Why is my Web API method with double args not getting called?

Question

I have a Web API method that takes two double args:

Repository interface:

public interface IInventoryItemRepository
{
. . .
    IEnumerable<InventoryItem> GetDepartmentRange(double deptBegin, double deptEnd);
. . .
}

Repository:

public IEnumerable<InventoryItem> GetDepartmentRange(double deptBegin, double deptEnd)
{
    // Break the doubles into their component parts:
    int deptStartWhole = (int)Math.Truncate(deptBegin);
    int startFraction = (int)((deptBegin - deptStartWhole) * 100);
    int deptEndWhole = (int)Math.Truncate(deptEnd);
    int endFraction = (int)((deptBegin - deptEndWhole) * 100);

    return inventoryItems.Where(d => d.dept >= deptStartWhole).Where(e => e.subdept >= startFraction)
        .Where(f => f.dept <= deptEndWhole).Where(g => g.subdept >= endFraction);
}

Controller:

[Route("api/InventoryItems/GetDeptRange/{BeginDept:double}/{EndDept:double}")]
public IEnumerable<InventoryItem> GetInventoryByDeptRange(double BeginDept, double EndDept)
{
    return _inventoryItemRepository.GetDepartmentRange(BeginDept, EndDept);
}

When I try to invoke this method, via:

http://localhost:28642/api/inventoryitems/GetDeptRange/1.1/99.99

...I get, "HTTP Error 404.0 - Not Found The resource you are looking for has been removed, had its name changed, or is temporarily unavailable."

The related methods run fine (other methods on this Controller).

Answer 1

I was able to reproduce this on my machine.

Simply adding a / to the end of the URL corrected it for me. Looks like the routing engine is viewing it as a .99 file extension, rather than an input parameter.

http://localhost:28642/api/inventoryitems/GetDeptRange/1.1/99.99/

Additionally, it looks like you can register a custom route that automatically adds a trailing slash to the end of the URL when using the built-in helpers to generate the link. I have not tested this personally: stackoverflow Add a trailing slash at the end of each url

The easiest solution is to just add the following line to your RouteCollection. Not sure how you would do it with the attribute, but in your RouteConfig, you just add this:

routes.AppendTrailingSlash = true;

Answer 2

As noted by Joel, this is probably IIS picking up on the file extension and trying to serve a static file. You can get around this by adding the following into your web.config file (under system.webServer):

<modules>
    <remove name="UrlRoutingModule-4.0" />
    <add name="UrlRoutingModule-4.0" type="System.Web.Routing.UrlRoutingModule"
               preCondition="" />
</modules>

By default, IIS will only run this module for what it deems to be requests for ASP.NET resources - the above removes this condition on a per-site basis, allowing you to route all requests through ASP.NET MVC/Web API routing.

Static files will still be preferred if they exist, so this shouldn't cause any issues elsewhere.