i have a function and i am unclear what i should return from this?
public ActionResult LoadExternalURL()
{
Response.Redirect("http://www.google.com");
// what do i return here ??
}
Instead of calling Response.Redirect it's easier to use the built in RedirectResult ActionResult as follows:-
return Redirect("http://www.google.com");
This will also improve the testability of your code (you don't have to muck around mocking the HTTP context) and instead you can just test the Url property of the returned action result.
Related
I have a MVC method that currently returns an ActionResult - I have had to make some changes and based on the business logic I want to do a response.redirect instead.
So I want to do something like this:
public ActionResult Index(CountryHomePageType currentPage)
{
if (someVar = true)
{
return View();
}
else
{
Response.redirect("www.website.com")
}
}
but I can't becuase Resonse.Redirect is not a ActionResult....
How can I get round this?
If you are redirecting outside of your current mvc application you can use
return Redirect("<your external url>"); // like "https://www.google.com"
if you want to redirecto back you your homepage you can use
return RedirectToAction("Index", "Home");
assuming you are using the default mvc setup
You might want to also look at ActionFilters if you are making this check in multiple places.
I have a method that looks as follows:
[Authorize]
public ActionResult Create(int? birdRowId, Entities.BirdSighting sighting)
{
...
...
}
I want to call the above method from another method in the same controller as follows:
[Authorize]
[HttpPost]
public ActionResult Create(Entities.BirdSighting birdSighting, FormCollection collection)
{
...
...
return RedirectToAction("Create", new {birdRowId = 10, sighting = birdSighting});
}
The RedirectToAction method calls the method correctly. And, the first parameter of the method being called (birdRowId) does equal 10. However, the second parameter, sighting, is always null, even though I'm passing an instantiated object with values. What am I doing wrong?
Remember, HTTP is stateless !
RedirectToAction method returns a 302 response to the client browser and thus the browser will make a new GET request to the specified URL.
If you are trying to follow the PRG pattern, I think you should not try to pass complex objects. You should only pass the ID of the resource so that the GET action can build the resource( the model) again using that ID.
return RedirectToAction("Created", "YourControllerName", new { #id=10} );
and in the Created action, read the id and build the object there.
public ActionResult Created(int id)
{
BirdSighting sighting=GetSightingFromIDFromSomeWhere(id);
// to do :Return something back here (View /JSON etc..)
}
If you really want to pass some data across (Stateless) HTTP Requests, you may use some temporary storage mechanism like TempData
Set your object to TempData in your HttpPost action method.
[HttpPost]
public ActionResult Create(BirdSighting birdSighting, FormCollection collection)
{
// do something useful here
TempData["BirdSighting"] =birdSighting;
return RedirectToAction("Created", "YourControllerName");
}
And in your GET action method,
public ActionResult Created()
{
var model=TempData["BirdSighting"] as BirdSighting;
if(model!=null)
{
//return something
}
return View("NotFound");
}
TempData uses Session object behind the scene to store the data. But once the data is read, the data is terminated.
I'm not sure if this is the correct way to go about the problem I need to solve... however in an OnActionExecuting action filter that I have created, I set a cookie with various values. One of these values is used to determine whether the user is visiting the website for the very first time. If they are a new visitor then I set the ViewBag with some data so that I can display this within my view.
The problem I have is that in some of my controller actions I perform a RedirectToAction. The result is OnActionExecuting is fired twice, once for the original action and then a second time when it fires the new action.
<HttpGet()>
Function Index(ByVal PageID As String) As ActionResult
Dim wo As WebPage = Nothing
Try
wp = WebPages.GetWebPage(PageID)
Catch sqlex As SqlException
Throw
Catch ex As Exception
Return RedirectToAction("Index", New With {.PageID = "Home"})
End If
End Try
Return View("WebPage", wp)
End Function
This is a typical example. I have a data driven website that gets a webpage from the database based on the PageID specified. If the page cannot be found in the database I redirect the user to the home page.
Is it possible to prevent the double firing in anyway or is there a better way to set a cookie? The action filter is used on multiple controllers.
Had the same issue. Resolved by overriding property AllowMultiple:
public override bool AllowMultiple { get { return false; } }
public override void OnActionExecuting(HttpActionContext actionContext)
{
//your logic here
base.OnActionExecuting(actionContext);
}
You can save some flag value into TempData collection of controller on first executing and if this value presented, skip filter logic:
if (filterContext.Controller.TempData["MyActionFilterAttribute_OnActionExecuting"] == null)
{
filterContext.Controller.TempData["MyActionFilterAttribute_OnActionExecuting"] = true;
}
You could return the actual action instead of redirecting to the new action. That way, you dont cause an http-request, thereby not triggering the onactionexecuting (i believe)
Old question, but I just dealt with this so I thought I'd throw in my answer. After some investigating I disovered this was only happening on endpoints that returned a view (i.e. return View()). The only endpoints that had multiple OnActionExecuting fired were HTML views that were composed of partial views (i.e. return PartialView(...)), so a single request was "executing" multiple times.
I was applying my ActionFilterAttribute globally to all endpoints, which was working correctly on all other endpoints except for the view endpoints I just described. The solution was to create an additional attribute applied conditionally to the partial view endpoints.
// Used specifically to ignore the GlobalFilterAttribute filter on an endpoint
public class IgnoreGlobalFilterAttribute : Attribute { }
public class GlobalFilterAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
// Does not apply to endpoints decorated with Ignore attribute
if (!filterContext.ActionDescriptor.GetCustomAttributes(typeof(IgnoreGlobalFilterAttribute), false).Any())
{
// ... attribute logic here
}
}
}
And then on my partial view endpoints
[HttpGet]
[AllowAnonymous]
[IgnoreGlobalFilter] //HERE this keeps the attribute from firing again
public ActionResult GetPartialView()
{
// partial view logic
return PartialView();
}
I have data that will either be consumed by a human or a web service. The REST url is:
http://host.com/movies/detail/1
http://host.com/movies/detail/The Shawshank Redemption (1994)
What convention should I follow to conditionally return JSON or HTML? Should I add a parameter such as "?json" or should I look at the client headers,.. some variation of both?
If I do a variation of both, if a conflict is found which takes precedent?
Check whether the Request is Ajax. You may use the Request.IsAjaxRequest() method which returns true/false.
public ActionResult details(string id)
{
var movieViewModel=movieService.GetMovieDetails(id);
If(Request.IsAjaxRequest())
{
// return Json now
return Json(movieViewModel,JsonRequestBehavior.AllowGet);
}
// Not an ajax request, Let's return Normal View (HTML)
return View(movieViewModel);
}
UNIT TESTING ASPECT : Request.IsAjaxRequest() is not unit test friendly! So if you are worried about unit tests, You can write your IsAjaxRequest property and put in your basecontroller class and use it.
public class BaseController : Controller
{
protected bool IsAjaxRequest()
{
//Using this method instead of Request.IsAjaxRequest() because
//IsAjaxRequest is static and not mockable ! (not unit test friendly)
var isAjax = Request.Headers["X-Requested-With"];
if (isAjax != null && isAjax.ToUpper() == "XMLHTTPREQUEST")
return true;
return false;
}
}
Now inherit your controller from this BaseController.
public class HomeController : BaseController
{
public ActionResult details(string id)
{
var movieViewModel=movieService.GetMovieDetails(id);
If(IsAjaxRequest)
{
// return Json now
return Json(movieViewModel,JsonRequestBehavior.AllowGet);
}
// Not an ajax request, Let's return Normal View (HTML)
return View(movieViewModel);
}
}
You could also use:
[HttpGet]
public ActionResult() {
// Return HTML
}
[HttpPost]
public ActionResult() {
// Assuming Ajax is of the type post
}
Just another solution if all your Ajax is using post.
I prefer using a parameter explicit in the URL because that way building REST petitions is easy for developers, self explanatory and with no surprises (do you have to guess default format? or see "difficult" to see HTTP headers). You decide:
if you have many options for formats you can use format=json
you can go with json parameter, but it is not pretty because you have to pair it with a value json=true, json=1. Besides you can set json=1&xml=1&html=1, harder to handle.
the twitter way is to emulate an extension such as call.json or call.xml (e.g. https://dev.twitter.com/docs/api/1.1/get/statuses/user_timeline)
I recommend don't tie together a kind of petition and a format. Let your API clients decide, ajax-json is commonly used, but not all develepers use it that way. Maybe I am writing a terminal application with no ajax, maybe I want to do a wget to your API and still get json.
I have an action like shown below. In GetAvailableBookList, I get the list and if there is not any available book redirect to a message page. But in action part code continues to execute and gets an exception and I find myself in error page.
I don't want to use return RedirectToAction or something like that because there are a lot of places where we use this redirect logic in our application.
public ActionResult ActionName()
{
List<BookType> bookList = GetAvailableBookList();
// some code
return View("RelatedView");
}
private List<BookType> GetAvailableBookList()
{
....
list = GetList();
if(list.Count == 0)
{
System.Web.HttpContext.Current.Response.Redirect(messagePageUrl, true);
}
else return list;
}
Unfortunately, Response.Redirect() isn't really friendly with ASP.NET MVC. My rule of thumb is if it comes from HttpContext I don't want to touch it in the controller (of course there are many exceptions to that rule) -- especially since it improves testability.
My suggestion is to use RedirectToAction, but since you don't want to repeat code you can do it in such a way that you don't have to repeat code (although in this case I don't see a problem with repeating code).
public ActionResult LoadBookListAndContinue(
Func<List<BookType>, ActionResult> continuation)
{
var list = LoadBooklist();
if(list.Any())
{
return action(continuation);
}
return new RedirectResult(messagePageUrl);
}
// in your controller
public ActionResult ActionName()
{
return LoadBookListAndContinue(
list => {
// some code
return View("RelatedView");
});
}
Is it pretty? No, but it works better than the Redirect exception.
Use
return RedirectToAction("NoListAvailable");
if you have a specific action you would like to execute. The NoListAvailable action can return a view indicating the problem.
Alternatively, you could return the view directly
return View("NoListAvailable");
The exception you are getting is probably ThreadAbortException and this is something you cannot avoid unless you allow the thread to continue (2nd argument in Response.Redirect).
On a side note your current solution is generally flawed. You should use RedirectToAction in each action when your method returns an empty list.
Throwing a specific exception and redirect where you catch it may be solution
Try to write
System.Web.HttpContext.Current.Response.Redirect(messagePageUrl, false);