Support faster deletes of sections

cms/djangoapps/contentstore/views/tests/test_course_index.py

@@ -259,7 +259,7 @@ class TestCourseOutline(CourseTestCase):
     def test_course_outline_initial_state(self):
         course_module = modulestore().get_item(self.course.location)
         course_structure = create_xblock_info(
-           course_module,
+            course_module,
             include_child_info=True,
             include_children_predicate=lambda xblock: not xblock.category == 'vertical'
         )

cms/djangoapps/contentstore/views/tests/test_item.py

@@ -1190,7 +1190,7 @@ class TestXBlockInfo(ItemTest):
                 for child_response in xblock_info['child_info']['children']:
                     self.validate_xblock_info_consistency(
                         child_response,
-                        has_child_info=(not child_response.get('child_info', None) == None)
+                        has_child_info=(not child_response.get('child_info', None) is None)
                     )
         else:
             self.assertIsNone(xblock_info.get('child_info', None))

cms/static/js/spec/views/pages/course_outline_spec.js

@@ -245,6 +245,22 @@ define(["jquery", "js/spec_helpers/create_sinon", "js/spec_helpers/view_helpers"
 
             describe("Section", function() {
                 it('can be deleted', function() {
+                    var promptSpy = view_helpers.createPromptSpy(), requestCount;
+                    createCourseOutlinePage(this, createMockCourseJSON('mock-course', 'Mock Course', [
+                        createMockSectionJSON('mock-section', 'Mock Section', []),
+                        createMockSectionJSON('mock-section-2', 'Mock Section 2', [])
+                    ]));
+                    outlinePage.$('.outline-item-section .delete-button').first().click();
+                    view_helpers.confirmPrompt(promptSpy);
+                    requestCount = requests.length;
+                    create_sinon.expectJsonRequest(requests, 'DELETE', '/xblock/mock-section');
+                    create_sinon.respondWithJson(requests, {});
+                    expect(requests.length).toBe(requestCount); // No fetch should be performed
+                    expect(outlinePage.$('[data-locator="mock-section"]')).not.toExist();
+                    expect(outlinePage.$('[data-locator="mock-section-2"]')).toExist();
+                });
+
+                it('can be deleted if it is the only section', function() {
                     var promptSpy = view_helpers.createPromptSpy();
                     createCourseOutlinePage(this, mockSingleSectionCourseJSON);
                     outlinePage.$('.outline-item-section .delete-button').click();

cms/static/js/views/course_outline.js

@@ -117,6 +117,19 @@ define(["jquery", "underscore", "js/views/xblock_outline", "js/views/utils/view_
                 }
             },
 
+            onChildDeleted: function(childView) {
+                var xblockInfo = this.model,
+                    childCategory = childView.model.get('category'),
+                    children = xblockInfo.get('child_info') && xblockInfo.get('child_info').children;
+                // If deleting a section that isn't the final one, just remove it for efficiency
+                // as it cannot visually effect the other sections.
+                if (childCategory === 'chapter' && children && children.length > 1) {
+                    childView.$el.remove();
+                } else {
+                    this.refresh();
+                }
+            },
+
             createNewItemViewState: function(locator, scrollOffset) {
                 return {
                     locator_to_show: locator,

cms/static/js/views/xblock_outline.js

@@ -135,10 +135,7 @@ define(["jquery", "underscore", "gettext", "js/views/baseview", "js/views/utils/
              */
             addButtonActions: function(element) {
                 var self = this;
-                element.find('.delete-button').click(function(event) {
-                    event.preventDefault();
-                    self.deleteXBlock($(event.target));
-                });
+                element.find('.delete-button').click(_.bind(this.handleDeleteEvent, this));
                 element.find('.add-button').click(_.bind(this.handleAddEvent, this));
             },
 
@@ -203,6 +200,14 @@ define(["jquery", "underscore", "gettext", "js/views/baseview", "js/views/utils/
                 this.initialState = null;
             },
 
+            /**
+             * Refresh the view's model from the server, which will cause the view to refresh.
+             * @returns {jQuery promise} A promise representing the refresh operation.
+             */
+            refresh: function() {
+                return this.model.fetch();
+            },
+
             onChildAdded: function(locator, category) {
                 // For units, redirect to the new page, and for everything else just refresh inline.
                 if (category === 'vertical') {
@@ -220,23 +225,17 @@ define(["jquery", "underscore", "gettext", "js/views/baseview", "js/views/utils/
                 this.refresh();
             },
 
-            deleteXBlock: function() {
-                var parentView = this.parentView;
+            handleDeleteEvent: function(event) {
+                var self = this,
+                    parentView = this.parentView;
+                event.preventDefault();
                 XBlockViewUtils.deleteXBlock(this.model).done(function() {
                     if (parentView) {
-                        parentView.onChildDeleted();
+                        parentView.onChildDeleted(self, event);
                     }
                 });
             },
 
-            /**
-             * Refresh the view's model from the server, which will cause the view to refresh.
-             * @returns {jQuery promise} A promise representing the refresh operation.
-             */
-            refresh: function() {
-                return this.model.fetch();
-            },
-
             handleAddEvent: function(event) {
                 var self = this,
                     target = $(event.target),