(feat) added new sg-placeholder directive for dynamic placeholders

UI/WebServerResources/js/Common/sgPlaceholder.directive.js

@@ -0,0 +1,32 @@
+/* -*- Mode: javascript; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+
+(function() {
+  'use strict';
+
+  /**
+   * sgPlaceholder - A directive for dynamic placeholder
+   * @memberof SOGo.Common
+   * @ngInject
+   * @example:
+
+     <input type="text"
+            sg-placeholder="this_is_a_variable" />
+  */
+  function sgPlaceholder() {
+    return {
+      restrict: 'A',
+      scope: {
+        placeholder: '=sgPlaceholder'
+      },
+      link: function(scope, elem, attr) {
+        scope.$watch('placeholder',function() {
+          elem[0].placeholder = scope.placeholder;
+        });
+      }
+    };
+  }
+  
+  angular
+    .module('SOGo.Common')
+    .directive('sgPlaceholder', sgPlaceholder);
+})();