MAGETWO-37594: Implementation and fixes after review

Author: slopok

app/code/Magento/Catalog/view/adminhtml/web/js/new-category-dialog.js

@@ -59,11 +59,11 @@ define([
                 buttons: [{
                     text: $.mage.__('Create Category'),
                     class: 'action-primary',
-                    click: function () {
+                    click: function (e) {
                         if (!newCategoryForm.valid()) {
                             return;
                         }
-                        var thisButton = $(this);
+                        var thisButton = $(e.currentTarget);
 
                         thisButton.prop('disabled', true);
                         $.ajax({

app/code/Magento/Ui/view/base/web/js/dialog/dialog.js

@@ -176,7 +176,7 @@ define([
             _.each(this.options.buttons, function(btn, key) {
                 var button = that.buttons[key];
 
-                $(button).on('click', _.bind(btn.click, button));
+                $(button).on('click', _.bind(btn.click, that));
             });
         },
         /**