MVCSiteMapProvider dynamic nodes not showing

Question

I am currently implementing breadcrumb in a MVC3 Razor application, using Maartenba's MVC Sitemap Provider. The problem occurs when I try to create dynamic nodes, for the blog posts. What I want to achieve is to display Home>Blog for the blog page and Home>Blog>BlogPostTitle for the post page, where BlogPostTitle is the title of the currently displayed post. What I actually get is: Home>Blog both for the blog page and for any post page.

To test the dynamic nodes generation, I also included on the _Layout a call to @Html.MvcSiteMap().Menu(false, true, true). The displayed menu confirms that the nodes are correctly generated:

Home
About
Blog
- Article #1 title
- Article #2 title
Contact

Still, the @Html.MvcSiteMap().SiteMapPath() displays Home>Blog both for the blog page and for the articles.

Here is the code:

Sitemap:

<mvcSiteMapNode title="Home" controller="Home" action="Index">
    <mvcSiteMapNode title="About" controller="Home" action="About"/>
    <mvcSiteMapNode title="Blog" controller="BlogPost" action="Index" key="News" >
        <mvcSiteMapNode title="" controller="BlogPost" action="Details" dynamicNodeProvider ="MyApp.Helpers.BlogPostDynamicNodeProvider, myApp" />
    </mvcSiteMapNode>
    <mvcSiteMapNode title="Contact" controller="Home" action="Contact"/>
</mvcSiteMapNode>

Dynamic node provider:

public class BlogPostDynamicNodeProvider : DynamicNodeProviderBase
{
    public BlogPostRepository _repository = new BlogPostRepository();
    public List<BlogPost> articles = new List<BlogPost>();

    public override IEnumerable<DynamicNode> GetDynamicNodeCollection()
    {
        articles = _repository.FindAllBlogPosts();
        var returnValue = new List<DynamicNode>();

        foreach (var article in articles)
        {
            DynamicNode node = new DynamicNode();
            node.ParentKey = "News";
            node.Title = article.PostTitle;
            node.RouteValues.Add("id", article.Post_ID);
            returnValue.Add(node);
        }
        return returnValue;
    }

    public override CacheDescription GetCacheDescription()
    {
        return new CacheDescription("BlogPostDynamicNodeProvider")
        {
            SlidingExpiration = TimeSpan.FromMinutes(1)
        };
    }
}

BlogPostCOntroller

    public ViewResult Index(long? BlogPost_ID)
    {

        var BlogPostList = new PagedData<BlogPost>();
        BlogPostList.Data = repository.FindAllBlogPostsPaged(1, 3, 1);

        BlogPostList.NumberOfPages = Convert.ToInt32(Math.Ceiling((double)repository.NumberOfPosts(1) / 3));
        BlogPostList.CurrentPage = 1;

       BlogPost pBlogPost = new BlogPost();
            pBlogPost.PostDate = DateTime.Now;

            return View(new BlogPostPagedViewModel(pBlogPost, repository.FindAllBlogPosts()
                new SelectList(ctgRepository.FindAllBlogCategories(), "Category_ID", "Category_Name")));
    }

    [SiteMapPreserveRouteData]
    public ActionResult Details(long id)
    {
        BlogPost post = repository.FindABlogPostByID(id);
        return PartialView("_Details", post);
    }

_Layout

<div id="pagecontent">
    @Html.MvcSiteMap().Menu(false, true, true)   <!-- for test purpose only -->
    @Html.MvcSiteMap().SiteMapPath() 
    @Html.Partial("_PagedList", Model.BlogPostList)
</div><!-- page blogcontent -->

Blog Index view

<div id="blogcontent">
    @Html.Partial("_PagedList", Model.BlogPostList)
</div><!-- end blogcontent -->

Blog _PagedList partial view

@using (Ajax.BeginForm(new AjaxOptions { UpdateTargetId = "blogcontent", InsertionMode = InsertionMode.Replace }))
{
    foreach (var item in Model.Data)
    {
        <h2 class="posttitle">
            @Ajax.ActionLink(item.PostTitle, "Details", "BlogPost", new { id = item.Post_ID }, new AjaxOptions { UpdateTargetId = "blogcontent" }, null)            
        </h2>
    }
}

Details view

@model MyApp.Models.BlogPost
@using (Ajax.BeginForm(new AjaxOptions { UpdateTargetId = "blogcontent", InsertionMode = InsertionMode.Replace }))
{
    <div class="blogpost">
    ...
    </div>
}

_ Edit _ I discovered that, if I remove @Html.MvcSiteMap().SiteMapPath() from _Layout and place it instead in the blog Index view and in the Details view, the breadcrumb displays the current location correctly.

But that means I need to place it on every page from the project, which is in contradiction with the role of the _Layout shared view!

Where is the mistake in my code?

Xharze Xharze · Accepted Answer · 2012-10-12T11:00:33

Try setting Controller and Action when creating the DynamicNode:

DynamicNode node = new DynamicNode();
node.Controller = "ControllerName";
node.Action = "ActionName";
node.ParentKey = "News";
node.Title = article.PostTitle;
node.RouteValues.Add("id", article.Post_ID);
returnValue.Add(node);

This information is used to choose the correct route.

MVCSiteMapProvider dynamic nodes not showing

3 Answers