ASP.NET Mvc - nullable parameters and comma as separator - asp.net-mvc-2

How should I define route in my global.asax to be able use nullable parameters and coma as separator?
I'm trying to implement routing rule for my search users page like
"{Controller}/{Action},{name},{page},{status}"
Full entry from the Global.asax:
routes.MapRoute(
"Search",
"{controller}/{action},{name},{page},{status}",
new { controller = "User", action = "Find",
name = UrlParameter.Optional,
page = UrlParameter.Optional,
status = UrlParameter.Optional }
);
Routine defined like above works fine when I'm entering all parameters, but when some parameters are equal to null routing fails (for example "user/find,,,")
According to Clicktricity comment bellow - the singature of action method that handes the request:
public ActionResult Find(string userName, int? page, int? status)
{
// [...] some actions to handle the request
}
On the beginning I was testing the route by VS debugger, now I'm using route debugger described on Phil's Haack blog. The tool confirm - that routing with null values is not properly handled (or I'm doing something wrong ;) )

As far as I know .Net routing doesn't let you do multiple nullable parameters like that. Multiple parameters will only work if they are missing working backwards from the end and with the separator also missing so you'd get matches on
user/find,bob,2,live
user/find,bob,2
user/find,bob
user/find
It'd be a lot easier to use querystrings for what you're trying to do.
Edit based on comment:
If this is necessary then you could try doing it this way (though it's not a nice approach)
Change your path to match
{Controller}/{Action},{*parameters}
Make sure to put a constraint on the action and controller so this is limited to as few as possible.
Rename each action that would take your full list to something else, adding a standard prefix to each one would be the cleanest way, and add the [NonAction] attribute. Add a new method with the original name that takes a string, this string is a comma separated string of your variables. In this method split the string and return the original action passing in the values from the split.
So you go from:
public ActionResult Find(string name, int page, string status){
//Do stuff here
return View(result);
}
To
public ActionResult Find(string parameters){
string name;
int? page;
string status;
//split parameters and parse into variables
return FindAction(name, page, status);
}
[NonAction]
public ActionResult FindAction(string parameters){
//Do what you did in your previous Find action
return View(results);
}

Related

call two different rest methods with same URI

I have two Rest URIs :
// URI n1 : GET /users/{userName}
public ResponseEntity<userDto> findUserByName(
#PathVariable( value = "userName", required = true)
String userName
);
// URI n2 : GET /users/{userID}
public ResponseEntity<userDto> findUserByID(
#PathVariable( value = "userID", required = true)
Long userID
);
When I call GET /users/SuperUser123 I want the first function to respond and when I call GET /users/1854 I want the second one respond. What really happens is that the first function is always called for both cases (as the param is always of type String).
So how can I achieve what I want while respecting REST API URI recommendations ?
It will give ambiguous mapping runtime exception as the url pattern is same for both the methods.
If your url has some pattern like starting for superuser or something then you can use regex patterns to make it work.
In below example first method method will get called if the path variable is a digit otherwise second method for alphabets.you can change regex pattern accordingly.
#RequestMapping("{id:[0-9]+}")
public String handleRequest(#PathVariable("id") String userId, Model model){
model.addAttribute("msg", "profile id: "+userId);
return "my-page";
}
#RequestMapping("{name:[a-zA-Z]+}")
public String handleRequest2 (#PathVariable("name") String deptName, Model model) {
model.addAttribute("msg", "dept name : " + deptName);
return "my-page";
}

Spring MVC REST

I'm using Spring MVC and I have a controller mapped to a url lets call it example. I also have a method called show that allows me to view one of my examples based on an id.
#RequestMapping("/example")
#RequestMapping(value = "/{id}", produces = "text/html")
public String show(#PathVariable("id") String id, Model model) {
//Do some stuff and return a view
}
The problem is that the id is a URI and it has forward slashes. (e.g. test/case/version/sample might be an id so the resulting url is example/test/case/version/sample) so as a result my application gives me an error "Requested resource not found". I can't easily change the format of these ids. It's a list given to me that I have to work with. Is there a way around this? Thanks in Advance.
You can try using Regular expressions on the #PathVariable.
Like this from the Spring Docs:
#RequestMapping("/spring-web/{symbolicName:[a-z-]+}-{version:\\d\\.\\d\\.\\d}{extension:\\.[a-z]+}")
public void handle(#PathVariable String version, #PathVariable String extension) {
// ...
}
}
You'll just have to think on a regular expression that matches the "example/test/case/version/sample" that is your expression.
See the title: "URI Template Patterns with Regular Expressions"
on this page: http://static.springsource.org/spring/docs/3.2.x/spring-framework-reference/html/mvc.html for more information

Optional route parameters and action selection

I use the default route definition:
{controller}/{action}/{id}
where id = UrlParameter.Optional. As much as I understand it this means when id is not being part of the URL this route value will not exists in the RouteValues dictionary.
So this also seems perfectly possible (both GET):
public ActionResult Index() { ... } // handle URLs: controller/action
public ActionResult Index(int id) { ... } // handle URLs: controller/action/id
When id is missing the first action would be executed, but when id is present, the second one would execute. Fine, but it doesn't work. It can't resolve actions.
How can I accomplish this?
I'm thinking of writing a custom action method selector attribute like:
[RequiresRouteValue(string valueName)]
This would make it possible to use this kind of action methods. But is this the only way of doing it?
Is there something built-in I can hang on to?
Use either:
[HttpGet]
public ActionResult Index() { ... } // handle URLs: controller/action
[HttpPost]
public ActionResult Index(int id) { ... } // handle URLs: controller/action/id
Or just have one with a nullable param:
public ActionResult Index(int? id) { ... } // handles both instances
EDIT:
Would something like this work?
routes.MapRoute(
"Default", // Route name
"{controller}/{action}/", // URL with parameters
new { controller = "Login", action = "Index" } // Parameter defaults
);
routes.MapRoute(
"DefaultWithValue", // Route name
"{controller}/{action}/{id}", // URL with parameters
new { controller = "Login", action = "Index", id = UrlParameter.Optional } // Parameter defaults
);
Well from the exception that action can't be determines is pretty clear that actions are resolved first then data binder comes into play and examines action's parameters and tries to data bind values to them. Makes perfect sense.
This makes perfect sense. There would be no point in first trying to data bind values to all possible types and see what we get and then look for an appropriate action. That would be next to impossible.
So. Since action selection is the problem here I guess the best (and only) way to solve this (if I don't want to use a multifaceted single action method) is to write a custom action method selector attribute.
You can read all the details and get the code on my blog:
Improving Asp.net MVC maintainability and RESTful conformance

Can my MVC2 app specify route constraints on Query String parameters?

My MVC2 app uses a component that makes subsequent AJAX calls back to the same action, which causes all kinds of unnecessary data access and processing on the server. The component vendor suggests I re-route those subsequent requests to a different action. The subsequent requests differ in that they have a particular query string, and I want to know whether I can put constraints on the query string in my route table.
For example, the initial request comes in with a URL like http://localhost/document/display/1. This can be handled by the default route. I want to write a custom route to handle URLs like http://localhost/document/display/1?vendorParam1=blah1&script=blah.js and http://localhost/document/display/1?vendorParam2=blah2&script=blah.js by detecting "vendor" in the URL.
I tried the following, but it throws a System.ArgumentException: The route URL cannot start with a '/' or '~' character and it cannot contain a '?' character.:
routes.MapRoute(
null,
"Document/Display/{id}?{args}",
new { controller = "OtherController", action = "OtherAction" },
new RouteValueDictionary { { "args", "vendor" } });
Can I write a route that takes the query string into account? If not, do you have any other ideas?
Update: Put simply, can I write routing constraints such that http://localhost/document/display/1 is routed to the DocumentController.Display action but http://localhost/document/display/1?vendorParam1=blah1&script=blah.js is routed to the VendorController.Display action? Eventually, I would like any URL whose query string contains "vendor" to be routed to the VendorController.Display action.
I understand the first URL can be handled by the default route, but what about the second? Is it possible to do this at all? After lots of trial and error on my part, it looks like the answer is "No".
QueryString parameters can be used in constraints, although it's not supported by default. Here you can find an article describing how to implement this in ASP.NET MVC 2.
As it is in Dutch, here's the implementation. Add an 'IRouteConstraint' class:
public class QueryStringConstraint : IRouteConstraint
{
private readonly Regex _regex;
public QueryStringConstraint(string regex)
{
_regex = new Regex(regex, RegexOptions.IgnoreCase);
}
public bool Match (HttpContextBase httpContext, Route route, string parameterName, RouteValueDictionary values, RouteDirection routeDirection)
{
// check whether the paramname is in the QS collection
if(httpContext.Request.QueryString.AllKeys.Contains(parameterName))
{
// validate on the given regex
return _regex.Match(httpContext.Request.QueryString[parameterName]).Success;
}
// or return false
return false;
}
}
Now you can use this in your routes:
routes.MapRoute("object-contact",
"{aanbod}",
/* ... */,
new { pagina = new QueryStringConstraint("some|constraint") });
You don't need a route for this. It is already handled by the default model binder. Query string parameters will be automatically bound to action arguments:
public ActionResult Foo(string id, string script, string vendorname)
{
// the id parameter will be bound from the default route token
// script and vendorname parameters will be bound from the request string
...
}
UPDATE:
If you don't know the name of the query string parameters that will be passed you could loop through them:
foreach (string key in Request.QueryString.Keys)
{
string value = Request.QueryString[key];
}
This post is old, but couldn't you write a route before your default route
this would only catch routes with "vendor" in the args
routes.MapRoute(
null,
"Document/Display/{id}?{args}",
new { controller = "VendorController", action = "OtherAction" },
new {args=#".*(vendor).*"}//believe this is correct regex to catch "vendor" anywhere in the args
);
And This would catch the rest
routes.MapRoute(
null,
"Document/Display/{id}?{args}",
new { controller = "DisplayController", action = "OtherAction" }
);
Haven't tried this and I am a novice to MVC but I believe this should work?? From what I understand if the constraint doesn't match the route isn't used. So it would test the next route. Since your next route doesn't use any constraint on the args, it should, match the route.
I tried this out and it worked for me.

Handling MVC2 variables with hyphens in their name

I'm working with some third-party software that creates querystring parameters with hyphens in their names. I was taking a look at this SO question and it seems like their solution is very close to what I need but I'm too ignorant to the underlying MVC stuff to figure out how to adapt this to do what I need. Ideally, I'd like to simply replace hyphens with underscores and that would be a good enough solution. If there's a better one, then I'm interested in hearing it.
An example of a URL I want to handle is this:
http://localhost/app/Person/List?First-Name=Bob&My-Age=3
with this Controller:
public ActionResult List(string First_Name, int My_Age)
{
{...}
}
To repeat, I cannot change the querystring being generated so I need to support it with my controller somehow. But how?
For reference, below is the custom RouteHandler that is being used to handle underscores in controller names and action names from the SO question I referenced above that we might be able to modify to accomplish what I want:
public class HyphenatedRouteHandler : MvcRouteHandler
{
protected override IHttpHandler GetHttpHandler(RequestContext requestContext)
{
requestContext.RouteData.Values["controller"] = requestContext.RouteData.Values["controller"].ToString().Replace("-", "_");
requestContext.RouteData.Values["action"] = requestContext.RouteData.Values["action"].ToString().Replace("-", "_");
return base.GetHttpHandler(requestContext);
}
}
Have you tried [Bind(Prefix="First-name")]? It might work...
One way would be with a custom model binder. Another way would be with an action filter. Use the model binder if you want to do this on a specific type. Use the action filter if you want to do this on a specific action or controller. So for the latter method you could do something like:
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
var keys = filterContext.HttpContext.Request.QueryString.AllKeys.Where(k => k.Contains('-'));
foreach(var k in keys)
{
filterContext.ActionParameters.Add(
new KeyValuePair<string, object>(
k.Replace('-', '_'), filterContext.HttpContext.Request.QueryString[k]));
}
base.OnActionExecuting(filterContext);
}
I had the same problem. In the end rather than doing something too complex I just get the query string parameters using
string First_Name = Request["First-Name"];
You may want to check for NUlls incase the parameter is not there, but this sorted it out for me. You can also include an optional parameter for the ActionResult for test purposes etc..