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StaticSiteMapProvider Class

Serves as a partial implementation of the abstract SiteMapProvider class and serves as a base class for the XmlSiteMapProvider class, which is the default site map provider in ASP.NET.

Namespace:  System.Web
Assembly:  System.Web (in System.Web.dll)

public abstract class StaticSiteMapProvider : SiteMapProvider

The StaticSiteMapProvider type exposes the following members.

  NameDescription
Protected methodStaticSiteMapProviderInitializes a new instance of the StaticSiteMapProvider class.
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  NameDescription
Public propertyCurrentNodeGets the SiteMapNode object that represents the currently requested page. (Inherited from SiteMapProvider.)
Public propertyDescriptionGets a brief, friendly description suitable for display in administrative tools or other user interfaces (UIs). (Inherited from ProviderBase.)
Public propertyEnableLocalizationGets or sets a Boolean value indicating whether localized values of SiteMapNode attributes are returned. (Inherited from SiteMapProvider.)
Public propertyNameGets the friendly name used to refer to the provider during configuration. (Inherited from ProviderBase.)
Public propertyParentProviderGets or sets the parent SiteMapProvider object of the current provider. (Inherited from SiteMapProvider.)
Public propertyResourceKeyGet or sets the resource key that is used for localizing SiteMapNode attributes. (Inherited from SiteMapProvider.)
Public propertyRootNodeGets the root SiteMapNode object of the site map data that the current provider represents. (Inherited from SiteMapProvider.)
Public propertyRootProviderGets the root SiteMapProvider object in the current provider hierarchy. (Inherited from SiteMapProvider.)
Public propertySecurityTrimmingEnabledGets a Boolean value indicating whether a site map provider filters site map nodes based on a user's role. (Inherited from SiteMapProvider.)
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  NameDescription
Protected methodAddNode(SiteMapNode)Adds a SiteMapNode object to the node collection that is maintained by the site map provider. (Inherited from SiteMapProvider.)
Protected methodAddNode(SiteMapNode, SiteMapNode)Adds a SiteMapNode to the collections that are maintained by the site map provider and establishes a parent/child relationship between the SiteMapNode objects. (Overrides SiteMapProvider.AddNode(SiteMapNode, SiteMapNode).)
Public methodBuildSiteMapWhen overridden in a derived class, loads the site map information from persistent storage and builds it in memory.
Protected methodClearRemoves all elements in the collections of child and parent site map nodes that the StaticSiteMapProvider tracks as part of its state.
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodFindSiteMapNode(HttpContext)Retrieves a SiteMapNode object that represents the currently requested page using the specified HttpContext object. (Inherited from SiteMapProvider.)
Public methodFindSiteMapNode(String)Retrieves a SiteMapNode object that represents the page at the specified URL. (Overrides SiteMapProvider.FindSiteMapNode(String).)
Public methodFindSiteMapNodeFromKeyRetrieves a SiteMapNode object based on a specified key. (Overrides SiteMapProvider.FindSiteMapNodeFromKey(String).)
Public methodGetChildNodesRetrieves the child site map nodes of a specific SiteMapNode object. (Overrides SiteMapProvider.GetChildNodes(SiteMapNode).)
Public methodGetCurrentNodeAndHintAncestorNodesProvides an optimized lookup method for site map providers when retrieving the node for the currently requested page and fetching the parent and ancestor site map nodes for the current page. (Inherited from SiteMapProvider.)
Public methodGetCurrentNodeAndHintNeighborhoodNodesProvides an optimized lookup method for site map providers when retrieving the node for the currently requested page and fetching the site map nodes in the proximity of the current node. (Inherited from SiteMapProvider.)
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetParentNodeRetrieves the parent site map node of a specific SiteMapNode object. (Overrides SiteMapProvider.GetParentNode(SiteMapNode).)
Public methodGetParentNodeRelativeToCurrentNodeAndHintDownFromParentProvides an optimized lookup method for site map providers when retrieving an ancestor node for the currently requested page and fetching the descendant nodes for the ancestor. (Inherited from SiteMapProvider.)
Public methodGetParentNodeRelativeToNodeAndHintDownFromParentProvides an optimized lookup method for site map providers when retrieving an ancestor node for the specified SiteMapNode object and fetching its child nodes. (Inherited from SiteMapProvider.)
Protected methodGetRootNodeCoreWhen overridden in a derived class, retrieves the root node of all the nodes that are currently managed by the current provider. (Inherited from SiteMapProvider.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodHintAncestorNodesProvides a method that site map providers can override to perform an optimized retrieval of one or more levels of parent and ancestor nodes, relative to the specified SiteMapNode object. (Inherited from SiteMapProvider.)
Public methodHintNeighborhoodNodesProvides a method that site map providers can override to perform an optimized retrieval of nodes found in the proximity of the specified node. (Inherited from SiteMapProvider.)
Public methodInitializeInitializes the SiteMapProvider implementation, including any resources that are needed to load site map data from persistent storage. (Inherited from SiteMapProvider.)
Public methodIsAccessibleToUserRetrieves a Boolean value indicating whether the specified SiteMapNode object can be viewed by the user in the specified context. (Inherited from SiteMapProvider.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Protected methodRemoveNodeRemoves the specified SiteMapNode object from all site map node collections that are tracked by the site map provider. (Overrides SiteMapProvider.RemoveNode(SiteMapNode).)
Protected methodResolveSiteMapNodeRaises the SiteMapResolve event. (Inherited from SiteMapProvider.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
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  NameDescription
Public eventSiteMapResolveOccurs when the CurrentNode property is called. (Inherited from SiteMapProvider.)
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The StaticSiteMapProvider class is a partial implementation of the abstract SiteMapProvider class and supplies two additional methods: AddNode and RemoveNode, as well as the abstract BuildSiteMap and protected Clear methods.

The StaticSiteMapProvider class supports writing a site map provider (for example, an XmlSiteMapProvider) that translates a site map that is stored in persistent storage to one that is stored in memory. The StaticSiteMapProvider class provides basic implementations for storing and retrieving SiteMapNode objects.

The SiteMapProvider and StaticSiteMapProvider classes support the concept of a site map provider hierarchy, where a site map provider can have a hierarchical relationship with other site map providers. This pattern is implemented with the RootProvider and ParentProvider properties.

The StaticSiteMapProvider class stores its SiteMapNode objects in hash tables and internally uses the SiteMapNode.Url property of the pages, represented by site map nodes, as keys. (If a site map node does not specify a URL, it is tracked using an automatically generated unique key.) As a result, you cannot have site map nodes wherein a site map node with the same URL is used more than once. For example, attempting to load the site map node illustrated in the following code example with the XmlSiteMapProvider class, which is the default ASP.NET site map provider, or any site map provider that is derived from the StaticSiteMapProvider class will not work because the AboutUs.aspx page is used more than once.

<sitemap>
  <sitemapnode title="Home" description="Home" url="default.aspx" >
    <sitemapnode title="Catalog" description="Our catalog" url="catalog.aspx"/>
    <sitemapnode title="About Us" description="All about our company" url="aboutus.aspx"/>
    <sitemapnode title="Driving Directions" description="Directions to our store" url="aboutus.aspx"/>
  </sitemapnode>
</sitemap>

If you are extending the StaticSiteMapProvider class, the three most important methods are the GetRootNodeCore, Initialize, and BuildSiteMap methods. The Clear and FindSiteMapNode methods have default implementations that are sufficient for most custom site map provider implementations.

The Initialize method is called to initialize derived site map providers, including any resources that are required to load site map data, but it does attempt to build the site map node in memory. If your derived class is using files to store site map data, any file initialization can be performed here. If the site map node uses some other type of data store, such as a relational database, initializing a connection might be performed here. Additional attributes, such as file names or connection strings that are placed on the site map provider element in the configuration are processed by the ASP.NET configuration system and passed to the Initialize method with the attributes parameter.

The BuildSiteMap method must be overridden by all classes that are derived from the StaticSiteMapProvider class and is called to load the site map node from persistent storage and convert it to an internal representation. The BuildSiteMap method is called internally in many of the default member implementations of the StaticSiteMapProvider and XmlSiteMapProvider classes. If you implement your own site map provider, ensure that site map data processing occurs once and subsequent calls to the BuildSiteMap method return immediately, if site map information has already been loaded. When you implement the BuildSiteMap method, ensure it is thread safe, as multiple concurrent page requests can result indirectly in multiple calls to load site map information. The site map infrastructure supports displaying site map information based on the user's role. Depending on the Roles property that are supported by the individual SiteMapNode objects, a different navigation structure can exist for different users. The default implementations of the site map node retrieval members of the StaticSiteMapProvider class perform security trimming automatically by calling the IsAccessibleToUser method.

The AddNode, Clear and RemoveNode methods manipulate the internal collections that are used to track site map nodes in a thread-safe manner.

Notes to Inheritors

When you inherit from the StaticSiteMapProvider class, you must override the following member: BuildSiteMap.

The following code example demonstrates how you to extend the StaticSiteMapProvider class to use Microsoft Access as a site map provider. The AccessSiteMapProvider class is a site map provider that supports only a simple, one-level-deep hierarchy. The table that the site map data is stored in has the following structure:

NODEID URL            NAME       PARENTNODEID
 ---------------------------------------------
 1      default.aspx   Default    <NULL>
 2      catalog.aspx   Catalog    1
 3      aboutus.aspx   Contact Us 1
...

The AccessSiteMapProvider class is derived from the StaticSiteMapProvider class and retrieves its information from a Microsoft Access database using basic SQL queries and the OleDbCommand and OleDbDataReader objects.


namespace Samples.AspNet.CS.Controls {

    using System;
    using System.Collections;
    using System.Collections.Specialized;
    using System.Data;
    using System.Data.OleDb;
    using System.Security.Permissions;
    using System.Web;

    /// An extremely simple AccessSiteMapProvider that only supports a
    /// site map node hierarchy 1 level deep.
    [AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
    public class AccessSiteMapProvider : StaticSiteMapProvider
    {
        private SiteMapNode rootNode =  null;
        private OleDbConnection accessConnection = null;

        // This string is case sensitive.
        private string AccessConnectionStringName = "accessSiteMapConnectionString";

        // Implement a default constructor.
        public AccessSiteMapProvider () { }

        // Some basic state to help track the initialization state of the provider.
        private bool initialized = false;
        public virtual bool IsInitialized {
            get {
                return initialized;
            }
        }
        // Return the root node of the current site map.
        public override SiteMapNode RootNode {
            get {
                SiteMapNode temp = null;
                temp = BuildSiteMap();
                return temp;
            }
        }
        protected override SiteMapNode GetRootNodeCore() {
            return RootNode;
        }
        // Initialize is used to initialize the properties and any state that the
        // AccessProvider holds, but is not used to build the site map.
        // The site map is built when the BuildSiteMap method is called.
        public override void Initialize(string name, NameValueCollection attributes) {
            if (IsInitialized)
                return;

            base.Initialize(name, attributes);

            // Create and test the connection to the Microsoft Access database.

            // Retrieve the Value of the Access connection string from the
            // attributes NameValueCollection.
            string connectionString = attributes[AccessConnectionStringName];

            if (null == connectionString || connectionString.Length == 0)
                throw new Exception ("The connection string was not found.");
            else
                accessConnection = new OleDbConnection(connectionString);

            initialized = true;
        }

        ///
        /// SiteMapProvider and StaticSiteMapProvider methods that this derived class must override.
        ///
        // Clean up any collections or other state that an instance of this may hold.
        protected override void Clear() {
            lock (this) {
                rootNode = null;
                base.Clear();
            }
        }

        // Build an in-memory representation from persistent
        // storage, and return the root node of the site map.
        public override SiteMapNode BuildSiteMap() {

            // Since the SiteMap class is static, make sure that it is
            // not modified while the site map is built.
            lock(this) {

                // If there is no initialization, this method is being
                // called out of order.
                if (! IsInitialized) {
                    throw new Exception("BuildSiteMap called incorrectly.");
                }

                // If there is no root node, then there is no site map.
                if (null == rootNode) {
                    // Start with a clean slate
                    Clear();

                    // Select the root node of the site map from Microsoft Access.
                    int rootNodeId = -1;

                    if (accessConnection.State == ConnectionState.Closed)
                        accessConnection.Open();
                    OleDbCommand rootNodeCommand =
                        new OleDbCommand("SELECT nodeid, url, name FROM SiteMap WHERE parentnodeid IS NULL",
                                         accessConnection);
                    OleDbDataReader rootNodeReader = rootNodeCommand.ExecuteReader();

                    if(rootNodeReader.HasRows) {
                        rootNodeReader.Read();
                        rootNodeId = rootNodeReader.GetInt32(0);
                        // Create a SiteMapNode that references the current StaticSiteMapProvider.
                        rootNode   = new SiteMapNode(this,
                                                     rootNodeId.ToString(),
                                                     rootNodeReader.GetString(1),
                                                     rootNodeReader.GetString(2));

                    }
                    else return null;

                    rootNodeReader.Close();
                    // Select the child nodes of the root node.
                    OleDbCommand childNodesCommand =
                        new OleDbCommand("SELECT nodeid, url, name FROM SiteMap WHERE parentnodeid = ?",
                                         accessConnection);
                    OleDbParameter rootParam = new OleDbParameter("parentid", OleDbType.Integer);
                    rootParam.Value = rootNodeId;
                    childNodesCommand.Parameters.Add(rootParam);

                    OleDbDataReader childNodesReader = childNodesCommand.ExecuteReader();

                    if (childNodesReader.HasRows) {

                        SiteMapNode childNode = null;
                        while(childNodesReader.Read()) {
                            childNode =  new SiteMapNode(this,
                                                         childNodesReader.GetInt32(0).ToString(),
                                                         childNodesReader.GetString(1),
                                                         childNodesReader.GetString(2));

                            // Use the SiteMapNode AddNode method to add
                            // the SiteMapNode to the ChildNodes collection.
                            AddNode(childNode, rootNode);
                        }
                    }

                    childNodesReader.Close();
                    accessConnection.Close();
                }
                return rootNode;
            }
        }
    }
}


Finally, the AccessSiteMapProvider is configured as the default provider in the following Web.config file.

<configuration>
  <system.web>
    <siteMap defaultProvider="AccessSiteMapProvider">
     <providers>
       <add 
         name="AccessSiteMapProvider"
         type="Samples.AspNet.AccessSiteMapProvider,Samples.AspNet "
         accessSiteMapConnectionString="PROVIDER=MICROSOFT.JET.OLEDB.4.0;DATA SOURCE=sitemap.mdb "/>
     </providers> 
    </siteMap>
  </system.web>
</configuration>

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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