-
-  Future<Document> readPrimaryAsHtml(Transform transform) {
-    var asset = transform.primaryInput;
-    var id = asset.id;
-    return asset.readAsString().then((content) {
-      return _parseHtml(content, id.path, transform.logger,
-        checkDocType: options.isHtmlEntryPoint(id));
-    });
-  }
-
-  Future<Document> readAsHtml(AssetId id, Transform transform) {
-    var primaryId = transform.primaryInput.id;
-    var url = (id.package == primaryId.package) ? id.path
-        : assetUrlFor(id, primaryId, transform.logger, allowAssetUrl: true);
-    return transform.readInputAsString(id).then((content) {
-      return _parseHtml(content, url, transform.logger,
-        checkDocType: options.isHtmlEntryPoint(id));
-    });
-  }
-}
-
-/** Create an [AssetId] for a [url] seen in the [source] asset. */
-// TODO(sigmund): delete once this is part of barback (dartbug.com/12610)
-AssetId resolve(AssetId source, String url, TransformLogger logger, Span span) {
-  if (url == null || url == '') return null;
-  var uri = Uri.parse(url);
-  var urlBuilder = path.url;
-  if (uri.host != '' || uri.scheme != '' || urlBuilder.isAbsolute(url)) {
-    logger.error('absolute paths not allowed: "$url"', span);
-    return null;
-  }
-
-  var package;
-  var targetPath;
-  var segments = urlBuilder.split(url);
-  if (segments[0] == 'packages') {
-    if (segments.length < 3) {
-      logger.error("incomplete packages/ path. It should have at least 3 "
-          "segments packages/name/path-from-name's-lib-dir", span);
-      return null;
-    }
-    package = segments[1];
-    targetPath = urlBuilder.join('lib',
-        urlBuilder.joinAll(segments.sublist(2)));
-  } else if (segments[0] == 'assets') {
-    if (segments.length < 3) {
-      logger.error("incomplete assets/ path. It should have at least 3 "
-          "segments assets/name/path-from-name's-asset-dir", span);
-    }
-    package = segments[1];
-    targetPath = urlBuilder.join('asset',
-        urlBuilder.joinAll(segments.sublist(2)));
-  } else {
-    package = source.package;
-    targetPath = urlBuilder.normalize(
-        urlBuilder.join(urlBuilder.dirname(source.path), url));
-  }
-  return new AssetId(package, targetPath);
-}
-
-/**
- * Generate the import url for a file described by [id], referenced by a file
- * with [sourceId].
- */
-// TODO(sigmund): this should also be in barback (dartbug.com/12610)
-String assetUrlFor(AssetId id, AssetId sourceId, TransformLogger logger,
-    {bool allowAssetUrl: false}) {
-  // use package: and asset: urls if possible
-  if (id.path.startsWith('lib/')) {
-    return 'package:${id.package}/${id.path.substring(4)}';
-  }
-
-  if (id.path.startsWith('asset/')) {
-    if (!allowAssetUrl) {
-      logger.error("asset urls not allowed. "
-          "Don't know how to refer to $id from $sourceId");
-      return null;
-    }
-    return 'asset:${id.package}/${id.path.substring(6)}';
-  }
-
-  // Use relative urls only if it's possible.
-  if (id.package != sourceId.package) {
-    logger.error("don't know how to refer to $id from $sourceId");
-    return null;
-  }
-
-  var builder = path.url;
-  return builder.relative(builder.join('/', id.path),
-      from: builder.join('/', builder.dirname(sourceId.path)));
-}