Extension points

MvcSiteMapProvider is built wih extensibility in mind. All extension point contracts are defined in the MvcSiteMapProvider.Extensibility namespace. The sample application on the downloads page contains several custom implementations of these extension points.

The following extension points are available:

Global extension points (valid for the entire provider and all nodes)

These extension points can be defined when Registering the provider or by using dependency injection.

Node key generator

Keys for sitemap nodes are usually automatically generated by the MvcSiteMapProvider core. If, for reasons of accessing sitemap nodes from code, the generated keys should follow other naming rules, a custom MvcSiteMapProvider.Extensibility.INodeKeyGenerator implementation can be written.

Controller type resolver

In order to resolve a controller type and action method related to a specific sitemap node, a MvcSiteMapProvider.Extensibility.IControllerTypeResolver is used. This should normally not be extended, however if you want to make use of other systems for resolving controller types and action methods, this is the logical extension point.

Action method parameter resolver

Action method parameters are resolved by using ASP.NET MVC's ActionDescriptor class. If you want to use a custom system for this, a MvcSiteMapProvider.Extensibility.IActionMethodParameterResolver implementation can be specified.

ACL module

To determine whether a sitemap node is accessible to a specific user, a MvcSiteMapProvider.Extensibility.IAclModule implementation is used. MvcSiteMapProvider uses two of these modules by default: access is granted or denied by checking for [Authorize] attributes on action methods, followed by the roles attribute that can be specified in the sitemap XML.

URL resolver

URLs are generated by leveraging a MvcSiteMapProvider.Extensibility.ISiteMapNodeUrlResolver implementation. If, for example, you want all URLs generated by MvcSiteMapProvider to be in lowercase text, a custom implementation can be created.

Visibility provider

In some situations, nodes should be visible in the breadcrumb trail but not in a complete sitemap. This can be solved using the MvcSiteMapProvider.Extensibility.ISiteMapNodeVisibilityProvider extension point that can be specified globally for every node in the sitemap or granularly on a specific sitemap node. A sample is available on the Advanced node visibility page.

SiteMapProvider event handler

A class implementing MvcSiteMapProvider.Extensibility.ISiteMapProviderEventHandler can be registered to handle specific events, such as when adding a SiteMapNode.

Node-specific extension points (valid for a single node)

These extension points can be defined when Creating a first sitemap.

Dynamic node provider

In many web applications, sitemap nodes are directly related to content in a persistent store like a database.For example, in an e-commerce application, a list of product details pages in the sitemap maps directly to the list of products in the database. Using dynamic sitemaps, a small class implementing MvcSiteMapProvider.Extensibility.IDynamicNodeProvider or extending MvcSiteMapProvider.Extensibility.DynamicNodeProviderBase can be provided to the MvcSiteMapProvider offering a list of dynamic nodes that should be incldued in the sitemap. This ensures the product pages do not have to be specified by hand in the sitemap XML.

A sample can be found on the Dynamic sitemaps page.

URL resolver

URLs are generated by leveraging a MvcSiteMapProvider.Extensibility.ISiteMapNodeUrlResolver implementation. If, for example, you want the URL for a sitemap node generated by MvcSiteMapProvider to be in lowercase text, a custom implementation can be created.

Visibility provider

In some situations, nodes should be visible in the breadcrumb trail but not in a complete sitemap. This can be solved using the MvcSiteMapProvider.Extensibility.ISiteMapNodeVisibilityProvider extension point that can be specified globally for every node in the sitemap or granularly on a specific sitemap node. A sample is available on the Advanced node visibility page.