Navigation in DD4T

There always been a question on What is the best approach for building navigation with DD4T and ASP.NET MVC?

Answer is: There is TridionSiteMapProvider as part of the DD4T.Mvc project, which can be used out of the box. The  DD4T.Examples.Templates project also have a example on how Sitemap can be generated from the template (TBB)

Many organization will have different kinds of navigation structure, It can be from very simple structure or it can be a heavily complex in nature. In this article you can see how the default SitemapProvider can be used and how we could customize to achieve complex Navigations like Megamenu or similar using TridionSiteMapProvider.

Setting up the default TridionSiteMapProvider

The only configuration you would need to do in web.config is set the your default sitemap provider is as below.

<system.web>
  <siteMap defaultProvider="TridionSiteMapProvider" enabled="true">
    <providers>
      <clear/>
      <add name="TridionSiteMapProvider" type="DD4T.Mvc.Providers.TridionSiteMapProvider, DD4T.Mvc"/>
    </providers>
  </siteMap>
</system.web>

By default the sitemap path url looks in /system/sitemap/sitemap.xml, or based on web config.

In the example project, you have an Html extension to render the sitemap, it will return just the Html list. This helper can be called as @Html.SiteMapMenu(MenuType.Top)

In simple, it works as below diagram.

Customizing the default TridionSiteMapProvider

The TridionSiteMapProvider out of box is handling most of the scenarios; Sometime when we work with Mega menu or complex navigation, we might have the situation to handle more data other than normal sitemap node attributes. Below I am intent to explain how we could customize the TridionSiteMapProvider.
I have a custom TBB which generate a sitemap.xml or navigation.xml looks something like below by navigating the structure.

<root>
  <node id="tcm:8-4450-4" title="010. Personal" url="/en/personal/" description="tcm:8-337-64" compTitle="Personal Site" vanityURL="">
   <navTitle>Personal</navTitle>
    <NavConf>
      <NavUseFulLinks>
        <UseFulLinks>
          <Links>
            <Title>Utility Links for Personal</Title><TitleComponentLink>tcm:8-1224</TitleComponentLink>
            <Links>
              <LinkText>Some Text</LinkText>
              <ComponentLink>tcm:8-1000</ComponentLink>
            </Links>
            <Links>
              <LinkText>Some title text</LinkText>
              <ComponentLink>tcm:8-1018</ComponentLink>
        </Links>
            <Links>
              <LinkText>Some Title Text</LinkText>
              <ComponentLink>tcm:8-1950</ComponentLink>
            </Links></Links>
        </UseFulLinks>
      </NavUseFulLinks>
    </NavConf>
  </node>
</root>

In above xml, I have additional Node named NavConf with some more utilities links, which are obtained from Page Metadata. In such scenarios we could add the custom property to TridionSiteMapNode and then we can customize our sitemap helper to return the custom view template based on request.

In above scenario I have add a new Property named NavConf, in the class TridionSiteMapNode, and then In the TridionSiteMapProvider.cs class, I have customized the CreateNodeFromElement method to looks like below,

SiteMapNode childNode = new TridionSiteMapNode(this,
element.Attribute("id").Value, //key
uri,
element.Attribute("url") != null ? element.Attribute("url").Value : "", //url
element.Attribute("title") != null ? element.Attribute("title").Value : "", //title
element.Attribute("description") != null ? element.Attribute("description").Value : "", //description
null, //roles
attributes, //attributes
null, //explicitresourceKeys
null
)
{
Level = currentLevel,
NavConf = element.Element("NavConf") != null ? element.Element("NavConf") : null
}; 

The default navigation Helper class can be customized more generic so that we can customize the html in the view rather than in the Helper class. The extension CreateHtmlHelperForModel below will return the template view from the shared template folder based on the request e.g: Top, Left or Full. Only concern is you should have the below views on the Shared folder, because the Template will look for the view in DisplayTemplate Folder.

Creating NavigationHelper class

  public static class NavigationHelper
  {
      
        public static MvcHtmlString Navigation(this HtmlHelper helper,SiteMapNode rootNode, IPage page, NavigationTypes navigationType, string navigationXml = "/system/include/navigation.xml")
        {
            var langauge = helper.ViewContext.RouteData.Values["language"] as string;
            navigationXml = string.Format("/{0}/{1}", langauge, "system/include/navigation.xml");
            string template = string.Empty;
            switch (navigationType)
            {
                case NavigationTypes.Top:
                    template = "TopNavigation";
                    break;
                case NavigationTypes.Left:
                    template = "LeftNavigation";
                    break;
                case NavigationTypes.Right:
                    template = "RightNavigation";
                    break;
            }

         //   XmlDocument model = Utilities.GetXmlFile(navigationXml);

            var navigationHelper = new NavigationHtmlHelper(helper);
            return navigationHelper.CreateHtmlHelperForModel(rootNode).DisplayFor(x => rootNode, template,
                new
                {
                    NavParent = page.StructureGroup.Id,
                    PageUri = page.Id,
                    PublicationUri = page.Publication.Id
                }
            );
        }
    }

    public enum NavigationTypes
    {
        Top,
        Left,
        Bottom,
        Right,
        Breadcrum,
        Title,
        Canonical
    }

    public class NavigationHtmlHelper
    {
        /// <summary>
        /// Gets or sets the HTML helper.
        /// </summary>
        /// <value>The HTML helper.</value>
        public HtmlHelper HtmlHelper { get; protected set; }

        /// <summary>
        /// Initializes a new instance of the <see cref="MvcSiteMapHtmlHelper"/> class.
        /// </summary>
        /// <param name="htmlHelper">The HTML helper.</param>
        /// <param name="provider">The sitemap.</param>
        public NavigationHtmlHelper(HtmlHelper htmlHelper)
        {
            if (htmlHelper == null)
                throw new ArgumentNullException("htmlHelper");

            HtmlHelper = htmlHelper;

        }

        /// <summary>
        /// Creates the HTML helper for model.
        /// </summary>
        /// <typeparam name="TModel">The type of the model.</typeparam>
        /// <param name="model">The model.</param>
        /// <returns></returns>
        public HtmlHelper<TModel> CreateHtmlHelperForModel<TModel>(TModel model)
        {
            return new HtmlHelper<TModel>(HtmlHelper.ViewContext, new ViewDataContainer<TModel>(model));
        }
    }

    public class ViewDataContainer<TModel>
       : IViewDataContainer
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="ViewDataContainer&lt;TModel&gt;"/> class.
        /// </summary>
        /// <param name="model">The model.</param>
        public ViewDataContainer(TModel model)
        {
            ViewData = new ViewDataDictionary<TModel>(model);
        }

        /// <summary>
        /// Gets or sets the view data dictionary.
        /// </summary>
        /// <value></value>
        /// <returns>The view data dictionary.</returns>
        public ViewDataDictionary ViewData { get; set; }
    }

In the view, we can have something like below as simple or as complex as based on requirement.

@model TridionSiteMapNode
@if (Model.HasChildNodes)
{
    <ul>
        @foreach (TridionSiteMapNode node in Model.ChildNodes)
        {
            <li><a href="@node.Url">@node.Title</a> </li>
        }
    </ul>
}

In short, we can easily customize the TridionSitemapNode to use it as they way we want for simple or complex navigations.