The PortalSiteMapProvider object provides the site hierarchy (navigation structure) and monitors the relationship between nodes.Many named instances of this site map provider are listed in the web.config file, and are also available through static properties on this class that the master pages in Office SharePoint Server 2007 deliver. Office SharePoint Server 2007 uses these named instances to provide data to the horizontal and vertical navigation menus. The application shares named instances across all Web requests on the current application domain. The class stores no session information. If necessary, session information is stored on the HttpContext class.
The PortalSiteMapDataSource object maps navigation features from the PortalSiteMapProvider and filters navigation elements to determine which are viewable to the user in the horizontal or vertical menus or in breadcrumbs.It also provides type-based trimming of navigation nodes and an extensible trimming mechanism.
Let us see the Horizontal and Vertical menus in detail in next posts…