From 1b97996ef8907726f12d3752faa4434df156d9ac Mon Sep 17 00:00:00 2001
From: ansuz <ansuz@transitiontech.ca>
Date: Thu, 7 Sep 2017 12:26:05 +0200
Subject: [PATCH] implement util.once

---
 www/common/common-util.js | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/www/common/common-util.js b/www/common/common-util.js
index 8cbde420c..e42a0249c 100644
--- a/www/common/common-util.js
+++ b/www/common/common-util.js
@@ -170,5 +170,15 @@ define([], function () {
         return parts[0];
     };
 
+    /* for wrapping async functions such that they can only be called once */
+    Util.once = function (f) {
+        var called;
+        return function () {
+            if (called) { return; }
+            called = true;
+            f.apply(this, Array.prototype.slice.call(arguments));
+        };
+    };
+
     return Util;
 });