OData v4 Function always returns 404

Question

Trying to move from OData v3 to OData v4. Why do I keep getting a 404 when trying to use OData Functions?

Web API Config:

ODataModelBuilder builder = new ODataConventionModelBuilder();
//etc
builder.EntitySet<LocalizableString>("LocalizableStringApi");
//etc
var getComparitiveTableFunction = builder.EntityType<LocalizableString>().Collection.Function("GetComparitiveTable");
getComparitiveTableFunction.Parameter<string>("cultureCode");
getComparitiveTableFunction.ReturnsCollection<ComparitiveLocalizableString>();
//etc
config.MapODataServiceRoute("OData_Kore_CMS", "odata/kore/cms", builder.GetEdmModel());

C# Code:

[EnableQuery(AllowedQueryOptions = AllowedQueryOptions.All)]
[HttpGet]
//[ODataRoute("Default.GetComparitiveTable(cultureCode={cultureCode})")] // Tried this, but gets errors and I noticed the function is in the OData model anyway without this, so should be fine.
public virtual IHttpActionResult GetComparitiveTable([FromODataUri] string cultureCode)
{
    // Implementation
    return Ok(query);
}

XML Returned from $metadata:

<Schema Namespace="Default">
    <Function Name="GetComparitiveTable" IsBound="true">
        <Parameter Name="bindingParameter" Type="Collection(Kore.Localization.Domain.LocalizableString)"/>
        <Parameter Name="cultureCode" Type="Edm.String" Unicode="false"/>
        <ReturnType Type="Collection(Kore.Localization.Models.ComparitiveLocalizableString)"/>
    </Function>
    ...

As you can see, it's in the schema / OData model... yet the following query does not work:

http://localhost:30863/odata/kore/cms/LocalizableStringApi/Default.GetComparitiveTable(cultureCode='en-US')

I have also tried the following:

http://localhost:30863/odata/kore/cms/LocalizableStringApi/GetComparitiveTable(cultureCode='en-US')
http://localhost:30863/odata/kore/cms/Default.GetComparitiveTable(cultureCode='en-US')
http://localhost:30863/odata/kore/cms/GetComparitiveTable(cultureCode='en-US')

All of the above result in a 404.

So... what am I doing wrong here?

Answer 1

I solve a similar problem adding a trailing slash to the requested url.

Answer 2

I solved this by adding the following line in my web.config, under <system.webServer>:

<modules runAllManagedModulesForAllRequests="true">

This may cause performance issues though, if I remember correctly. So it's not ideal. Any better solutions are very welcome...

Answer 3

You need a module that goes by the name of UrlRoutingModule-4.0 to be running through IIS. This solution causes all your registered HTTP modules to run on every request, not just managed requests (e.g. .aspx). This means modules will run on ever .jpg .gif .css .html .pdf etc.

So, a better solution would be to add the following in your web.config

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

Source: http://www.britishdeveloper.co.uk/2010/06/dont-use-modules-runallmanagedmodulesfo.html

Answer 4

This is a solution to prevent 404 Not Found error with OData functions / actions.

Benefits of this solution

• Works with OData URI without slash at end (example: http://domain.org/odata/Objects/ObjectService.Action)
• Works with OData URI with a slash at end (example: http://domain.org/odata/Objects/ObjectService.Action/)
• Doesn't cause any performance issue.

Add theses lines in your web.config

<system.webServer>
    <handlers>
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0Custom" path="/odata*" verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers>
  </system.webServer>

Et Voilà :)