Raven + Nancy Pipeline

gistfile1.cs

    public static class RavenPipelineExtensions
    {
        public static void EnableRaven(this IPipelines pipelines, IDictionary<string, IDocumentStore> documentStores,
                                       string ravenSessionKey)
        {
            documentStores.Keys.ForEach(
                database =>
                    {
                        var key = ravenSessionKey + "." + database;
                        var documentStore = documentStores[database];

                        pipelines.BeforeRequest.AddItemToStartOfPipeline(
                            context =>
                                {
                                    context.Items[key] = documentStore.OpenSession();
                                    return null;
                                });

                        pipelines.AfterRequest.AddItemToEndOfPipeline(
                            context =>
                                {
                                    dynamic session;
                                    if (false == context.Items.TryGetValue(key, out session) || session == null)
                                    {
                                        return;
                                    }

                                    using (session)
                                    {
                                        // if you return an error code and you really want raven to save you need to do it yourself.
                                        if ((int)context.Response.StatusCode >= 400) 
                                        {
                                            return;
                                        }
                                        session.SaveChanges();
                                    }
                                });

                        pipelines.OnError.AddItemToEndOfPipeline(
                            (context, _) =>
                                {
                                    dynamic session;
                                    if (context.Items.TryGetValue(key, out session) && session != null)
                                    {
                                        session.Dispose();
                                    }

                                    context.Items[key] = null;

                                    return null;
                                });
                    });
        }

        public static IDocumentSession RavenSession(this NancyContext context, string key = null)
        {
            return (IDocumentSession)context.Items["ravendb.session." + (key ?? Bootstrapper.DefaultRavenDatabase)];
        }
    }