Adding Content with Event Handlers

While the Navigator Control is building the menu, it raises events. This means that it will run code that you provide (called event handlers) during processing. Your code can change the appearance and content of the resulting menu. This document describes using event handlers to add static items to the menu.

Three events are raised during the processing of the menu:

Event	Description
TopLevelCreated	Raised after the top-level items have been identified and added to the list of items that will be in the menu. The subcategories have not yet been added.
SubcategoriesCreated	Raised each time a group of subcategories, all at the same level, have been identified and added to the list of items that will be in the menu.
ItemCreated	Raised each time an item is added to the menu from the list described in the other 2 events.

The best events to use for adding content are TopLevelCreated and SubcategoriesCreated. In both of these events, you have access to the list of items that will be displayed in the menu. You can add or delete items in your event handler. To add an event handler, you follow these 2 steps:

Add the code as a script block that is run at the server.
Tell the Navigator Control what code to run for the event.

Example

In this walk through, we will add an event handler to TextNavigator1.ascx that adds a link to the "Contact Us" page at ContactUs.aspx (this assumes you created this page). You can check your work by comparing it to TextNavigator5.ascx in the Controls directory of the distribution and copied to the Controls directory of your store. TextNavigator5.ascx uses a very similar technique to add 2 items to the menu.

Open Controls/TextNavigator1.ascx and paste the lines shown in red:

<%@ Control Language="vb" Inherits="System.Web.UI.UserControl" %>
<%@ Register 
    TagPrefix="sfaddons" 
    Namespace="StructuredSolutions.WebControls" 
    Assembly="SSNavigator" %>
<%' © 2005 Structured Solutions %>

<script runat="server">
   Sub TopLevelCreated(ByVal sender As Object, _
       ByVal e As StructuredSolutions.WebControls.NavigatorItemListEventArgs)
       
      Dim item As StructuredSolutions.WebControls.NavigatorItem
       
      ' Add one item to the bottom of the list
      item = New StructuredSolutions.WebControls.NavigatorItem()
      item.DisplayName = "Contact Us"
      item.Link = "ContactUs.aspx"
      e.Items.Add(item)
   End Sub
</script>

Add the parameter shown in red to the <sfaddons:Navigator> tag:

<sfaddons:Navigator id="Navigator1" runat="server" 
   OnTopLevelCreated="TopLevelCreated">

Save your changes and close the file.
Copy TextNavigator1.ascx to ssl/Controls.

Open a store page and you will see the effect of your changes. The "Contact Us" item will always appear on the menu, regardless of whether you are using Depth="Tree" or Depth="Branch".

Version 1.3.2