refs #5049 log to console (if exist) if methods, that are applied first, are registered multiple times. We do not throw an error as this would prevent script execution

1 files changed, 13 insertions, 3 deletions

diff --git a/js/piwik.js b/js/piwik.js
index a714d0e923..84931dbbe5 100644
--- a/js/piwik.js
+++ b/js/piwik.js
@@ -3132,13 +3132,23 @@ if (typeof Piwik !== 'object') {
 
         asyncTracker = new Tracker();
 
+        var applyFirst = {setTrackerUrl: 1, setAPIUrl: 1, setSiteId: 1};
+
         // find the call to setTrackerUrl or setSiteid (if any) and call them first
         for (iterator = 0; iterator < _paq.length; iterator++) {
-            if (_paq[iterator][0] === 'setTrackerUrl'
-                    || _paq[iterator][0] === 'setAPIUrl'
-                    || _paq[iterator][0] === 'setSiteId') {
+            var methodName = _paq[iterator][0];
+
+            if (applyFirst[methodName]) {
                 apply(_paq[iterator]);
                 delete _paq[iterator];
+
+                if (applyFirst[methodName] > 1) {
+                    if (typeof console !== 'undefined' && console && console.error) {
+                        console.error('The method ' + methodName + ' is registered more than once in "_paq" variable. Only the last call has an effect. Please have a look at the multiple Piwik trackers documentation: http://developer.piwik.org/api-reference/tracking-javascript#multiple-piwik-trackers');
+                    }
+                }
+
+                applyFirst[methodName]++;
             }
         }