fix imports link rel=stylesheet

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

Index: pkg/polymer/lib/src/build/common.dart
diff --git a/pkg/polymer/lib/src/build/common.dart b/pkg/polymer/lib/src/build/common.dart
index 7e62cc7adb575dde51b6aa40ddb53e58cb898176..8922e94f83e389c86ece758aac7c89036e6c285e 100644
--- a/pkg/polymer/lib/src/build/common.dart
+++ b/pkg/polymer/lib/src/build/common.dart
@@ -112,6 +112,14 @@ abstract class PolymerTransformer {
     });
   }
 
+  Future<String> readAsString(AssetId id, Transform transform) {

[Siggi Cherem (dart-lang), 2014/02/13 00:08:18]

is this method needed? seems that the first few values are not used, so this is
just doing the same as:
  transform.readInputAsString(id)

[Jennifer Messerly, 2014/02/13 06:11:22]

good catch. Out of curiosity, what is the  `var url = samePackage ? id.path ...`
business for? Should I be using it when I construct a source span -- since it
seems to be passed to the _parseHtml function?

It seems like a lot of complexity compared to just doing an id.path, just to
improve the error message... Does id.path not point at the correct path for a
user to understand a warning?

anyway I moved the URL computation into the place where I'm building the source
spans, so it matches the HTML code path as closely as possible.

[Siggi Cherem (dart-lang), 2014/02/13 17:46:33]

It's basically for better error messages.
Exactly. 
Well, only if you are in the same package. 'id.path' is a relative path from a
package's home dir, so if you have 'lib/foo/bar.dart' in 2 packages, their
id.path is the same.

The basic principle I followed was:
 - if it's on the same package, then use the path (id.path), the user will know
that a path means a file in their own code
 - if it's on another package, then use [assetUrlFor], this will likely be a
"package:" url to the file in the other package, which is enough for users to
identify where the error is.

Unfortunately, [assetUrlFor] doesn't work for the same package because we have
files in 'web' and other folders that don't have a "package:" url. [assetUrlFor]
will produce a relative URL instead.
Cool

[Jennifer Messerly, 2014/02/13 20:43:45]

Lovely explanation! Thank you :)

+    var primaryId = transform.primaryInput.id;
+    bool samePackage = id.package == primaryId.package;
+    var url = samePackage ? id.path
+        : assetUrlFor(id, primaryId, transform.logger, allowAssetUrl: true);
+    return transform.readInputAsString(id);
+  }
+
   Future<bool> assetExists(AssetId id, Transform transform) =>
       transform.getInput(id).then((_) => true).catchError((_) => false);
 
@@ -129,7 +137,8 @@ List<List<Transformer>> get phasesForPolymer =>
  * urls are not resolved unless [source] is Dart file (has a .dart extension).
  */
 // TODO(sigmund): delete once this is part of barback (dartbug.com/12610)
-AssetId resolve(AssetId source, String url, TransformLogger logger, Span span) {
+AssetId resolve(AssetId source, String url, TransformLogger logger, Span span,
+    {bool allowAbsolute: false}) {
   if (url == null || url == '') return null;
   var uri = Uri.parse(url);
   var urlBuilder = path.url;
@@ -142,7 +151,9 @@ AssetId resolve(AssetId source, String url, TransformLogger logger, Span span) {
       }
     }
 
-    logger.error('absolute paths not allowed: "$url"', span: span);
+    if (!allowAbsolute) {
+      logger.error('absolute paths not allowed: "$url"', span: span);
+    }

[Siggi Cherem (dart-lang), 2014/02/13 00:08:18]

we might want to resolve more precisely paths that start with '/' but not a
different domain. For now I think this is fine, in the future I think we will
want to treat

/packages/foo/bar

similar to 

packages/foo/bar

[Jennifer Messerly, 2014/02/13 06:11:22]

yeah agree

     return null;
   }