Remove platform.js from polymer.html, hint in the linter that it should be used

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

Index: pkg/polymer/lib/src/build/linter.dart
diff --git a/pkg/polymer/lib/src/build/linter.dart b/pkg/polymer/lib/src/build/linter.dart
index f0a231b2503bbe4c648112d939ca89cd1b67dcad..20b50b7b4ebb26f9d6fc3a95e01d45ceea403b56 100644
--- a/pkg/polymer/lib/src/build/linter.dart
+++ b/pkg/polymer/lib/src/build/linter.dart
@@ -37,7 +37,7 @@ class Linter extends Transformer with PolymerTransformer {
     return readPrimaryAsHtml(transform).then((document) {
       return _collectElements(document, id, transform, seen).then((elements) {
         bool isEntrypoint = options.isHtmlEntryPoint(id);
-        new _LinterVisitor(transform.logger, elements, isEntrypoint)
+        new _LinterVisitor(id, transform.logger, elements, isEntrypoint)
             .run(document);
       });
     });
@@ -55,7 +55,15 @@ class Linter extends Transformer with PolymerTransformer {
         // Note: the import order is relevant, so we visit in that order.
         .then((ids) => Future.forEach(ids,
               (id) => _readAndCollectElements(id, transform, seen, elements)))
-        .then((_) => _addElements(document, transform.logger, elements))
+        .then((_) {
+          if (sourceId.package == 'polymer' &&
+              sourceId.path == 'lib/src/js/polymer/polymer.html' &&
+              elements['polymer-element'] == null) {
+            elements['polymer-element'] =
+                new _ElementSummary('polymer-element', null, null);
+          }
+          return _addElements(document, transform.logger, elements);
+        })
         .then((_) => elements);
   }
 
@@ -137,6 +145,7 @@ class _ElementSummary {
 
 class _LinterVisitor extends TreeVisitor {
   TransformLogger _logger;
+  AssetId _sourceId;
   bool _inPolymerElement = false;
   bool _dartTagSeen = false;
   bool _polymerHtmlSeen = false;
@@ -144,7 +153,8 @@ class _LinterVisitor extends TreeVisitor {
   bool _isEntrypoint;
   Map<String, _ElementSummary> _elements;
 
-  _LinterVisitor(this._logger, this._elements, this._isEntrypoint) {
+  _LinterVisitor(
+      this._sourceId, this._logger, this._elements, this._isEntrypoint) {
     // We normalize the map, so each element has a direct reference to any
     // element it extends from.
     for (var tag in _elements.values) {
@@ -170,10 +180,6 @@ class _LinterVisitor extends TreeVisitor {
   void run(Document doc) {
     visit(doc);
 
-    if (_isEntrypoint && !_polymerHtmlSeen && !_polymerExperimentalHtmlSeen) {
-      _logger.warning(USE_POLYMER_HTML, span: doc.body.sourceSpan);
-    }
-
     if (_isEntrypoint && !_dartTagSeen && !_polymerExperimentalHtmlSeen) {
       _logger.warning(USE_INIT_DART, span: doc.body.sourceSpan);
     }
@@ -195,9 +201,14 @@ class _LinterVisitor extends TreeVisitor {
       return;
     }
 
-    if (href == 'packages/polymer/polymer.html') {
-      _polymerHtmlSeen = true;
-    } else if (href == POLYMER_EXPERIMENTAL_HTML) {
+    if (rel != 'import') return;
+
+    if (_inPolymerElement) {
+      _logger.error(NO_IMPORT_WITHIN_ELEMENT, span: node.sourceSpan);

[Siggi Cherem (dart-lang), 2014/06/13 20:08:37]

this is unrelated to the rest of the changes, but should at least warn about
https://code.google.com/p/dart/issues/detail?id=18340

+      return;
+    }
+
+    if (href == POLYMER_EXPERIMENTAL_HTML) {
       _polymerExperimentalHtmlSeen = true;
     }
     // TODO(sigmund): warn also if href can't be resolved.
@@ -212,6 +223,11 @@ class _LinterVisitor extends TreeVisitor {
   /// Produce warnings if using `<polymer-element>` in the wrong place or if the
   /// definition is not complete.
   void _validatePolymerElement(Element node) {
+    if (!_elements.containsKey('polymer-element')) {
+      _logger.warning(usePolymerHtmlMessageFrom(_sourceId),
+          span: node.sourceSpan);
+    }
+
     if (_inPolymerElement) {
       _logger.error('Nested polymer element definitions are not allowed.',
           span: node.sourceSpan);
@@ -401,11 +417,29 @@ class _LinterVisitor extends TreeVisitor {
 const String ONLY_ONE_TAG =
     'Only one "application/dart" script tag per document is allowed.';
 
-const String USE_POLYMER_HTML =
-    'Besides the initPolymer invocation, to run a polymer application you need '
-    'to include the following HTML import: '
-    '<link rel="import" href="packages/polymer/polymer.html">. This will '
-    'include the common polymer logic needed to boostrap your application.';
+String usePolymerHtmlMessageFrom(AssetId id) {
+  var segments = id.path.split('/');
+  var upDirCount = 0;
+  if (segments[0] == 'lib') {
+    // lib/foo.html => ../../packages/
+    upDirCount = segments.length;
+  } else if (segments.length > 2) {
+    // web/a/foo.html => ../packages/
+    upDirCount = segments.length - 2;
+  }
+  return usePolymerHtmlMessage(upDirCount);
+}
+
+String usePolymerHtmlMessage(int upDirCount) {
+  var reachOutPrefix = '../' * upDirCount;
+  return 'Missing definition for <polymer-element>, please add the following '
+    'HTML import at the top of this file: <link rel="import" '
+    'href="${reachOutPrefix}packages/polymer/polymer.html">.';
+}
+
+const String NO_IMPORT_WITHIN_ELEMENT = 'HTML imports are not supported '

[Jennifer Messerly, 2014/06/13 21:07:47]

maybe improve the wording so it's clearly an issue with our Polymer.dart deploy
tool?

The web components folks get grumpy if we appear to be saying something in the
standard is not supported. :)

[Siggi Cherem (dart-lang), 2014/06/13 22:15:28]

Done.

+    'within polymer element definitions, yet. Please move the import out of '
+    'this <polymer-element>.';
 
 const String USE_INIT_DART =
     'To run a polymer application, you need to call "initPolymer". You can '