ViewDataDictionaryExtensions Class

Definition

Namespace

Cuemon.Extensions.AspNetCore.Mvc

Assemblies

Cuemon.Extensions.AspNetCore.Mvc.dll

Source

src/Cuemon.Extensions.AspNetCore.Mvc/ViewDataDictionaryExtensions.cs

Extension methods for the ViewDataDictionary class. Experimental.

public static class ViewDataDictionaryExtensions

Inheritance

object

ViewDataDictionaryExtensions

Examples

The following example follows the same pattern as the sample MVC app in the test project: controller actions populate breadcrumbs from the current model, and a shared Razor partial reads them back from . Three RegionController actions call AddBreadcrumbs with a RegionPageModel that holds hierarchical labels. A BreadcrumbPartial class then retrieves the breadcrumbs via GetBreadcrumbs and projects each into a readable string, demonstrating hierarchical navigation-data propagation in ASP.NET Core MVC.

using System.Collections.Generic;
using System.Linq;
using Cuemon.Extensions.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Razor;
using Microsoft.AspNetCore.Mvc.ViewFeatures;

namespace Cuemon.Extensions.AspNetCore.Mvc.DocExamples;

public sealed class RegionController : Controller
{
    public IActionResult Index()
    {
        var model = new RegionPageModel("Regions", "Northern Europe", "Danish");
        ViewData.AddBreadcrumbs(this, model, page => page.Labels);
        return View(model);
    }

    public IActionResult Region(string regionName, string regionDisplayName)
    {
        var model = new RegionPageModel("Regions", regionDisplayName, "Danish");
        ViewData.AddBreadcrumbs(this, model, page => page.Labels);
        return View("CultureCollection", model);
    }

    public IActionResult Culture(string regionName, string regionDisplayName, string cultureName)
    {
        var model = new RegionPageModel("Regions", regionDisplayName, cultureName);
        ViewData.AddBreadcrumbs(this, model, page => page.Labels);
        return View("Culture", model);
    }
}

public sealed class BreadcrumbPartial
{
    public IReadOnlyList<string> Render(ViewDataDictionary viewData, IRazorPage currentPage)
    {
        return viewData
            .GetBreadcrumbs(currentPage)
            .Select(link => $"{link.Label} ({link.ControllerName}/{link.ActionName})")
            .ToList();
    }
}

public sealed class RegionPageModel
{
    public RegionPageModel(params string[] labels)
    {
        Labels = labels;
    }

    public IReadOnlyList<string> Labels { get; }
}

Methods

Name	Description
AddBreadcrumbs<T>(ViewDataDictionary, Controller, T, Func<T, IEnumerable<string>>)	Adds a sequence of Breadcrumb objects to the specified viewData.
GetBreadcrumbs(ViewDataDictionary, IRazorPage)	Gets a sequence of Breadcrumb objects from the specified viewData.