I'm using ASP.NET MVC 4. I am trying to pass data from one controller to another controller. I'm not getting this right. I'm not sure if this is possible?
Here is my source action method where I want to pass the data from:
public class ServerController : Controller
{
[HttpPost]
public ActionResult ApplicationPoolsUpdate(ServiceViewModel viewModel)
{
XDocument updatedResultsDocument = myService.UpdateApplicationPools();
// Redirect to ApplicationPool controller and pass
// updatedResultsDocument to be used in UpdateConfirmation action method
}
}
I need to pass it to this action method in this controller:
public class ApplicationPoolController : Controller
{
public ActionResult UpdateConfirmation(XDocument xDocument)
{
// Will add implementation code
return View();
}
}
I have tried the following in the ApplicationPoolsUpdate action method but it doesn't work:
return RedirectToAction("UpdateConfirmation", "ApplicationPool", new { xDocument = updatedResultsDocument });
return RedirectToAction("UpdateConfirmation", new { controller = "ApplicationPool", xDocument = updatedResultsDocument });
How would I achieve this?
HTTP and redirects
Let's first recap how ASP.NET MVC works:
When an HTTP request comes in, it is matched against a set of routes. If a route matches the request, the controller action corresponding to the route will be invoked.
Before invoking the action method, ASP.NET MVC performs model binding. Model binding is the process of mapping the content of the HTTP request, which is basically just text, to the strongly typed arguments of your action method
Let's also remind ourselves what a redirect is:
An HTTP redirect is a response that the webserver can send to the client, telling the client to look for the requested content under a different URL. The new URL is contained in a Location header that the webserver returns to the client. In ASP.NET MVC, you do an HTTP redirect by returning a RedirectResult from an action.
Passing data
If you were just passing simple values like strings and/or integers, you could pass them as query parameters in the URL in the Location header. This is what would happen if you used something like
return RedirectToAction("ActionName", "Controller", new { arg = updatedResultsDocument });
as others have suggested
The reason that this will not work is that the XDocument is a potentially very complex object. There is no straightforward way for the ASP.NET MVC framework to serialize the document into something that will fit in a URL and then model bind from the URL value back to your XDocument action parameter.
In general, passing the document to the client in order for the client to pass it back to the server on the next request, is a very brittle procedure: it would require all sorts of serialisation and deserialisation and all sorts of things could go wrong. If the document is large, it might also be a substantial waste of bandwidth and might severely impact the performance of your application.
Instead, what you want to do is keep the document around on the server and pass an identifier back to the client. The client then passes the identifier along with the next request and the server retrieves the document using this identifier.
Storing data for retrieval on the next request
So, the question now becomes, where does the server store the document in the meantime? Well, that is for you to decide and the best choice will depend upon your particular scenario. If this document needs to be available in the long run, you may want to store it on disk or in a database. If it contains only transient information, keeping it in the webserver's memory, in the ASP.NET cache or the Session (or TempData, which is more or less the same as the Session in the end) may be the right solution. Either way, you store the document under a key that will allow you to retrieve the document later:
int documentId = _myDocumentRepository.Save(updatedResultsDocument);
and then you return that key to the client:
return RedirectToAction("UpdateConfirmation", "ApplicationPoolController ", new { id = documentId });
When you want to retrieve the document, you simply fetch it based on the key:
public ActionResult UpdateConfirmation(int id)
{
XDocument doc = _myDocumentRepository.GetById(id);
ConfirmationModel model = new ConfirmationModel(doc);
return View(model);
}
Have you tried using ASP.NET MVC TempData ?
ASP.NET MVC TempData dictionary is used to share data between controller actions. The value of TempData persists until it is read or until the current user’s session times out. Persisting data in TempData is useful in scenarios such as redirection, when values are needed beyond a single request.
The code would be something like this:
[HttpPost]
public ActionResult ApplicationPoolsUpdate(ServiceViewModel viewModel)
{
XDocument updatedResultsDocument = myService.UpdateApplicationPools();
TempData["doc"] = updatedResultsDocument;
return RedirectToAction("UpdateConfirmation");
}
And in the ApplicationPoolController:
public ActionResult UpdateConfirmation()
{
if (TempData["doc"] != null)
{
XDocument updatedResultsDocument = (XDocument) TempData["doc"];
...
return View();
}
}
Personally I don't like to use TempData, but I prefer to pass a strongly typed object as explained in Passing Information Between Controllers in ASP.Net-MVC.
You should always find a way to make it explicit and expected.
I prefer to use this instead of TempData
public class Home1Controller : Controller
{
[HttpPost]
public ActionResult CheckBox(string date)
{
return RedirectToAction("ActionName", "Home2", new { Date =date });
}
}
and another controller Action is
public class Home2Controller : Controller
{
[HttpPost]
Public ActionResult ActionName(string Date)
{
// do whatever with Date
return View();
}
}
it is too late but i hope to be helpful for any one in the future
If you need to pass data from one controller to another you must pass data by route values.Because both are different request.if you send data from one page to another then you have to user query string(same as route values).
But you can do one trick :
In your calling action call the called action as a simple method :
public class ServerController : Controller
{
[HttpPost]
public ActionResult ApplicationPoolsUpdate(ServiceViewModel viewModel)
{
XDocument updatedResultsDocument = myService.UpdateApplicationPools();
ApplicationPoolController pool=new ApplicationPoolController(); //make an object of ApplicationPoolController class.
return pool.UpdateConfirmation(updatedResultsDocument); // call the ActionMethod you want as a simple method and pass the model as an argument.
// Redirect to ApplicationPool controller and pass
// updatedResultsDocument to be used in UpdateConfirmation action method
}
}
Related
I have 2 pages which can be accessed via these actions:
public class SearchEngineController : Controller
{
[Route("/search/{k}")]
public IActionResult Search(string k = "")
{
return View();
}
}
public class ChannelController : Controller
{
[Route("{name}")]
public IActionResult Index(string name = "")
{
return View();
}
}
Now, when I search something with a key (somekey), I want to redirect to url localhost:5000/search?k=somekey
Because we're working with channels (like Youtube's channels), so we need to classify the channel names, it should be unique. Example, a channel with a name mobifone can be accessed through localhost:5000/mobifone.
Everything may look ok until the name parameter (inside the Index action) cannot classify when a searched request is called. So, everytime I type localhost:5000/search?k=somekey, it will hit the Index action.
So, my temporary solution looks like this:
public class ChannelController : Controller
{
[Route("{name}")]
public IActionResult Index(string name = "")
{
if (name.ToLower() == "search")
{
// ~/Views/Shared/Search.cshtml
return View("Search");
}
return View();
}
}
It may solve the problem but.... I don't like it. Because I don't want to nest and excute the search query inside ChannelController. It's not a part of channel. A channel may contain:
- Id
- Name
- DisplayName
- FounderId
- ...
In the middleware, _channelManager shouldn't have a searched engine member which can return everything in the world, such as:
- Channel information
- List of channels
- User profile
- A post content
- List of posts
- ...
Is there any way better than mine?
The issue is that you're not actually using a correct route. You've defined the search route as "/search/{k}", which then means that you need something like /search/somekey to actually hit it. What you're requesting is /search?k=somekey, which doesn't match the search route, and is likely simply falling back to your default route, which just so happens to be this ChannelController.Index action. If you're wanting to pass the k param via the querystring, then you should remove it from the route definition, i.e. [Route("/search")].
I am new to ASP.Net WebAPI and I'm trying to use the NorthWind database to practice.
Now, I have a ProductsController which contains a GetAllProducts and a GetAllProductsById actions.
On the client-side, I have a multiselect dropdown control which is been populated with the categories of products from the CategoriesController class.
I want to populate a second dropdown control (not a multiselect) with the Products from the Categories that was selected in the category dropdown list.
My GetAllProductsById controller looks like this:
public IHttpActionResult GetAllProductsById([FromUri]int[] id)
{
using (var ctx = new NorthwindEntities())
{
<some codes...>
}
return Ok(productList);
}
Calling this service from the client, the URL look like this: http://localhost:1234/api/Products/GetAllProductsById?id=1&id=2&id=3
This is looks good with few parameters but what if the User selects more categories (let's say 30 out of 40 categories)? This means the URL would be so long.
So, I decide to use a POST to do a GET's job by decorating my action with HttpPost:
[HttpPost]
public IHttpActionResult GetAllProductsById([FromBody]int[] id)
This allows me to send the id parameters from the Body of my request.
Now, I am wondering if this style is correct or if someone can point me to a much cleaner way of passing a long list of parameters from a client to my webservice.
Thanks in advance.
NB:
Using Elasticsearch is not an option at the as suggested in the link below:
HTTP GET with request body
I tried using a modal class but it also has the same effect
http://localhost:1234/api/Products/GetAllProductsById?input.id=1&input.id=2
You could do something a bit hacky: use HTTP headers.
First the client should add the ID list as a header to its HTTP request (C# example follows):
var webRequest = System.Net.WebRequest.Create(your_api_url);
webRequest.Headers.Add("X-Hidden-List", serialized_list_of_ids);
And then on the API side:
[HttpGet]
public IHttpActionResult GetAllProductsById()
{
string headerValue = Request.Headers.GetValues("X-Hidden-List").FirstOrDefault();
if (!string.IsNullOrEmpty(headerValue))
{
var results = DeserializeListAndFetch(headerValue);
return Ok(results);
}
else
{
var results = ReturnEverything();
return Ok(results);
// or if you don't want to return everything:
// return BadRequest("Oops!");
}
}
DeserializeListAndFetch(...) and ReturnEverything() would do the actual database querying.
You can have the array of Id in a model class and in the method parameters just accept type of that class. Like
Modal Class
Public class modal
{
Public int[] Ids {get;set;}
}
Your Contoller
public IHttpActionResult GetAllProductsById([FromBody] modal m)
{
//Some logic with m.Ids
}
Your JSON if you are using any UI to consume this API
{"Ids" :[1,2,3,4,5,6]}
Hope this Helps,
I've got problem how to design correctly flow for my controller witch will do some advanced things. I have to have multiple-step adding course in my site. It looks like this:
public class CoursesController : Controller {
[HttpGet]
public ActionResult Create() //1 step - User fill some basic infos and send back forms to Save method
{
return View(model.GetNewInstanceOfCourse());
}
[HttpPost]
public ActionResult Save(NewCourse newCourse) //2 step - Datas are stored in session
{
string Token = Guid.NewGuid().ToString("D");
Session.Add(Token, newCourse);
return RedirectToAction("Subjects", new { Token = Token });
}
[HttpGet]
public ActionResult Subjects(string Token) //2 step - Users fill which Subjects will be on the course, then send forms to Confirm method
{
return View(model.GetAvaliableSubjects(Token/*to place Token in View and let retrieve object from session*/);
}
[HttpPost]
public ActionResult Confirm(Subjects subjects) //3 step - Users filled all required datas and now i want to store complete datas in database
{
//(assume that Session[...] return Dictionaty<string, ... > instead of object
if(!Session["stored-courses-from-first-step"].ContainsKey(subjects.RetrievedFromViewToken)
{
return RedirectToAction("Create");
}
model.AddNewCourse(Session["stored-courses-from-first-step"][subjects.RetrievedFromViewToken], subjects);
return RedirectToAction("Index");
}
}
and it works perfectly... but i have to write adding new subjects for existing course so reuse step 2 in other part of my controller. I have to fill some different datas, then reuse adding subjects for this datas and then reuse function Confirm but instead of inserting some datas i want just update and insert some datas completed from user.
...
public AddNewSubject(int CourseId)
{
...
}
In course preview i have button "Add new subjects", this should bring me to AddNewSubject Method and i don't know what to do next. I can't do in this method something like that:
return RedirectToAction("Save", "Courses", new { newCourse = model.GetExistingCourseAnChangeItToNewCourseInstance(CourseId)})
i don't want to write specialized methods for this due to duplicating most of this code. I think it's possible to reorganize flow in my controller but i doesn't have good idea how to do that. Other problem is that i need to reuse method Confirm, one time it will insert some datas, other time it will update some datas. Maybe you will have some good tips for me.
For existing courses, where you will be passing the course ID, there's nothing stopping you overloading the action method:
[HttpPost]
public ActionResult Save(int CourseId) //2 step - Datas are stored in session
{
// Do whatever you need to do...
}
This way, you do not have to worry about doing anything clever when trying to reuse the step 2 code you posted. You simply have a separate method for dealing with existing courses.
The cleanest solution is remove the real logic from the reusable actions, and put it in private methods.
In the method you decide what to do given some input params or something like that.
So, in your action you end up just calling the helper method. This helper methods can be private in the same controller... or if the amount of logic is large you can create a helper class to host that logic.
Using asp.net MVC 3, I would like to add a query string on every request of Controller's method, using the following code, the query string is not being added to the URL.
Any idea what I am doing wrong or any other alternative approaches?
public ActionResult Index(string uniquestudentreference)
{
return View(eventListVM);
}
public class UserAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
filterContext.ActionParameters["uniquestudentreference"] = Various.GetGivenNameUser();
}
}
If you want the uniquestudentreference parameter to have a value in your controller action, you should simply invoke the controller action with the correct url like:
http://www.someurl.com/<controller>/Index/<uniquestudentreference>
If you want to affect how you pass information through the url, you should look into customizing your route table (located in Global.asax)
You can read more about that here: http://www.asp.net/mvc/tutorials/older-versions/controllers-and-routing/asp-net-mvc-routing-overview-cs
What you want to do here is set the value to the ViewData or TempData of the ControllerContext in the ActionResult, and then reference it in the method. This is a better way to pass it around than querystring, and safer too (avoids user being able to manipulate the value). That or store the value in the Session.
I'm using ASP.MVC and trying to learn...
I have the following controller
// get all authors
public ActionResult Index()
{
var autores = autorRepository.FindAllAutores();
return View("Index", autores);
}
// get authors by type
public ActionResult Index(int id)
{
var autores = autorRepository.FindAllAutoresPorTipo(id);
return View("Index", autores);
}
If I try http://server/Autor/1 I get a 404 error. Why is that?
I even tried to create a specific method ListByType(int id) and the correspondent view, but that does not work too (URL: http://server/Autor/ListByType/1)
Any ideas?
EDIT Oh, the http://server/Autor works just fine. The method without parameters is spitting out my view correctly.
Assuming your class is called AutorController, and assuming you have the default route configuration of
{controller}/{action}/{id}
You should be able to request
/Autor/Index/<anything>
However, you seem to be a bit confused on the action methods. You could combine your action methods like so:
public ActionResult Index(int? id)
{
var autores; // I know this wont compile - but without knowing what type FindAllAutoRes returns, I can't make a specific type for this example
if(id.HasValue)
autores = autorRepository.FindAllAutoresPorTipo(id);
else
autores = autorRepository.FindAllAutores();
return View(autores); // Will automatically select the 'Index' View
}
MVC will select the first valid action method that corresponds to your route data - so if you request /Autor/Index/3, you will get the first action method, but since it has no parameters, the id route data is not bound to anything.