Support for observable models, fixes #259

lib/src/codegen.dart

 // Copyright (c) 2012, 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.
 
 /** Collects common snippets of generated code. */
 library codegen;
 
 import 'file_system/path.dart';
 import 'info.dart';
 import 'utils.dart';
 
 /**
  * Header with common imports, used in every generated .dart file.  If path is
  * null then there is no file associated with the template (used by testing
  * so we'll display <MEMORY> for file name.
  */
-String header(Path path, String libraryName) => """
+String header(Path path, String libraryName) {
+  var library = libraryName != null ? '\nlibrary $libraryName;\n' : '';
+  return """
 // Auto-generated from ${path != null ? path.filename : "<MEMORY>"}.
 // DO NOT EDIT.
-
-library $libraryName;
-
+$library
 $imports
 """;
+}
 
 // TODO(sigmund): include only those imports that are used by the code.
 String get imports => """
 import 'dart:html' as autogenerated;
 import 'dart:svg' as autogenerated_svg;
 import 'package:web_ui/web_ui.dart' as autogenerated;
 """;
 
 /**
  * The code that will be used to bootstrap the application, this is inlined in
  * the main.html.html output file.
  */
-String bootstrapCode(Path userMainImport) => """
+String bootstrapCode(Path userMainImport, bool useObservers) => """
 library bootstrap;
 
+import 'package:web_ui/watcher.dart' as watcher;
 import '$userMainImport' as userMain;
 
 main() {
+  watcher.useObservers = $useObservers;
   userMain.main();
   userMain.init_autogenerated();
 }
 """;
 
 /** Generate text for a list of imports. */
 String importList(Iterable<Path> imports) =>
-  imports.map((url) => "import '$url';").join('\n');
-
-/**
- * Text corresponding to a directive, fixed in case the code is in a different
- * output location.
- */
-String directiveText(
-    DartDirectiveInfo directive, LibraryInfo src, PathInfo pathInfo) {
-  var buff = new StringBuffer();
-  var uri = pathInfo.transformUrl(src.inputPath, directive.uri);
-  buff..add(directive.label)
-      ..add(" '")
-      ..add(uri.replaceAll("'", "\\'"))
-      ..add("'");
-  if (directive.prefix != null) {
-    buff..add(' as ')
-        ..add(directive.prefix);
-  }
-  if (directive.show != null) {
-    buff..add(' show ')
-        ..add(directive.show.join(','));
-  }
-  if (directive.hide != null) {
-    buff..add(' hide ')
-        ..add(directive.hide.join(','));
-  }
-  buff.add(';');
-  return buff.toString();
-}
+    imports.map((url) => "import '$url';").join('\n');