I have a page routed like /Comments/Search/3 where i search and display all the comments of the thread "3".
I'm adding a sort function (by date, author etc). What is the best way to handle it? /Comments/Search/3/Sort/Author or /Comments/Search/3?sort=author ?
How do I automatically handle the querystring sort=author as a parameter in MVC?
Thanks
I prefer: /Comments/Search/3?sort=author. The querystring is a good place to pass in programmatic parameters, especially if the parameter (like in this case) is not important for SEO purposes. If the parameter had some semantic meaning as a search term, the first URL would be better.
In a controller method you can use something like this:
public ActionResult Search(int id, string sort)
ASP.NET MVC will automatically wire up querystring values to the parameters of your method.
Use the following route
routes.MapRoute(
"Default", // Route name
"{controller}/{action}/{id}", // URL with parameters
new { controller = "Comments", action = "Search", id = "" } // Parameter defaults
);
/Comments/Search/3?sort=author will call Search(3, "author")
/Comments/Search/3 will call Search(3, null)
Keep in mind that id is mandatory so this url will fail:
/Comments/Search
ASP.NET MVC will handle that automatically in the query string case. You just add a string sort parameter to your action.
Which is better? Personally, I use the path to control the contents being displayed and querystring to control the presentation (how it's displayed, formatted, ...). So, for sorting, I'd go with the querystring method. But I don't think there's a technical disadvantage in either approach.
Your best bet is to add a routing rule to handle it. There's a handy article on it here:
http://aspalliance.com/1525_ASPNET_MVC_Framework_Part_2_URL_Routing.2
Then your URL would read /Comments/Search/3/Sort/Author
Related
I have an actionresult with two parameter:
public ActionResult Index(int a,string b)
{
//some code
return View(b);
}
it creates this url automatically:
mysite.com/a=1&b=http://site.com/b=1
I just need to show first parameter "a" in my url:
mysite.com/a=1
I use the default route of MVC that creates in global.ascx:
routes.MapRoute(
"Default", // Route name
"{controller}/{action}/{id}", // URL with parameters
new { controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults
);
what should i do?
Thanks...
If you are seeing the "b" parameter bleed through from the current request, you can set the "b" parameter explicitly to empty string to avoid this behavior:
#Html.ActionLink("Home", "Index", "Home", new { a = 1, b = "" }, null)
I reported this "feature" as a bug, but the developers at Microsoft seem to think this behavior is supposed to make your URLs easier to configure, and they don't intend to fix it.
What you're seeing here is a feature of routing where "ambient" values (i.e. values that were detected in the incoming request's URL) are used to simplify (sometimes...) the generation of routes to other pages.
You can check our my answer (under the name "Eilon") in this StackOverflow post, where I explain the behavior in a bit more detail:
How Can I Stop ASP.Net MVC Html.ActionLink From Using Existing Route Values?
Ultimately if you want the most control over what gets generated for a URL there are a few options to consider:
Use named routes to ensure that only the route you want will get used to generate the URL (this is often a good practice, though it won't help in this particular scenario)
Specify all route parameters explicitly - even the values that you want to be empty. That is one way to solve this particular problem.
Instead of using Routing to generate the URLs, you can use Razor's ~/ syntax or call Url.Content("~/someurl") to ensure that no extra (or unexpected) processing will happen to the URL you're trying to generate.
Thanks,
Eilon
This is a more specific version of another of my questions: Restful MVC Web Api Inheritance, I hope an answer to this will help me answer that.
Im using ASP.NET web api,
I want to be able to route something like this: [{object}/{id}]/{controller}/{id}.
so i want an array of objects with optional /{id} ending with the 'api endpoint'.
I want to be able to route these:
/houses
/houses/3
suburbs/3/houses
council/5/suburbs/houses
city/8/council/suburbs/houses
ETC
TO
get(List<restRoute>parents, int id){
...
}
restRoute would be an object with a string for the object and an optional int (or guid etc) for the id
Does anyone know where i can start?
I don't want to route every single one individually.
I had also such problems with routing from the box in ASP.NET MVC. Its good way to be used as common routing, but is not so flexible for custom routs.
In WCF Web Api (ASP.NET web api in CTP version) was used attribute based routing.
I think its more flexible, but as negative point - each method should have routing attribute.
Take a look at this blog post:
http://www.strathweb.com/2012/05/attribute-based-routing-in-asp-net-web-api/
It describes how to implement attribute based routing using ASP.NET Web Api. Because such approach is more flexible for routes you can map to methods, it can be helpful for you.
You could use the {*anything} Variable Segmented URL pattern in your route and handle the splitting up and figuring out of what part of the url corresponds to what bit of data in your method:
Global.asax:
routes.MapRoute(
"Special", // name
"{*allthethings}", // parameters
new { controller = "Special", action = "Sauce" } // defaults
);
SpecialController:
public ActionResult Sauce()
{
string data = RouteData.Values["allthethings"].ToString();
string[] items = data.Split('/');
foreach (string item in items)
{
// do whatever you need to figure out which is what!
}
return View();
}
If you wanted to be a bit cleverer about it you could create your own custom RouteHandler to do the splitting. Something like David Ebb's PK routehandler would probably do the trick, with some customisation to fit your requirements in the processing of the route. You could use this to split up the "allthethings" parameter and turn it into your List<RestRoute> format before passing the request on to the Controller
I have a simple create action to receive post form data, save to db and redirect to list view.
The problem is, after redirecttoaction result excutes, the url on my browser lost the action section. Which it should be "http://{hotsname}/Product/List" but comes out as "http://{hotsname}/Product/".
Below is my code:
[HttpPost]
public ActionResult Create(VEmployee model, FormCollection fc)
{
var facility = FacilityFactory.GetEmployeeFacility();
var avatar = Request.Files["Avatar"].InputStream;
var newModel = facility.Save(model, avatar);
return RedirectToAction("List");
}
The page can correctly render list view content, but since some links in this view page use relative url, the functions are interrupted. I am now using return Redirect("/Employee/List") to force the url. But I just wonder why the action name is missing. I use MVC3 and .Net framwork 4.
I am new to ASP.Net MVC, thanks for help.
Your route table definitely says that "List" action is default, so when you redirect to it as RedirectToAction("List") - routing ommits the action because it is default.
Now if you remove the default value from your routes - RedirectToAction will produce a correct (for your case) Url, but you'll have to double check elsewhere that you are not relying on List being a default action.
Well, Chris,
If you get the right content on http://{hotsname}/Product/ then it seems that routing make that URL point to List either indirectly (using pattern like {controller}/{action}) and something wrong happens when resolving URL from route or {action} parameter is just set wth default value List. Both URLs can point to the same action but the routing engine somehow takes the route without explicit action name.
You should check:
Order in which you define your routes
How many routes can possibly lead to EmployeeController.List()
Which one of those routes has the most priority
Default values for your routes
Just make the route with explicit values: employee/list to point to your List action and make sure that is the route to select when generating links (it should be most specific route if possible).
It would be nice if you provide your routes mappings here.
but since some links in this view
page use relative url, the functions
are interrupted.
Why do you make it that way? Why not generate all the links through routing engine?
When using the overload RedirectToAction("Action") you need to be specifying an action that is in the same controller. Since you are calling an action in a different controller, you need to specify the action with the alternate overload e.g. RedirectToAction("List", "Employee").
Due to factors outside my control, I need to handle urls like this:
http://www.bob.com/dosomething.asp?val=42
I would like to route them to a specific controller/action with the val already parsed and bound (i.e. an argument to the action).
Ideally my action would look like this:
ActionResult BackwardCompatibleAction(int val)
I found this question: ASP.Net MVC routing legacy URLs passing querystring Ids to controller actions but the redirects are not acceptable.
I have tried routes that parse the query string portion but any route with a question mark is invalid.
I have been able to route the request with this:
routes.MapRoute(
"dosomething.asp Backward compatibility",
"{dosomething}.asp",
new { controller = "MyController", action = "BackwardCompatibleAction"}
);
However, from there the only way to get to the value of val=? is via Request.QueryString. While I could parse the query string inside the controller it would make testing the action more difficult and I would prefer not to have that dependency.
I feel like there is something I can do with the routing, but I don't know what it is. Any help would be very appreciated.
The parameter val within your BackwardCompatibleAction method should be automatically populated with the query string value. Routes are not meant to deal with query strings. The solution you listed in your question looks right to me. Have you tried it to see what happens?
This would also work for your route. Since you are specifying both the controller and the action, you don't need the curly brace parameter.
routes.MapRoute(
"dosomething.asp Backward compatibility",
"dosomething.asp",
new { controller = "MyController", action = "BackwardCompatibleAction"}
);
If you need to parametrize the action name, then something like this should work:
routes.MapRoute(
"dosomething.asp Backward compatibility",
"{action}.asp",
new { controller = "MyController" }
);
That would give you a more generic route that could match multiple different .asp page urls into Action methods.
http://www.bob.com/dosomething.asp?val=42
would route to MyController.dosomething(int val)
and http://www.bob.com/dosomethingelse.asp?val=42
would route to MyController.dosomethingelse(int val)
What's the best way to handle a visitor constructing their own URL and replacing what we expect to be an ID with anything they like?
For example:
ASP.Net MVC - handling bad URL parameters
But the user could just as easily replace the URL with:
https://stackoverflow.com/questions/foo
I've thought of making every Controller Function parameter a String, and using Integer.TryParse() on them - if that passes then I have an ID and can continue, otherwise I can redirect the user to an Unknown / not-found or index View.
Stack Overflow handles it nicely, and I'd like to too - how do you do it, or what would you suggest?
Here's an example of a route like yours, with a constraint on the number:
routes.MapRoute(
"Question",
"questions/{questionID}",
new { controller = "StackOverflow", action = "Question" },
new { questionID = #"\d+" } //Regex constraint specifying that it must be a number.
);
Here we set the questionID to have at least one number. This will also block out any urls containing anything but an integer, and also prevents the need for a nullable int.
Note: This does not take into account numbers that larger than the range of Int32 (-2147483647 - +2147483647). I leave this as an exercise to the user to resolve. :)
If the user enters the url "questions/foo", they will not hit the Question action, and fall through it, because it fails the parameter constraint. You can handle it further down in a catchall/default route if you want:
routes.MapRoute(
"Catchall",
"{*catchall}", // This is a wildcard routes
new { controller = "Home", action = "Lost" }
);
This will send the user to the Lost action in the Home controller. More information on the wildcard can be found here.
NB: The Catchall should reside as the LAST route. Placing it further up the chain will mean that this will handle all others below it, given the lazy nature of routes in ASP.NET MVC.
Here is some useful infromation that might help.
If you have a action method
public ActionResult Edit(int? id)
{}
then if someone types in
/Home/Edit/23
the parameter id will be 23.
however if someone types in
/Home/Edit/Junk
then id will be null which is pretty cool. I thought it would throw a cast error or something. It means that if id is not a null value then it is a valid integer and can be passed to your services etc. for db interaction.
Hope this provides you with some info that I have found whilst testing.
In ASP.NET MVC, you can define a filter implementing IActionFilter interface. You will be able to decorate your action with this attribute so that it will be executed on, before or after your action.
In your case, you will define it to be executed "before" your action. So that, you will be able to cancel it if there is an error in the passed parameters. The key benefit here that you only write the code which checking the passed paramaters once (i.e you define it in your filter) and use it wherever you want in your controller actions.
Read more about MVC filters here: http://haacked.com/archive/2008/08/14/aspnetmvc-filters.aspx
You can specify constraints as regular expressions or define custom constraints. Have a look at this blog post for more information:
http://weblogs.asp.net/stephenwalther/archive/2008/08/06/asp-net-mvc-tip-30-create-custom-route-constraints.aspx
You will still need to deal with the situation where id 43243 doesn't map to anything which could be dealt with as an IActionFilter or in your controller directly.
The problem with that approach is that they still might pass an integer which doesn't map to a page. Just return a 404 if they do that, just as you would with "foo". It's not something to worry about unless you have clear security implications.