From 2960d4cdc26e9d09aac0bf6de89138010b8921e6 Mon Sep 17 00:00:00 2001
From: Victor Woeltjen <victor.woeltjen@nasa.gov>
Date: Thu, 15 Jan 2015 19:07:49 -0800
Subject: [PATCH] [Fixed Position] All subscription callback to be undefined

Allow callback provided when subscribing to telemetry using
telemetrySubscriber to be omitted; this permits usage of
the resulting subscription more directly from controllers,
such as for fixed position view, WTD-615.
---
 platform/telemetry/src/TelemetrySubscription.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/platform/telemetry/src/TelemetrySubscription.js b/platform/telemetry/src/TelemetrySubscription.js
index 5e929d8ee4..c8d3914726 100644
--- a/platform/telemetry/src/TelemetrySubscription.js
+++ b/platform/telemetry/src/TelemetrySubscription.js
@@ -58,7 +58,10 @@ define(
             // Invoke the observer callback to notify that new streaming
             // data has become available.
             function fireCallback() {
-                callback();
+                // Fire callback, if one was provided
+                if (callback) {
+                    callback();
+                }
                 // Clear the pending flag so that future updates will
                 // schedule this callback.
                 updatePending = false;