I am trying to implement custom routing on an asp.net core application.
The desired result is the following:
http://Site_URL/MyController/Action/{Entity_SEO_Name}/
Entity_SEO_Name parameter will be a unique value saved into the database that it is going to help me identify the id of the entity that I am trying to display.
In order to achieve that I have implemented a custom route:
routes.MapMyCustomRoute(
name: "DoctorDetails",
template: " {controller=MyController}/{action=TestRoute}/{name?}");
public class MyTemplateRoute : TemplateRoute
{
public override async Task RouteAsync(RouteContext context)
{
//context.RouteData.Values are always empty. Here is the problem.
var seo_name = context.RouteData.Values["Entity_SEO_Name"];
int entityId = 0;
if (seo_name != null)
{
entityId = GetEntityIdFromDB(seo_name);
}
//Here i need to have the id and pass it to controller
context.RouteData.Values["id"] = entityId;
await base.RouteAsync(context);
}
}
My controller actionresult:
public ActionResult TestRoute(int id)
{
var entity = GetEntityById(id);
return Content("");
}
The problem with this approach is that the context.RouteData.Values are always empty.
Any ideas on how to move forward with this one ?
Your solution too complicated. You can have route template like
template: "{controller=Home}/{action=Index}/{seo?}"
and controller action just like
public ActionResult TestRoute(string seo)
{
var entity = GetEntityBySeo(seo);
return Content("");
}
It is enough, asp.net mvc is smart enough to bind seo variable to the parameter from url path.
Related
I want to switch my code to an async implementation. When I want to do this then I notice that my related data gets not set automatically after I retrieve them like it used to do it.
This is the initial function that gets called from an API controller. I used the AddDbContext function to add the dbcontext class via dependency injection into my controller:
public async Task<Application> GetApplicationById(AntragDBNoInheritanceContext dbContext, int id)
{
List<Application> ApplicationList = await dbContext.Applications.FromSqlRaw("Exec dbo.GetApplication {0}", id).ToListAsync();
Application Application = ApplicationList.First();
if(Application != null)
{
await CategoryFunctions.GetCategoryByApplicationID(Application.Id);
}
}
The GetCategoryByApplicationId function loads the related category of an application which is a many to one relation between Category and Application:
public async Task<Category> GetCategoryByApplicationID(int applicationID)
{
var optionsBuilder = new DbContextOptionsBuilder<AntragDBNoInheritanceContext>();
optionsBuilder.UseSqlServer(ApplicationDBConnection.APPLICATION_CONNECTION);
using (var dbContext = new AntragDBNoInheritanceContext(optionsBuilder.Options))
{
List<Category> category = await dbContext.Categories.FromSqlRaw("Exec GetApplicationCategory {0}", applicationID).ToListAsync();
if (category.Any())
{
return category.First();
}
}
return null;
}
When I want to retrieve an application then the field Category is not set. When I did not use async/await it would set the category automatically for me. Of course I could just return the Category Object from the GetCategoryByApplicationId and then say:
Application.Category = RetrievedFromDbCategory;
But this seems a bit unmaintainable compared to the previous behaviour. Why does this happen now and can I do something about it? Otherwise I don't see much benefits on using async/await .
I'm trying to create a simple feature to make the first action act like the second one.
public IActionResult GetMessage()
{
return "message";
}
public IActionResult GetMessageDataModel()
{
return new MessageDataModel("message");
}
First idea came to my mind was to extend SystemTextJsonOutputFormater, and wrap context.Object with my data model in WriteResponseBodyAsync, but the action is marked sealed.
Then I tried to override WriteAsync but context.Object doesn't have protected setter, either.
Is there anyway I can achieve this by manipulating OutputFormatter?
Or I have another option instead of a custom OutputFormatter?
for some reason they prefer every response in a same format like {"return":"some message I write.","code":1}, hence I want this feature to achieve this instead of creating MessageDataModel every time.
Based on your description and requirement, it seems that you'd like to generate unified-format data globally instead of achieving it in each action's code logic. To achieve it, you can try to implement it in action filter, like below.
public class MyCustomFilter : Attribute, IActionFilter
{
public void OnActionExecuted(ActionExecutedContext context)
{
// implement code logic here
// based on your actual scenario
// get original message
// generate new instance of MessageDataModel
//example:
var mes = context.Result as JsonResult;
var model = new MessageDataModel
{
Code = 1,
Return = mes.Value.ToString()
};
context.Result = new JsonResult(model);
}
Apply it on specific action(s)
[MyCustomFilter]
public IActionResult GetMessage()
{
return Json("message");
}
I searched, but did't really found articles on how to implement pagination logic in an ASP.NET WebAPI Core 2.1 application...
I have the following
[Route("api/[controller]")]
[ApiController]
[EnableCors("AllowMyOrigin")]
public class EntriesController : ControllerBase
{
private readonly EntriesContext _context;
public EntriesController(EntriesContext context) {
_context = context;
if (_context.Entries.Count() == 0) {
_context.Entries.Add(new Entry { From = "default", To = "default" });
_context.SaveChanges();
}
}
[HttpGet]
public ActionResult<List<Entry>> GetAll() {
return _context.Entries.ToList();
}
[HttpGet("{id}", Name = "GetEntry")]
public ActionResult<Entry> GetById(long id) {
var item = _context.Entries.Find(id);
if (item == null) { return NotFound(); }
return item;
}
Now, I want my entries to be paginated using new params page and pageSize. Say
/api/entries?pageSize=3&page=2
Should I use the GetAll() method by adding some http params to it, or rather create a new method? There are no much sense to use page without pageSize, how do I manage this?
There are libraries, such as X.PagedList you can use. Frankly, pagination is pretty straight-forward, so you may not even need that. All you need to know is the page number, page size, and total number of results. The page number obvious comes from the request, and the page size can as well, if you want it customizable, or you can hard-code it.
public ActionResult<List<Entry>> GetAll(int page = 1, int size = 10)
Then, you can use Skip and Take to get the data for a particular page:
var query = _context.Entries;
var entries = await query.Skip((page - 1) * size).Take(size).ToListAsync();
var count = await query.CountAsync();
Then, all you need to know is the total number of pages, which can be calculated simply via:
var totalPages = (int)Math.Ceil(count / (float)size);
From that, you can calculate anything else you need, i.e.:
var firstPage = 1; // obviously
var lastPage = totalPages;
var prevPage = page > firstPage ? page - 1 : firstPage;
var nextPage = page < lastPage ? page + 1 : lastPage;
First of all, you can default you pageSize value to something:
[HttpGet]
public ActionResult<List<Entry>> GetAll(int? page = null, int? pageSize = 10)
{
if (!page.HasValue) {
return _context.Entries.ToList();
}
// do you pagination here
}
But you also may look at OData, it seems to be your case. It will allow you to query your data using http params, e.g.: /api/Entires?$skip=5&$top=5
I've just created a PagingTagHelper for ASP.NET Core Razor pages to render paging control easily with just the basic parameters, the simplest setup looks like below:
<paging total-records="Model.TotalRecords" page-no="Model.PageNo">
</paging>
all you need is to provide total records and page number for it to run. The default query string parameters are "p" for page number and "s" for page size, however, it is customizable/localizable, you can change all the settings according to your own requirements.
you can install it from nuget:
Install-Package LazZiya.TagHelpers -Version 1.0.2
then you need to add the tag helper to the _ViewImports.cshtml file:
#addTagHelper *, LazZiya.TagHelpers
http://ziyad.info/en/articles/21-Paging_TagHelper_for_ASP_NET_Core
more documentations and live demo will be available soon.
Currently I am looking for best practice in handling conditions inside the controller actions in asp.net mvc. For example -
public ActionResult Edit(int Id = 0)
{
var Item = _todoListItemsRepository.Find(Id);
**if (Item == null)
return View("NotFound");
if (!Item.IsAuthorized())
return View("NotValidOwner");**
return View("Edit", Item);
}
The above two conditions marked in bold is used in other actions inside the controller. So, in order not to repeat these conditions in all the actions. I have used the below approach.
[HttpGet]
[Authorize]
[ModelStatusActionFilter]
public ActionResult Edit(int Id = 0)
{
var Item = _todoListItemsRepository.Find(Id);
return View("Edit", Item);
}
public class ModelStatusActionFilterAttribute : ActionFilterAttribute
{
private readonly ITodoListItemsRepository _todoListItemsRepository;
public ModelStatusActionFilterAttribute()
: this(new TodoListItemsRepository())
{
}
public ModelStatusActionFilterAttribute(ITodoListItemsRepository todoListItemsRepository)
{
_todoListItemsRepository = todoListItemsRepository;
}
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
try
{
var Id = Convert.ToInt32(filterContext.RouteData.Values["Id"]);
var Item = _todoListItemsRepository.Find(Id);
if (Item == null)
{
filterContext.Result = new ViewResult() { ViewName = "NotFound" };
}
else if (!Item.IsAuthorized())
{
filterContext.Result = new ViewResult() { ViewName = "NotValidOwner" };
}
}
catch
{
}
}
}
I am unsure if this is the best practice in handling such scenarios. So, could someone please advise ?
Regards,
Ram
usually you don't use action filter for so-called business logic of your web application - this is what the controllers are for. Action filter are rather for the whole stuff which is external to the actual logic - common case is logging, performance measurement, checking if user is authenticated / authorized (I don't think this is your case, although you call IsAuthorized method on the "Item").
Reducing code is generally good thing but in this case, I don't think putting the logic to action is a good way, because you;ve actually made it a bit unreadable, and unreadable code is in my opinon much worse than repeated code.
Also, specifically in your case, for all valid items you actually call the _todoListItemsRepository.Find() twice (for each valid item), which might be costly if this is some webservice call or db lookup.
If the code is just repeated throughout the actions, make a method out of it like:
private View ValidateItem(Item) {
if (Item == null)
return View("NotFound");
if (!Item.IsAuthorized())
return View("NotValidOwner");
return null; }
I am unsure on how I should be naming my View pages, they are all CamelCase.cshtml, that when viewed in the browser look like "http://www.website.com/Home/CamelCase".
When I am building outside of .NET my pages are named like "this-is-not-camel-case.html". How would I go about doing this in my MVC4 project?
If I did go with this then how would I tell the view to look at the relevant controller?
Views/Home/camel-case.cshtml
Fake edit: Sorry if this has been asked before, I can't find anything via search or Google. Thanks.
There are a few ways you can do this:
Name all of your views in the style you would like them to show up in the url
This is pretty simple, you just add the ActionName attribute to all of your actions and specify them in the style you would like your url to look like, then rename your CamelCase.cshtml files to camel-case.cshtml files.
Use attribute routing
Along the same lines as above, there is a plugin on nuget to enable attribute routing which lets you specify the full url for each action as an attribute on the action. It has convention attributes to help you out with controller names and such as well. I generally prefer this approach because I like to be very explicit with the routes in my application.
A more framework-y approach
It's probably possible to do something convention based by extending the MVC framework, but it would be a decent amount of work. In order to select the correct action on a controller, you'd need to map the action name on its way in to MVC to its CamelCase equivalent before the framework uses it to locate the action on the controller. The easiest place to do this is in the Route, which is the last thing to happen before the MVC framework takes over the request. You'll also need to convert the other way on the way out so the urls generated look like you want them to.
Since you don't really want to alter the existing method to register routes, it's probably best write a function in application init that loops over all routes after they have been registered and wraps them with your new functionality.
Here is an example route and modifications to application start that achieve what you are trying to do. I'd still go with the route attribute approach however.
public class MvcApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
WebApiConfig.Register(GlobalConfiguration.Configuration);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
WrapRoutesWithNamingConvention(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
AuthConfig.RegisterAuth();
}
private void WrapRoutesWithNamingConvention(RouteCollection routes)
{
var wrappedRoutes = routes.Select(m => new ConventionRoute(m)).ToList();
routes.Clear();
wrappedRoutes.ForEach(routes.Add);
}
private class ConventionRoute : Route
{
private readonly RouteBase baseRoute;
public ConventionRoute(RouteBase baseRoute)
: base(null, null)
{
this.baseRoute = baseRoute;
}
public override RouteData GetRouteData(HttpContextBase httpContext)
{
var baseRouteData = baseRoute.GetRouteData(httpContext);
if (baseRouteData == null) return null;
var actionName = baseRouteData.Values["action"] as string;
var convertedActionName = ConvertHyphensToPascalCase(actionName);
baseRouteData.Values["action"] = convertedActionName;
return baseRouteData;
}
private string ConvertHyphensToPascalCase(string hyphens)
{
var capitalParts = hyphens.Split('-').Select(m => m.Substring(0, 1).ToUpper() + m.Substring(1));
var pascalCase = String.Join("", capitalParts);
return pascalCase;
}
public override VirtualPathData GetVirtualPath(RequestContext requestContext, RouteValueDictionary values)
{
var valuesClone = new RouteValueDictionary(values);
var pascalAction = valuesClone["action"] as string;
var hyphens = ConvertPascalCaseToHyphens(pascalAction);
valuesClone["action"] = hyphens;
var baseRouteVirtualPath = baseRoute.GetVirtualPath(requestContext, valuesClone);
return baseRouteVirtualPath;
}
private string ConvertPascalCaseToHyphens(string pascal)
{
var pascalParts = new List<string>();
var currentPart = new StringBuilder();
foreach (var character in pascal)
{
if (char.IsUpper(character) && currentPart.Length > 0)
{
pascalParts.Add(currentPart.ToString());
currentPart.Clear();
}
currentPart.Append(character);
}
if (currentPart.Length > 0)
{
pascalParts.Add(currentPart.ToString());
}
var lowers = pascalParts.Select(m => m.ToLower());
var hyphens = String.Join("-", lowers);
return hyphens;
}
}
}