Extend the model of built-in widgets 
Overview
You can extend widget models to modify widgets implementation.
The following example demonstrates how to extend the model of the Navigation widget and thus modify the widget's display settings. You first implement a custom model that represents page nodes with descriptions and then modify the widget's view to use the new model.
Implement the custom model
First, in the Mvc/Models/Navigation folder you create a new view model that represents a page node. The model inherits from the default model, so it is usable. Add an extra Description property to the model:
As a result, the new model extracts page descriptions.
Next, you create a new model that is aware of the custom view model. The new navigation model inherits from the default model and exposes the same constructors. You then override the InstantiateNodeViewModel method and its overloads in the new model:
Modify the view to use the new view model
You use the NavigationView.Tabs view as a starting point. Wherever page nodes are enumerated, make sure to specify the new view model class and print the node's Description:
Rebind the model to the new implementation
You finally replace the original implementation of the Navigation widget model with the new model. You do this using Bootstrapper.Bootstrapped event. Place the following code in your Global.asax file:
List of built-in widget models
    
    
        
            | Interface | 
            Implementation | 
        
        
            IBlogModel | 
            BlogModel | 
        
        
            IBlogPostModel | 
            BlogPostModel | 
        
        
            ICardModel | 
            CardModel | 
        
        
            ICommentsModel | 
            CommentsModel | 
        
        
            IContentBlockModel | 
            ContentBlockModel | 
        
        
            IDynamicContentModel | 
            DynamicContentModel | 
        
        
            ISubscribeFormModel | 
            SubscribeFormModel  | 
        
        
            IUnsubscribeFormModel | 
            UnsubscribeFormModel | 
        
        
            IEventModel | 
            EventModel | 
        
        
            IEventSchedulerModel | 
            EventSchedulerModel | 
        
        
            IFormModel:
            
                ICaptchaModel 
                 ICheckboxesFieldModel 
                IDropdownListFieldModel 
                IFileFieldModel 
                IHiddenFieldModel 
                IMultipleChoiceFieldModel 
                INavigationFieldModel 
                IPageBreakModel 
                IParagraphTextFieldModel 
                ISectionHeaderModel 
                ISubmitButtonModel 
                ITextFieldModel 
                IFormFieldModel 
             
             | 
            
            FormModel:
            
                CaptchaModel 
                CheckboxesFieldModel 
                DropdownListFieldModel 
                FileFieldModel 
                HiddenFieldModel 
                MultipleChoiceFieldModel 
                NavigationFieldModel 
                PageBreakModel 
                ParagraphTextFieldModel 
                SectionHeaderModel 
                SubmitButtonModel 
                TextFieldModel 
                FormFieldModel 
             
             | 
        
        
            IAccountActivationModel | 
            AccountActivationModel | 
        
        
            IChangePasswordModel | 
            ChangePasswordModel | 
        
        
            ILoginFormModel | 
            LoginFormModel | 
        
        
            ILoginStatusModel | 
            LoginStatusModel | 
        
        
            IProfileModel | 
            ProfileModel | 
        
        
            IRegistrationModel | 
            RegistrationModel | 
        
        
            IUsersListModel | 
            UsersListModel | 
        
        
            IEmbedCodeModel | 
            UsersListModel | 
        
        
            IJavaScriptModel | 
            JavaScriptModel | 
        
        
            IStyleSheetModel | 
            StyleSheetModel | 
        
        
            IListsModel | 
            ListsModel | 
        
        
            IDocumentModel | 
            DocumentModel | 
        
        
            IDocumentsListModel | 
            DocumentsListModel | 
        
        
            IImageModel | 
            ImageModel | 
        
        
            IImageGalleryModel | 
            ImageGalleryModel | 
        
        
            IVideoModel | 
            VideoModel | 
        
        
            IVideoGalleryModel | 
            VideoGalleryModel | 
        
        
            INavigationModel | 
            NavigationModel | 
        
        
            INewsModel | 
            NewsModel | 
        
        
            IFeedModel | 
            FeedModel | 
        
        
            ISearchBoxModel | 
            SearchBoxModel | 
        
        
            ISocialShareModel | 
            SocialShareModel | 
        
        
            IFlatTaxonomyModel | 
            FlatTaxonomyModel | 
        
        
            IHierarchicalTaxonomyModel | 
            HierarchicalTaxonomyModel |