Allow subscribe to return events from a subject even when not creating a subscription

api.py

@@ -114,16 +114,17 @@ def SendMessage(google_user, client, instance_id, args):
 
 def Subscribe(google_user, client, instance_id, args):
   instance = models.Instance.FromID(instance_id)
+  subject = models.Subject.FindOrCreate(args['subject'])
+  messages = args.get('messages', 0)
+  last_id = args.get('last_id', None)
+
   if not instance or not instance.active:
     # Probably a race with the channel opening
     return {
       'result': 'retry',
+      'events': subject.GetEvents(messages, last_id),
     }
 
-  subject = models.Subject.FindOrCreate(args['subject'])
-  messages = args.get('messages', 0)
-  last_id = args.get('last_id', None)
-
   try:
     return {
       'result': 'ok',

lib/models.py

@@ -297,6 +297,15 @@ class Subject(db.Model):
       ret['writable_only_by'] = str(writable_only_by)
     return ret
 
+  @db.transactional()
+  def GetEvents(self, messages, last_id):
+    events = [m.ToEvent() for m in self.GetPins()]
+    if messages:
+      events.extend(m.ToEvent() for m in self.GetRecentMessages(messages))
+    if last_id is not None:
+      events.extend(m.ToEvent() for m in self.GetMessagesSince(last_id))
+    return events
+
 
 class Subscription(db.Model):
   # parent=Subject
@@ -319,12 +328,7 @@ class Subscription(db.Model):
         .fetch(1))
     if not subscriptions:
       cls(parent=subject, instance=instance).put()
-    events = [m.ToEvent() for m in subject.GetPins()]
-    if messages:
-      events.extend(m.ToEvent() for m in subject.GetRecentMessages(messages))
-    if last_id is not None:
-      events.extend(m.ToEvent() for m in subject.GetMessagesSince(last_id))
-    return events
+    return subject.GetEvents(messages, last_id)
 
   @classmethod
   @db.transactional()

static/test.js

@@ -117,6 +117,28 @@ asyncTest('Message round trip', function() {
   cosmo.subscribe(subject, -1);
 });
 
+asyncTest('Message round trip without channel', function() {
+  expect(2);
+
+  var subject = randstring();
+  var message = randstring();
+
+  var callbacks = {
+    'onMessage': function(e) {
+      equal(e['subject']['name'], subject, 'subject matches');
+      equal(e['message'], message, 'message matches');
+      cosmo.shutdown();
+      start();
+    }
+  };
+
+  var cosmo = new Cosmopolite(callbacks, null, randstring());
+  cosmo.channelState_ = Cosmopolite.ChannelState_.OPENING;
+  cosmo.sendMessage(subject, message);
+  cosmo.subscribe(subject, -1);
+});
+
+
 asyncTest('Complex object', function() {
   expect(2);