Re-use div-container if already present and re-check content for dynamically loaded content

TogglLibrary.js

@@ -16,6 +16,7 @@ function TogglButtonGM(selector, renderer) {
     $newApiUrl = "https://www.toggl.com/api/v8",
     $legacyApiUrl = "https://new.toggl.com/api/v8",
     $triedAlternative = false,
+    $addedDynamicListener = false,
     $api_token = null,
     $default_wid = null,
     $clientMap = {},
@@ -119,34 +120,48 @@ function TogglButtonGM(selector, renderer) {
     if (selector == null) {
       return;
     }
-    var i, len, elems = document.querySelectorAll(selector);
+    var i, len, elems = document.querySelectorAll(selector + ':not(.toggl)');
     for (i = 0, len = elems.length; i < len; i += 1) {
       elems[i].classList.add('toggl');
       $instances[i] = new TogglButtonGMInstance(renderer(elems[i]));
     }
-    document.addEventListener('TogglButtonGMUpdateStatus', function() {
-      GM_xmlhttpRequest({
-        method: "GET",
-        url: $activeApiUrl + "/time_entries/current",
-        headers: {
-          "Authorization": "Basic " + btoa($api_token + ':api_token')
-        },
-        onload: function (result) {
-          if (result.status === 200) {
-            var resp = JSON.parse(result.responseText),
-              data = resp.data || false;
-            if (data) {
-              for (i in $instances) {
-                $instances[i].checkCurrentLinkStatus(data);
+
+    if (!$addedDynamicListener) {
+      $addedDynamicListener = true;
+
+      document.addEventListener('TogglButtonGMUpdateStatus', function() {
+        GM_xmlhttpRequest({
+          method: "GET",
+          url: $activeApiUrl + "/time_entries/current",
+          headers: {
+            "Authorization": "Basic " + btoa($api_token + ':api_token')
+          },
+          onload: function (result) {
+            if (result.status === 200) {
+              var resp = JSON.parse(result.responseText),
+                data = resp.data || false;
+              if (data) {
+                for (i in $instances) {
+                  $instances[i].checkCurrentLinkStatus(data);
+                }
               }
             }
           }
-        }
+        });
       });
-    });
-    window.addEventListener('focus', function() {
-      document.dispatchEvent(new CustomEvent('TogglButtonGMUpdateStatus'));
-    });
+
+      window.addEventListener('focus', function() {
+        document.dispatchEvent(new CustomEvent('TogglButtonGMUpdateStatus'));
+      });
+
+      if (selector !== 'body') {
+        document.body.addEventListener('DOMSubtreeModified', function () {
+          setTimeout(function () {
+            render(selector, renderer);
+          }, 1000);
+        });
+      }
+    }
   }
 
   this.clickLinks = function() {
@@ -341,13 +356,26 @@ function TogglButtonGM(selector, renderer) {
 
       document.querySelector('body').classList.add('toggl-button-available');
       if (params.targetSelectors == undefined) {
-        var wrapper = document.createElement('div'),
+        var wrapper,
+          existingWrapper = document.querySelectorAll('#toggl-button-wrapper'),
           content = createTag('div', 'content');
-        wrapper.id = 'toggl-button-wrapper';
         content.appendChild($link);
         content.appendChild(createProjectSelect());
-        wrapper.appendChild(content);
-        document.querySelector('body').appendChild(wrapper);
+        if (existingWrapper.length > 0) {
+          console.log('Re-use existing toggl');
+          wrapper = existingWrapper[0];
+          while (wrapper.firstChild) {
+            wrapper.removeChild(wrapper.firstChild);
+          }
+          wrapper.appendChild(content);
+        }
+        else {
+          console.log('Create new toggl');
+          wrapper = document.createElement('div');
+          wrapper.id = 'toggl-button-wrapper';
+          wrapper.appendChild(content);
+          document.querySelector('body').appendChild(wrapper);
+        }
       } else {
         var elem = params.targetSelectors.context || document;
         if (params.targetSelectors.link != undefined) {