Merge 73e8943 into 9201695

plugins/websocket_server/WebsocketServer.cc

@@ -262,6 +262,7 @@ int rootCallback(struct lws *_wsi,
       igndbg << "LWS_CALLBACK_HTTP\n";
       return httpCallback(_wsi, _reason, _user, _in, _len);
       break;
+
     // Publish outboud messages
     case LWS_CALLBACK_SERVER_WRITEABLE:
       {
@@ -858,7 +859,32 @@ void WebsocketServer::OnMessage(int _socketId, const std::string &_msg)
     this->node.Subscribe(frameParts[1],
         &WebsocketServer::OnWebsocketSubscribedImageMessage, this);
   }
+  else if (frameParts[0] == "unsub")
+  {
+    igndbg << "Unsubscribe request for topic[" << frameParts[1] << "]\n";
+    std::map<std::string, std::set<int>>::iterator topicConnectionIter =
+      this->topicConnections.find(frameParts[1]);
 
+    if (topicConnectionIter != this->topicConnections.end())
+    {
+      // Remove from the topic connections map
+      topicConnectionIter->second.erase(_socketId);
+
+      // Only unsubscribe from the Ignition Transport topic if there are no
+      // more websocket connections.
+      if (topicConnectionIter->second.empty())
+      {
+        igndbg << "Unsubscribing from Ignition Transport Topic["
+          << frameParts[1] << "]\n";
+        this->node.Unsubscribe(frameParts[1]);
+      }
+    }
+    else
+    {
+      ignwarn << "The websocket server is not subscribed to topic["
+        << frameParts[1] << "]. Unable to unsubscribe from the topic\n";
+    }
+  }
 }
 
 //////////////////////////////////////////////////

plugins/websocket_server/WebsocketServer.hh

@@ -91,10 +91,12 @@ namespace ignition
     ///     5. "protos": Get a string containing all the protobuf
     ///                  definitions, and
     ///     6. "particle_emitters": Get the list of particle emitters.
+    ///                  definitions.
+    ///     7. "unsub": Unsubscribe from the topic in the `topic_name` component
     ///
-    /// The `topic_name` component is mandatory for the "sub" and "pub"
-    /// operations. If present, it must be the name of an Ignition Transport
-    /// topic.
+    /// The `topic_name` component is mandatory for the "sub", "pub", and
+    /// "unsub" operations. If present, it must be the name of an Ignition
+    /// Transport topic.
     ///
     /// The `message_type` component is mandatory for the "pub" operation. If
     /// present it names the Ignition Message type, such as