I have this Action:
public ActionResult AddCategory(Category newCategory)
{
...//newCategory.Name is filled up
return new Json(true);
}
And a view that post at this Action:
#using(Html.BeginForm)
{
#Html.TextBoxFor(Model.Name)
.....
}
Now I want to reuse this Action, but in another page.
But in this new View, I already have a Html.TextBox("name") at another . Its a kind of DashBoard.
This new View, have a property NewCategory inside the Model:
public class MyViewModel
{
public Category NewCategory{get;set;}
}
If I do this:
#using(Ajax.BeginForm)
{
#Html.TextBoxFor(Model.NewCategory.Name)
.....
}
Wont work, because my action dont expect any Prefix, in this case NewCategory.
Of course, I can manually call the Action, but doing this I lost built-in validation(I am using DataAnnotation with Unobtrusive validation).
Its a scenario that I fall from time to time
The best choice that I have now is duplicate the Action:
public ActionResult AddCategory([Bind(Prefix="NewCategory")]Category category)
{
...
return new Json(true);
}
Call Html.RenderAction to reuse action result in other views, and pass name parameter to it for your model, for example:
Use Html.RenderAction("AddCategory", new {name = Model.CategoryName})
The solution is to create another method with the "same" assignature:
[ActionName("AddCategory")]
public ActionResult AddCategory2([Bind(Prefix="NewCategory2")]Category category)
{
...
return new Json(true);
}
what i understand from your question is that you are in some View X and you want to render AddCategory View inside this view and Model of View X contains NewCategory which is of type Category and accepted by AddCategory View as model. if so you just have to call render partial in your View X
<%Html.RenderPartial("AddCategory", Model.NewCategory);%>
Related
I have an app with many widgets and their content depends on the user requesting specific route. Simply put: if widget action is requested, its content must be rendered, otherwise it's empty. Consider routes/actions like this:
~/MyApp/Index -> without model; app HTML, without any widgets
~/MyApp/Foo/{id} -> uses FooModel; if ModelState is valid, returns
Index HTML with injected partial view of Foo's widget to div#foo;
otherwise redirects to Index.
~/MyApp/Bar/{id} -> same as Foo, but different model and widget
My foo action :
public ActionResult Foo(string id) {
if (ModelState.IsValid) {
var response = FooService.GetData(id);
// Inject Foo widget to Index
}
return RedirectToAction("Index");
}
I know that it is possible to use ViewBag or other means to send variables and using the condition to decide whether to render partial view or not. But... there should be a better way to do this, right?
I use MVC's Html.RenderActionResult when I want to build shared views with non-trivial binding logic (calling the database, composing complex objects, etc). The binding logic for each widget is contained in a PartialViewResult method, which is called from the *.cshtml file using Html.RenderAction().
ContentController:
public ActionResult Index(int id)
{
var indexViewModel = new IndexViewModel
{
Id = id,
Title = "My Title",
SubHeader = "Wow its 2016"
};
return View(indexViewModel);
}
public PartialViewResult PopularContent(int id)
{
var popularContentViewModel = new List<PopularContentViewModel>();
// query by id to get popular content items
return PartialView("_PopularContent", popularContentViewModel);
}
public PartialViewResult Widget2(int id)
{
return PartialView("_Widget2Partial");
}
Index.cshtml:
#model StackOverflow.RenderAction.ViewModels.IndexViewModel
<h1>#Model.Title</h1>
<h2>#Model.SubHeader</h2>
--RenderAction will call out to the specified route.
--Note the use of the Id parameter from the viewmodel.
#{Html.RenderAction("PopularContent", "Content", new {Model.Id});}
ASP.NET MVC Attribute Routing could a be a nice solution for this:
In your controller:
public class WidgetController : Controller
{
[Route("myapp/foowidget", Name = "FooWidget")]
public ActionResult FooWidget()
{
//create any model and return any view or partial or redirect
}
[Route("myapp/boowidget/{id:int}", Name = "BooWidget")]
public ActionResult BooWidget(int id)
{
//create any model and return any view or partial or redirect
}
}
And then in a View, you can call the Route by name:
#Url.RouteUrl("FooWidget")
or
#Url.RouteUrl("BooWidget")
or
#Html.RenderPartial("FooWidget")
#Url.RouteUrl("BooWidget") will render or concatenate the id that is in current url, if url is /myapp/something/id, because of your Route attribute definition: "myapp/boowidget/{id:int}". In fact #Url.RouteUrl("BooWidget") might extract the id from any current url of the format /controllerName/action/id, though you will have to test for sure.
And notice how you can have a separation of concerns with your WidgetController and your url Routes are not dependent on that controller's name in any way. That is a nice feature of Attribute Routing, you can declare custom routes as well as organize your controllers and break from nameing convention dependency of a controllerName being part of the url controllerName/action a user sees in their browser.
In regards to Html.RenderPartial, I am not sure if RenderPartial "connects" or will be able to route to your RouteName like "FooWidget". If it does great.
If not your solution is this:
public class WidgetController : Controller
{
public ActionResult FooWidget()
{
//model, you choose, return a partial
}
public ActionResult RedirectUser()
{
//do a redirect
}
public ActionResult BooWidget()
{
//any model, any partial
}
public ActionResult BooWidget(int id)
{
//any model, any partial
}
}
Each method in your controller is single purpose, has a distinct signature and does one thing, no conditions to pass in and no decisions required.
I have a controller where all of the action methods contain the same code:
[ActionName("pretty-url")]
public ActionResult Something() {
return PartialView();
}
[ActionName("another-pretty-url")]
public ActionResult SomethingElse() {
return PartialView();
}
I name my partial views in the pretty-url.cshtml format, and these get picked up fine and everything works.
As every action in the controller will always do exactly the same thing and return the same thing, I would like to just have my controller look for the correctly-named view and return it as above, without me having to explicitly implement it.
How would I do that?
TIA
I would create a single action and pass the view name as parameter.
public ActionResult Something(string viewName)
{
return PartialView(viewName);
}
I would add a new method to my controller with a string parameter and use it to load the correct partial view.
public ActionResult Show(string PartialName)
{
return PartialView(PartialName);
}
Now instead of using http://your.domain/pretty_url you will have to use http://your.domain/show/pretty_url but this will work with any new partial view you add later on.
I want to return an object on HTTPGet method and different object in HTTPPost method of the same action method in the controller, but i dont know what to write in the view, which model to get.
Here is the controller code , i have been trying
[HttpGet]
public ActionResult Create()
{
var intSrNo = Convert.ToInt64(TempData["sr_no"]);
MEntities obj_entity = new MEntities();
UDP_get_a_Result obj_proc = obj_entity.UDP_get_a(intSrNo).SingleOrDefault();
return View(obj_proc);
}
[HttpPost]
public ActionResult Create(Table_a obj_a)
{
if (ModelState.IsValid)
{
db.Table_a.AddObject(obj_a);
db.SaveChanges();
return RedirectToAction("Index");
}
return View(obj_a);
}
i'm confused which model to write in view.(Table_a or UDP_get_a_Result) and i want both HttpGet to show values when the page is loaded and HttpPost when the submit is clicked.
View
#model ABC.models.Table_a
#{
ViewBag.Title = "Create";
}
A view can only be strongly typed to a single class. You cannot have different controller actions returning the same view and passing different models to this view. You could use view models: define a class which will hold all the information necessary for this view and then have your controller actions fill this view models and pass it to this view.
I think it would work to have the view typed to some base class (object) and then cast the model to whatever you needed it to be based on get/post. I wouldn't want to maintain it tho. :-D
I noticed that in the NerdDinner application that if the ModelState is invalid for a dinner, it merely returns the view for the model:
if (ModelState.IsValid) {
...
return RedirectToAction("Details", new { id=dinner.DinnerID });
}
return View(dinner);
However, in my application the model (a view model in this situation) contains multiple SelectLists. These lists are not instantiated at this point because this view model was just populated from the form submission. What is the recommended way to repopulate this SelectLists before sending them back to the user?
This is what I want my controller to do:
public ActionResult Save(MyModel model)
{
if (ModelState.IsValid)
{
businessClass.Save(model);
return RedirectToAction("Index", "Home");
}
// This won't work because model has uninstantiated SelectLists
return View("MyView", model);
}
I don't want to send the model to my business logic if the ModelState is invalid, but it doesn't seem to make sense to put SelectList population code in my controller. Should I create a public method in my business logic solely for doing this kind of stuff on my view model(s)?
Personally I like to keep it simple:-
[HttpGet]
public Edit(int id) {
EditForm form = new EditForm();
// Populate from the db or whatever...
PopulateEditPageSelectLists(form);
return View(form);
}
[HttpPost]
public Edit(EditForm form) {
if (ModelState.IsValid) {
// Do stuff and redirect...
}
PopulateEditPageSelectLists(form);
return View(form);
}
public void PopulateEditPageSelectLists(form) {
// Get lookup data from the db or whatever.
}
If the logic to populate the select lists is all kinds crazy it might be worthwhile moving to a separate class or whatever it but as a first step this is the best place to start.
You dont say how much reusability would you like. But personally, i like things "clear" (dont invading controller) and reausable as possible, and that in MVC means - filters.
Look at this :
public class SupplyLanguagesAttribute : System.Web.Mvc.ActionFilterAttribute
{
public override void OnActionExecuting(System.Web.Mvc.ActionExecutingContext filterContext)
{
filterContext.Controller.ViewData["languagesList"] =
someService.LoadLanguagesAsDictionary();
base.OnActionExecuting(filterContext);
}
}
then you just use it with every action method where you "might" need languages :
[SupplyLanguages]
public ActionResult DoSomething()
{
...
}
And then in view, you can use the data directly for DropDownList from ViewData, or you can even "wrap" this too (and avoid "magic strings" in views), with custom reusable DropDown :
public static MvcHtmlString LanguageDropDown(this HtmlHelper html, string name, object selectValue, bool defaultOption = false)
{
var languages = html.ViewData["languagesList"] as IDictionary<string,string>;
if (languages == null || languages.Count() == 0)
throw new ArgumentNullException("LanguageDropDown cannot operate without list of languages loaded in ViewData. Use SupplyLanguages filter.");
var list = new SelectList(languages, "Key", "Value", selectValue);
return SelectExtensions.DropDownList(html, name, list);
}
My controllers populate the SelectLists on my Model if the ModelState is not valid.
Following Separation of Concerns, your business classes shouldn't know anything about the view model at all. If your view needs a list of employees your controller gets a list of employees from your business layer and creates the SelectList that your view needs.
Example
public ActionResult Save(MyModel model)
{
if (ModelState.IsValid)
{
businessClass.Save(model);
return RedirectToAction("Index", "Home");
}
model.PossibleEmployees
= _employeeRepository.All().Select(e =>
new SelectListItem{Text=e.Name,
Value=e.Id});
return View("MyView", model);
}
Update
If your select list population code is determining WHICH options to present I think you probably should move that to a service in your business layer. If reusability is the big concern, rouen's answer looks like it has the most possibility for reuse.
I use to fill lists even when the model is invalid. One other possible solution is to have an action returning the json information and build the select via ajax. SOmetimes I've also resorted to static properties / cached collections. I guess it's always depending on the particular case.
PS: You can use a local Model in each action, so I can leave initialization inside the Model constructor. (often I override a base model with [NonAction] utilities as well).
For example, I have an Employee list used widely in your application.
I've added some utility method in a base controller to build up SelectListItems and the likes. Since each and every model inherits from the base, I've got them almost everywhere in the app. Of course the Collection is filled via a dedicated business objec.
What I do is I have a static function in a class that returns a SelectList. The method accepts an Enum value which defines which SelectList to return. In the View the DropDownList or DropDownListFor functions call this function to get the SelectList.
The static function looks like this:
class HelperMethods
{
enum LookupType {Users, Companies, States};
public static SelectList CommonSelectList(LookupType type, int? filterValue = null)
//filterValue can be used if the results need to be filtered in some way
var db = new WhateverEntities();
switch (type)
{
case LookupType.Users:
var list = db.Users.OrderBy(u => u.LastName).ToList()
return new SelectList(list, "ID", "FullName")
break;
case LookupType.Companies
var list = db.Companies.OrderBy(u => u.Name).ToList()
return new SelectList(list, "ID", "Name")
break;
//and so on...
}
}
}
And the view contains this:
#Html.DropDownListFor(m => m.UserID, HelperMethods.CommonSelectList(LookupType.Users))
This way the Model and Controller does not need code to configure a SelectList to send over to the View. It makes it very easy to reuse a SelectList that has already been configured. Also, if a View needs to loop through a list of objects, then this same function can be used to get a list for that. This is the simplest and most convenient way I found of doing this.
Class Student {
String Name {get; set}
//Extended property of the student
School Shooling {get; set;}
}
public StudentControlelr ()
{
public SchoolInfo (int? ID)
{
Student s = StudentRepository.GetStudentByID(id)
Return View ("Schooling/Index", s.Schooling);
}
}
for some reason i have to make this view as a shared view
// Views/Shared/schooling.ascx
Return View ("Schooling", s.Schooling);
This works but why not if its in a different view folder it won't work? Am I missing some thing here?
Please note that ASP.net novice.
Kind Regards
Vinay
You can redirect to the action:
return RedirectToAction("Action", "Controller");
The only issue here is that you cannot pass a model, but there are a couple ways to get around this:
Pass parameter and get the model upon load
return RedirectToAction("Action", "Controller", new { id = 1});
Pass the model using TempData
TempData["MyModel"] = s.Schooling;
return RedirectToAction("Action", "Controller");
This will work but a better solution would be to redirect to a different action:
return View ("~/Views/Schooling/Index.aspx", s.Schooling);
Note: You will need to change .aspx to your views extension if you are not using ASPX Views.