Alert in navigation bar if there is a new error in logs

docs-web/src/main/webapp/app/docs/controller/Navigation.js

@@ -5,7 +5,42 @@
  */
 App.controller('Navigation', function($scope, $http, $state, $rootScope, User, Restangular) {
   $rootScope.userInfo = User.userInfo();
-  
+
+  // Last time when the errors logs was checked
+  $scope.lastLogCheck = new Date().getTime();
+
+  // Number of errors logs
+  $scope.errorNumber = 0;
+
+  // Check repeatedly if there is a new error log
+  setInterval(function() {
+    $scope.$apply(function() {
+      Restangular.one('app/log').get({
+        limit: 100,
+        level: 'ERROR'
+      }).then(function(data) {
+          // Add new errors
+          $scope.errorNumber += _.reduce(data.logs, function(number, log) {
+            if (log.date > $scope.lastLogCheck) {
+              return ++number; // It's a new error
+            }
+            return number; // Not a new error
+          }, 0);
+
+          // Update last check timestamp
+          $scope.lastLogCheck = new Date().getTime();
+        });
+    })
+  }, 10000);
+
+  /**
+   * Navigate to error logs.
+   */
+  $scope.openLogs = function() {
+    $scope.errorNumber = 0;
+    $state.transitionTo('settings.log');
+  };
+
   /**
    * User logout.
    */
@@ -16,7 +51,10 @@ App.controller('Navigation', function($scope, $http, $state, $rootScope, User, R
     });
     $event.preventDefault();
   };
-  
+
+  /**
+   * Returns true if at least an asynchronous request is in progress.
+   */
   $scope.isLoading = function() {
     return $http.pendingRequests.length > 0;
   };