UrlHelper.Action includes undesired additional parameters - c#

I have a method in the controller ApplicationsController, in which I need to get the base URL for an action method:
public ActionResult MyAction(string id)
{
var url = Url.Action("MyAction", "Applications");
...
}
The problem is that this includes the string id from the current route data, when I need the URL without (the URL is used to fetch content from a CMS on a URL-based lookup).
I have tried passing null and new { } as the routeValues parameter to no avail.
The matching route is as follows (above all other routes):
routes.MapLowercaseRoute(
name: "Applications",
url: "applications/{action}/{id}",
defaults: new { controller = "Applications",
action = "Index", id = UrlParameter.Optional });
I've seen a couple of other questions touch on this but none of them seem to have a viable solution. At present, I am resorting to hardcoding the path in the controller; however, I'd like to be able to abstract this into an action filter, so I need to be able to generate the URL.
Is there a clean/conventional way to prevent this behaviour?

Ok, I see the problem. It's something called "Segment variable reuse". When generating the routes for outbound URLs, and trying to find values for each of the segment variables in a route’s URL pattern, the routing system will look at the values from the current request. This is a behavior that confuses many programmers and can lead to a lengthy debugging session. The routing system is keen to make a match against a route, to the extent that it will reuse segment variable values from the incoming URL. So I think you have to override the value like Julien suggested :
var url = Url.Action("MyAction", "Applications", new { id = "" })

Ended up getting around this with a different approach. The only way I could come up with to prevent arbitrarily-named route values from being inserted into the generated URL was to temporarily remove them from RouteData when calling Url.Action. I've written a couple of extension methods to facilitate this:
public static string NonContextualAction(this UrlHelper helper, string action)
{
return helper.NonContextualAction(action,
helper.RequestContext.RouteData.Values["controller"].ToString());
}
public static string NonContextualAction(this UrlHelper helper, string action,
string controller)
{
var routeValues = helper.RequestContext.RouteData.Values;
var routeValueKeys = routeValues.Keys.Where(o => o != "controller"
&& o != "action").ToList();
// Temporarily remove routevalues
var oldRouteValues = new Dictionary<string, object>();
foreach (var key in routeValueKeys)
{
oldRouteValues[key] = routeValues[key];
routeValues.Remove(key);
}
// Generate URL
string url = helper.Action(routeValues["Action"].ToString(),
routeValues["Controller"].ToString());
// Reinsert routevalues
foreach (var kvp in oldRouteValues)
{
routeValues.Add(kvp.Key, kvp.Value);
}
return url;
}
This allows me to do this in an action filter where I won't necessarily know what the parameter names for the action are (and therefore can't just pass an anonymous object as in the other answers).
Still very much interested to know if someone has a more elegant solution, however.

Use a null or empty value for id to prevent Url.Action from using the current one:
var url = Url.Action("MyAction", "Applications", new { id = "" })

I was not entirely comfortable with the altering, transient or otherwise, of the RouterData in #AntP's otherwise fine solution. Since my code for creating the links was already centralized, I borrowed #Tomasz Jaskuλa and #AntP to augment the ExpandoObject, I was already using.
IDictionary<string,object> p = new ExpandoObject();
// Add the values I want in the route
foreach (var (key, value) in linkAttribute.ParamMap)
{
var v = GetPropertyValue(origin, value);
p.Add(key, v);
}
// Ideas borrowed from https://stackoverflow.com/questions/20349681/urlhelper-action-includes-undesired-additional-parameters
// Null out values that I don't want, but are already in the RouteData
foreach (var key in _urlHelper.ActionContext.RouteData.Values.Keys)
{
if (p.ContainsKey(key))
continue;
p.Add(key, null);
}
var href = _urlHelper.Action("Get", linkAttribute.HRefControllerName, p);

Related

Specify returnURL In QueryString

This is probably a simple question but I am struggling with returnurl in a querystring. I know how to call the returnurl in a querystring into a Response.Redirect but I am not sure how to set the returnurl to a certain url. Can someone give me a example of how to do this?
I have a suggestion for you, I'm sure how much it is apt for your situation.
Let me define a Static Dictionary<string,string> to save some key and corresponding URLs. Since it is statically defined you can access it from all other pages, this variable will get application scope. ie.,
public static Dictionary<string, string> URLDictonary = new Dictionary<string, string>()
{
{"google","http://google.com/"},
{"dotnet","http://www.dotnetperls.com/"},
{"querystring","http://www.dotnetperls.com/querystring"}
};
So that you can attach the key name with the URL as query string. It may look like the following:
Response.Redirect("~/Somepage.aspx?returnURL=google");
// Which means you are passing the key as query string
Now you can get this key in sample page and redirect to the specific page based on the key as follows:
string returnURL = Request.QueryString["returnURL"];
if (returnURL != null)
{
Response.Redirect(URLDictonary[returnURL]);
}
Since we are passing google it will redirect to the corresponding value ie. "http://google.com/".
Note : You can create similar Dictionary with your own keys and Urls. If it is defined in a different class then use class_name.DictonaryName[querystring_value]
You could do it in the following:
var url = Request.Url.ToString();
var uri = String.Format("http://example.com?page={0}", url);
Response.Redirect(uri);
The code is pretty straight forward.

RouteTester issues with optional parameter in routing

I have a MVC4 WebApi project with routing that is working correctly with an optional "id" parameter in the route:
routes.Add(new ApiRouteInfo
{
Name = this.AreaName.ToLower() + "_readingsplans",
RouteTemplate = baseUrl + "/plans/readingalerts/{id}",
Defaults = new
{
area = this.AreaName.ToLower(),
controller = "ReadingAlerts",
id = RouteParameter.Optional
}
});
When making an actual request the routing works to hit either the GetAll or Get method in the controller methods:
public HttpResponseMessage GetAll(BaseQueryFilter filter)
public HttpResponseMessage Get(int id)
But in the unit test, the RouteTester object always hits the Get method, not the GetAll.
Works:
Assert.AreEqual(ReflectionHelper.GetMethodName((ReadingAlertsController p) => p.Get(It.IsAny<int>())), routeTester.GetActionName());
Fails:
Assert.AreEqual(ReflectionHelper.GetMethodName((ReadingAlertsController p) => p.GetAll(null)), routeTester.GetActionName());
I've tried passing in an actual filter object instead of null but that doesn't change the outcome at all.
I know I can fix it by creating two different routes, but I'm a bit reluctant since the current routing does work for everything except the unit test.
Any suggestions?
Did you look at this? It explains a lot about unit testing web api and it may be useful to you.
I found a stackoverflow thread which describes how to test out the route. I am using something similar that I found on the net, but I am willing to try it.
Here is another article with a similar implementation. This is what I am using and having a similar issue with.
--Updated--
I believe I found the fix for the issue. Using the article mentioned above, I replaced the 'GetActionDescriptor()' function with the following:
private HttpActionDescriptor GetActionDescriptor()
{
if (controllerContext.ControllerDescriptor == null)
GetControllerType();
var actionSelector = new ApiControllerActionSelector();
var results = actionSelector.GetActionMapping(controllerContext.ControllerDescriptor);
try
{
return actionSelector.SelectAction(controllerContext);
}
catch
{
var subActions = results[request.RequestUri.Segments.Last()];
var action = subActions.FirstOrDefault(a => a.SupportedHttpMethods.First(m => m.Method == request.Method.Method) != null);
return action;
}
}

Get site url on mvc

I want to write a little helper function that returns the site url.
Coming from PHP and Codeigniter, I'm very upset that I can't get it to work the way I want.
Here's what I'm trying:
#{
var urlHelper = new UrlHelper(Html.ViewContext.RequestContext);
var baseurl = urlHelper.Content("~");
}
<script>
function base_url(url) {
url = url || "";
return '#baseurl' + url;
}
</script>
I want to return the base url of my application, so I can make ajax calls without worrying about paths. Here's how I intend to use it:
// Development
base_url(); // http://localhost:50024
// Production
base_url("Custom/Path"); // http://site.com/Custom/Path
How can I do something like that?
EDIT
I want absolute paths because I have abstracted js objects that makes my ajax calls.
So suppose I have:
function MyController() {
// ... js code
return $resource('../MyController/:id');
}
// then
var my_ctrl = MyController();
my_ctrl.id = 1;
my_ctrl.get(); // GET: ../MyController/1
This works when my route is http://localhost:8080/MyController/Edit but will fail when is http://localhost:8080/MyController .
I managed to do it like this:
#{
var url = Request.Url;
var baseurl = url.GetLeftPart(UriPartial.Authority);
}
Thank you all!
Are you aware of #Url.Action("actionname") and #Url.RouteUrl("routename") ?
Both of these should do what you're describing.
Instead of manually creating your URL's, you can use #Url.Action() to construct your URLs.
<p>#Url.Action("Index", "Home")</p>
/Home/Index
<p>#Url.Action("Edit", "Person", new { id = 1 })</p>
/Person/Edit/1
<p>#Url.Action("Search", "Book", new { title = "Gone With The Wind" })</p>
/Book/Search?title="Gone+With+The+Wind"
Now the absolute best reason to go with this option is that #Url.Action automatically applies any vanity URL routes you have defined in your Global.asax file. DRY as the sub-saharan desert! :)
In your case, your can create a 'custom path' in two ways.
Option A)
<p>#Url.Action("Path", "Custom")</p>
/Custom/Path
Option B)
You can create a route using the Global.asax file. So your controller/action combo can be anything you want, and you can create a custom vanity route url - regardless of the controller/action combo.

ASP.NET MVC: Redirect from query string params to a canonical url

In my Asp.Net Mvc project I'd like to have a good looking urls, e.g. mysite.com/Page2, and I want to redirect from my old style urls (such as mysite.com?page=2) with 301 state so that there won't be two urls with identical content. Is there a way to do it?
As far as I know Asp.Net binding framework doesn't make difference between query string and curly brace params
I am not sure, I got your question right. It seems, your current setup relies on those GET parameters (like mysite.com?page=2). If you dont want to change this, you will have to use those parameters further. There would be no problem in doing so, though. Your users do not have to use or see them. In order to publish 'new style URLs' only, you may setup a URL redirect in your web server. That would change new style URLs to old style URLs.
The problem is the 301. If the user requests an old style URL, it would be accepted by the webserver as well. Refusing the request with a 301 error seems hard to achieve for me.
In order to get around this, I guess you will have to change your parameter scheme. You site may still rely on GET parameters - but they get a new name. Lets say, your comments are delivered propery for the following (internal) URL in the old scheme:
/Article/1022/Ms-Sharepoint-Setup-Manual?newpage=2
Note the new parameter name. In your root page (or master page, if you are using those), you may handle the redirect permanent (301) manually. Therefore, incoming 'old style requests' are distinguishable by using old parameter names. This could be used to manually assemble the 301 in the response in ASP code.
Personally, I would sugesst, to give up the 301 idea and just use URL redirection.
Well, as far as I can see performing such redirection in ASP.NET MVC might be tricky. This is how I did it:
global.asax:
routes.Add(new QueryStringRoute());
routes.MapRoute(null, "Article/{id}/{name}",
new { controller = "Article", action = "View", page = 1 },
new { page = #"\d+" }
);
routes.MapRoute(null, "Article/{id}/{name}/Page{page}",
new { controller = "Article", action = "View" },
new { page = #"\d+" }
);
QueryStringRoute.cs:
public class QueryStringRoute : RouteBase
{
private static string[] queryStringUrls = new string[]
{
#"~/Article/\d{1,6}/.*?page=\d{1,3}"
};
public override RouteData GetRouteData(HttpContextBase httpContext)
{
string url = httpContext.Request.AppRelativeCurrentExecutionFilePath;
foreach (string queryStringUrl in queryStringUrls)
{
Regex regex = new Regex(queryStringUrl);
if (regex.IsMatch(url))
{
long id = 0; /* Parse the value from regex match */
int page = 0; /* Parse the value from regex match */
string name = ""; /* Parse the value from regex match */
RouteData rd = new RouteData(this, new MvcRouteHandler());
rd.Values.Add("controller", "QueryStringUrl");
rd.Values.Add("action", "Redirect");
rd.Values.Add("id", id);
rd.Values.Add("page", page);
rd.Values.Add("name", name);
rd.Values.Add("controllerToRedirect", "Article");
rd.Values.Add("actionToRedirect", "View");
return rd;
}
}
return null;
}
public override VirtualPathData GetVirtualPath(RequestContext requestContext, RouteValueDictionary values)
{
return null;
}
}
QueryStringUrlController.cs:
public class QueryStringUrlController : Controller
{
public RedirectToRouteResult Redirect(long id, int page, string name,
string controllerToRedirect, string actionToRedirect)
{
return RedirectToActionPermanent(actionToRedirect, controllerToRedirect, new { id = id, page = page, name = name });
}
}
Assuming you have such routing as in my global.asax file (listed above) you can create a custom Route class that will handle incoming requests and map them on a special redirection controller which will then redirect them to appropriate urls with 301 state. Then you must add this route to global.asax before your "Article" routes
If you're using IIS 7, the URL Rewrite Module should work for your scenario.

How can I get controller type and action info from a url or from route data?

How can I get the controller action (method) and controller type that will be called, given the System.Web.Routing.RouteData?
My scenario is this - I want to be able to do perform certain actions (or not) in the OnActionExecuting method for an action.
However, I will often want to know not the current action, but the "root" action being called; by this I mean I may have a view called "Login", which is my login page. This view may include
another partial view "LeftNav". When OnActionExecuting is called for LeftNav, I want to be able to determine that it is really being called for the "root" aciton of Login.
I realise that by calling RouteTable.Routes.GetRouteData(actionExecutingContext.HttpContext), I can get the route for the "root" request, but how to turn this into
method and type info?
The only solution I have so far, is something like:
var routeData = RouteTable.Routes.GetRouteData(actionExecutingContext.HttpContext)
var routeController = (string)routeData.Values["controller"];
var routeAction = (string)routeData.Values["action"];
The problem with this is that "routeController" is the controller name with the "Controller" suffix removed, and is not fully qualified; ie it is "Login", rather than "MyCode.Website.LoginController".
I would far rather get an actual Type and MethodInfo if possible, or at least a fully qualified type name.
Any thoughts, or alternative approaches?
[EDIT - this is ASP.Net MVC 1.0]
protected override void OnActionExecuting(ActionExecutingContext filterContext)
{
var type1 = filterContext.Controller.GetType();
var type2 = filterContext.ActionDescriptor
.ControllerDescriptor.ControllerType;
}
OK, sorry, I missed the "root" part.
Then, another way, you can save controller type to thread storage. Pseudocode:
protected override void OnActionExecuting(ActionExecutingContext filterContext)
{
if (!Thread.LocalStorage.Contains("root_controller"))
Thread.LocalStorage["root_controller"] =
filterContext.ActionDescriptor
.ControllerDescriptor.ControllerType;
}
Just an idea. I'm sure thread local storage is available in C#. The key idea here is that you save it only for first request, thus it's always root controller.
Here is the solution I compiled from various sources. The url variable should contain the URL of the action:
url = "YOUR URL";
// Original path is stored and will be rewritten in the end
var httpContext = new HttpContextWrapper(HttpContext.Current);
string originalPath = httpContext.Request.Path;
try
{
// Fake a request to the supplied URL into the routing system
httpContext.RewritePath(url);
RouteData urlRouteData = RouteTable.Routes.GetRouteData(httpContext);
// If the route data was not found (e.g url leads to another site) then authorization is denied.
// If you want to have a navigation to a different site, don't use AuthorizationMenu
if(urlRouteData != null)
{
string controllerName = urlRouteData.Values["controller"].ToString();
string actionName = urlRouteData.Values["action"].ToString();
// Get an instance of the controller that would handle this route
var requestContext = new RequestContext(httpContext, urlRouteData);
var controllerFactory = ControllerBuilder.Current.GetControllerFactory();
var controller = (ControllerBase) controllerFactory.CreateController(requestContext, controllerName);
// Find the action descriptor
var controllerContext = new ControllerContext(httpContext, new RouteData(), controller);
var controllerDescriptor = new ReflectedControllerDescriptor(controller.GetType());
var actionDescriptor = controllerDescriptor.FindAction(controllerContext, actionName);
}
}
finally
{
// Reset our request path.
httpContext.RewritePath(originalPath);
}
public Type ControllerType(string controllerName)
{
var fullName = controllerName + "Controller";
var assemblyName = Assembly.GetExecutingAssembly().FullName;
return Activator.CreateInstance(assemblyName, fullTypeName).GetType();
}
public MethodInfo ActionMethodInfo(string actionName, Type controllerType)
{
return controllerType.GetMethod(actionName);
}
Are you thinking of an implementation similar to this? Some Try/Catches required!
MvcSiteMapProvider does this. Here is the code for this particular thing.
Here is the code

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