Update swarm to run from the Dart Editor with demo data

samples/swarm/DataSource.dart

 // Copyright (c) 2011, 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.
 
 /** The top-level collection of all sections for a user. */
 // TODO(jimhug): This is known as UserData in the server model.
 class Sections implements Collection<Section> {
   final List<Section> _sections;
 
   Sections(this._sections);
@@ skipping 13 matching lines @@
    * Find the Section object that has a given title.
    * This is used to integrate well with [ConveyorView].
    */
   Section findSection(String name) {
     return CollectionUtils.find(_sections, (sect) => sect.title == name);
   }
 
   // TODO(jimhug): Track down callers!
   Iterator<Section> iterator() => _sections.iterator();
 
-  // TODO(jimhug): Better support for switching between local dev and server.
-  static bool get runningFromFile() {
-    return window.location.protocol.startsWith('file:');
-  }
-
   static String get home() {
     // TODO(jmesserly): window.location.origin not available on Safari 4.
     // Move this workaround to the DOM code. See bug 5389503.
     return '${window.location.protocol}//${window.location.host}';
   }
 
   // This method is exposed for tests.
   static void initializeFromData(String data, void callback(Sections sects)) {
     final decoder = new Decoder(data);
     int nSections = decoder.readInt();
     final sections = new List<Section>();
 
     for (int i=0; i < nSections; i++) {
       sections.add(Section.decode(decoder));
     }
     callback(new Sections(sections));
   }
 
-  static void initializeFromUrl(void callback(Sections sections)) {
-    if (Sections.runningFromFile) {
-      initializeFromData(CannedData.data['user.data'], callback);
-    } else {
-      // TODO(jmesserly): display an error if we fail here! Silent failure bad.
-      new XMLHttpRequest.get('data/user.data',
-          EventBatch.wrap((request) {
-        // TODO(jimhug): Nice response if get error back from server.
-        // TODO(jimhug): Might be more efficient to parse request in sections.
-        initializeFromData(request.responseText, callback);
-      }));
-    }
+  static void initializeFromUrl(void callback(Sections sections)) {   
+    // TODO(jmesserly): display an error if we fail here! Silent failure bad.
+    new XMLHttpRequest.get('data/user.data',
+        EventBatch.wrap((request) {
+          // TODO(jimhug): Nice response if get error back from server.
+          // TODO(jimhug): Might be more efficient to parse request in sections.
+          initializeFromData(request.responseText, callback);
+        }));
   }
 
   Section findSectionById(String id) {
     return CollectionUtils.find(_sections, (section) => section.id == id);
   }
 
   /**
    * Given the name of a section, find its index in the set.
    */
   int findSectionIndex(String name) {
@@ skipping 116 matching lines @@
   }
 
   String get dataUri() {
     return Uri.encodeComponent(id).replaceAll('%2F', '/').
         replaceAll('%253A', '%3A');
   }
 
   String get thumbUrl() {
     if (!hasThumbnail) return null;
 
-    var home;
-    if (Sections.runningFromFile) {
-      home = 'http://dart.googleplex.com';
-    } else {
-      home = Sections.home;
-    }
+    var home = Sections.home;
     // By default images from the real server are cached.
     // Bump the version flag if you change the thumbnail size, and you want to
     // get the new images. Our server ignores the query params but it gets
     // around appengine server side caching and the client side cache.
     return 'data/$dataUri.jpg';
   }
 
   // TODO(jimhug): need to return a lazy Observable<String> and also
   //   add support for preloading.
   void _ensureLoaded() {
     if (_htmlBody !== null) return;
 
     var name = '$dataUri.html';
-    if (Sections.runningFromFile) {
-      _htmlBody = CannedData.data[name];
-    } else {
-      // TODO(jimhug): Remove this truly evil synchronoush xhr.
-      final req = new XMLHttpRequest();
-      req.open('GET', 'data/$name', false);
-      req.send();
-      _htmlBody = req.responseText;
-    }
+    // TODO(jimhug): Remove this truly evil synchronous xhr.
+    final req = new XMLHttpRequest();
+    req.open('GET', 'data/$name', false);
+    req.send();
+    _htmlBody = req.responseText;
   }
 
   static Article decodeHeader(Feed source, Decoder decoder) {
     final id = decoder.readString();
     final title = decoder.readString();
     final srcUrl = decoder.readString();
     final hasThumbnail = decoder.readBool();
     final author = decoder.readString();
     final dateInSeconds = decoder.readInt();
     final snippet = decoder.readString();
     final date =
         new Date.fromMillisecondsSinceEpoch(dateInSeconds*1000, isUtc: true);
     return new Article(source, id, date, title, author, srcUrl, hasThumbnail,
         snippet);
   }
 }