Using the SiteMapDataSource Control

Using the `SiteMapDataSource` Control

The SiteMapDataSource control enables you to represent a Site Map declaratively in a page. You can bind navigation controls such as the treeView and Menu controls to a SiteMapDataSource control. You also can bind other controls such as the GridView or DropDownList control to a SiteMapDataSource control.

Imagine, for example, that your website contains the Web.sitemap file in Listing 18.1. Because the default SiteMapProvider is the XmlSiteMapProvider, the SiteMapDataSource control automatically represents the contents of this XML file.

Note

The code samples in this section are located in the SiteMaps application on the CD that accompanies this book.

Listing 18.1. `Web.sitemap`

<?xml version="1.0" encoding="utf-8" ?> <siteMap xmlns="http://schemas.microsoft.com/AspNet/SiteMap-File-1.0" > <siteMapNode   url="Default.aspx"   title="Home"   description="The Home Page">   <siteMapNode     url="Products/Default.aspx"     title="Our Products"     description="Products that we offer">     <siteMapNode       url="Products/FirstProduct.aspx"       title="First Product"       description="The description of the First Product" />     <siteMapNode       url="Products/SecondProduct.aspx"       title="Second Product"       description="The description of the Second Product" />   </siteMapNode>   <siteMapNode     url="Services/Default.aspx"     title="Our Services"     description="Services that we offer">     <siteMapNode       url="Services/FirstService.aspx"       title="First Service"       description="The description of the First Service"       metaDescription="The first service" />     <siteMapNode       url="Services/SecondService.aspx"       title="Second Service"       description="The description of the Second Service" />   </siteMapNode> </siteMapNode> </siteMap>

The Site Map file in Listing 18.1 represents a website with the following folder and page structure:

Default.aspx Products     FirstProduct.aspx     SecondProduct.aspx Services     FirstService.aspx     SecondService.aspx

The page in Listing 18.2 illustrates how you can represent a Site Map by binding a treeView control to the SiteMapDataSource control.

Listing 18.2. `Default.aspx`

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<%@ Page Language="VB" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD /xhtml11.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head  runat="server">     <title>Home</title> </head> <body>     <form  runat="server">     <div>     <asp:SiteMapPath                  Runat="server" />     <hr />     <asp:TreeView                  DataSource         Runat="server" />     <asp:SiteMapDataSource                  Runat="server" />     </div>     </form> </body> </html>

When you open the page in Listing 18.2, all the elements from the Web.sitemap file are displayed in the treeView control with the help of the SiteMapDataSource control (see Figure 18.1).

Figure 18.1. Displaying a Site Map with a `treeView` control.

Setting `SiteMapDataSource` Properties

The SiteMapDataSource control includes several valuable properties that you can set to modify the nodes that the control returns:

ShowStartingNode Enables you to hide the starting node.
StartFromCurrentNode Enables you to return all nodes starting from the current node.
StartingNodeOffset Enables you to specify a positive or negative offset from the current node.
StartingNodeUrl Enables you to return all nodes, starting at a node associated with a specified URL.

The most useful of these properties is the ShowStartingNode property. Normally, when you display a list of nodes with a Menu or TreeView control, you do not want to display the starting node (the link to the home page). The page in Listing 18.3 illustrates how you can bind a Menu control to a SiteMapDataSource that has the value False assigned to its ShowStartingNode property.

Listing 18.3. `Services/Default.aspx`

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<%@ Page Language="VB" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/ xhtml11/DTD /xhtml11.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head  runat="server">     <style type="text/css">         .menuItem         {             border:solid 1px black;             background-color:#eeeeee;             padding:4px;             margin:1px 0px;         }     </style>     <title>Our Services</title> </head> <body>     <form  runat="server">     <div>     <asp:SiteMapPath                  Runat="server" />     <hr />     <asp:Menu                  DataSource         StaticMenuItemStyle-Css         DynamicMenuItemStyle-Css         Runat="server" />     <asp:SiteMapDataSource                  ShowStartingNode="false"         Runat="server" />     </div>     </form> </body> </html>

When you open the page in Listing 18.3, only the second-level nodes and descendent nodes are displayed (see Figure 18.2).

Figure 18.2. Hiding the starting node.

The StartFromCurrentNode property is useful when you want to display a list of all nodes below the current node. For example, the page in Listing 18.4 is the Default.aspx page contained in the Products folder. It displays a list of all the product pages contained in the folder.

Listing 18.4. `Products/Default.aspx`

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<%@ Page Language="VB" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/ xhtml11/DTD /xhtml11.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head  runat="server">     <style type="text/css">         html         {             font:16px Georgia,Serif;         }         .productList li         {             margin:5px;         }     </style>     <title>Our Products</title> </head> <body>     <form  runat="server">     <div>     <h1>Products</h1>     <asp:BulletedList                  DisplayMode="HyperLink"         DataTextField="Title"         DataValueField="Url"         DataSource         Css         Runat="server" />     <asp:SiteMapDataSource                  ShowStartingNode="false"         StartFromCurrentNode="true"         Runat="server" />     </div>     </form> </body> </html>

The page in Listing 18.4 contains a BulletedList control bound to a SiteMapDataSource control. Because the SiteMapDataSource control has its StartFromCurrentNode property set to the value TRue and its ShowStartingNode property set to the value False, all immediate child nodes of the current node are displayed (see Figure 18.3).

Figure 18.3. Displaying the contents of a folder.