Merge pull request #333 from ably/PUB-1041/object-sync

[PUB-1041] OBJECT_SYNC spec

Author: VeskeR

src/features.md

@@ -1265,11 +1265,12 @@ as it is useful as a reference and also needs to be kept up to date*
     string it should be encoded to binary using UTF-8 before being
     passed as base argument of the `VCDiffDecoder.decode` method.
 - `(PC5)` A plugin provided with the `PluginType` enum key value of
-  `Objects` should provide the [RealtimeObjects](#RTO1) feature
-  functionality for realtime channels ([RTL27](#RTL27)). The plugin
-  object itself is not expected to provide a public API. The type of the
-  plugin object, and how it enables the Objects feature for a realtime
-  channel, are left for individual implementations to decide.
+  `Objects` should provide the
+  [RealtimeObjects](../objects-features#RTO1) feature functionality for
+  realtime channels ([RTL27](#RTL27)). The plugin object itself is not
+  expected to provide a public API. The type of the plugin object, and
+  how it enables the Objects feature for a realtime channel, are left
+  for individual implementations to decide.
 - `(PC4)` A client library is allowed to accept plugins other than those
   specified in this specification, through the use of additional
   `ClientOptions.plugins` keys defined by that library. The library is
@@ -2217,11 +2218,14 @@ makes extensive use of goroutines and channels.
 - `(RTL23)` `RealtimeChannel#name` attribute is a string containing the
   channel’s name
 - `(RTL1)` As soon as a `RealtimeChannel` becomes attached, all incoming
-  messages and presence messages (where ‘incoming’ is defined as
-  ‘received from Ably over the realtime transport’) are processed and
-  emitted where applicable. `PRESENCE` and `SYNC` messages are passed to
-  the `RealtimePresence` object ensuring it maintains a map of current
-  members on a channel in realtime
+  messages, presence messages and object messages (where ‘incoming’ is
+  defined as ‘received from Ably over the realtime transport’) are
+  processed and emitted where applicable. `PRESENCE` and `SYNC` messages
+  are passed to the `RealtimePresence` object ensuring it maintains a
+  map of current members on a channel in realtime. `OBJECT` and
+  `OBJECT_SYNC` messages are passed to the `RealtimeObjects` object
+  ensuring it maintains an up-to-date representation of objects on a
+  channel in realtime
 - `(RTL2)` The `RealtimeChannel` implements `EventEmitter` and emits
   `ChannelEvent` events, where a `ChannelEvent` is either a
   `ChannelState` or `UPDATE`, and a `ChannelState` is either
@@ -2614,7 +2618,7 @@ makes extensive use of goroutines and channels.
   - `(RTL9a)` Returns the `RealtimePresence` object for this channel
 - `(RTL27)` `RealtimeChannel#objects` attribute:
   - `(RTL27a)` Returns the `RealtimeObjects` object for this channel
-    [RTO1](#RTO1)
+    [RTO1](../objects-features#RTO1)
   - `(RTL27b)` It is a programmer error to access this property without
     first providing the `Objects` plugin ([PC5](#PC5)) in the client
     options. This programmer error should be handled in an idiomatic
@@ -3190,8 +3194,9 @@ makes extensive use of goroutines and channels.
 
 ### RealtimeObjects
 
-Reserved for `RealtimeObjects` feature specification. Reserved spec
-points: `RTO`, `RTLO`, `RTLC`, `RTLM`
+Reserved for `RealtimeObjects` feature specification, see
+[objects-features](../objects-features). Reserved spec points: `RTO`,
+`RTLO`, `RTLC`, `RTLM`
 
 ### RealtimeAnnotations