#Sitecore 7.5/8.0, Web API and Attribute Routing

If you are working with Sitecore 7.5 or later you might have run into issues with getting Attribute Routing to work with Web API.

With Sitecore 7.5 Sitecore added some web services to their product which are configured in the initialize pipeline.

<processor type="Sitecore.Services.Infrastructure.Sitecore.Pipelines.ServicesWebApiInitializer,
                 Sitecore.Services.Infrastructure.Sitecore" 
           patch:source="Sitecore.Services.Client.config" />

When configuring their services they also replace the default IHttpControllerSelector with their own implementation NamespaceHttpControllerSelector which doesn't support Attribute Routing.

The workaround is to create an IHttpControllerSelector that supports both and patch in it after Sitecore's configuration. This way Sitecore's own stuff will keep working while we can also use Attribute Routing.

Krusen.Sitecore.WebApi

Use this nuget package if you just want Web API 2 and Attribute Routing to work with your Sitecore 7.5 or Sitecore 8 solution.

It comes with a compiled assembly that takes care of mapping the routes and is patched into the initialize pipeline.

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
    <pipelines>
      <initialize>
        <processor type="Krusen.Sitecore.WebApi.ConfigureAttributeRouting, Krusen.Sitecore.WebApi"
                   patch:after="processor[@type='Sitecore.Services.Infrastructure.Sitecore.Pipelines.ServicesWebApiInitializer, Sitecore.Services.Infrastructure.Sitecore']" />
      </initialize>
    </pipelines>
  </sitecore>
</configuration>

The only thing it does is this:

public void Process(PipelineArgs args)
{
    // Map Attribute Routes
    GlobalConfiguration.Configure(config => config.MapHttpAttributeRoutes());
    
    // Replace IHttpControllerSelector with our custom implementation
    GlobalConfiguration.Configure(ReplaceControllerSelector);
}

private static void ReplaceControllerSelector(HttpConfiguration config)
{
    config.Services.Replace(typeof (IHttpControllerSelector),
        new CustomHttpControllerSelector(config, new NamespaceQualifiedUniqueNameGenerator()));
}

The CustomHttpControllerSelector class is just a copy of Sitecore's NamespaceHttpControllerSelector except when trying to find the controller to use for the request it falls through to DefaultHttpControllerSelector if the controller route variable is missing from the request.

Krusen.Sitecore.WebApi.Custom

Use this nuget package if you have special needs or just want to have complete control of the code in your project.

The code needed is added to your project and will be patched into the initialize pipeline as with the other package.

Your project will need to reference Sitecore.Kernel and Sitecore.Services.Core to be able to build.