MVC to WebApi calls losing session - asp.net

Question

I am using MVC and WebApi in same project, not using Session in WebApi.
In MVC BaseController I have something along these line
protected const string HOME = "HOME";
protected SessionDataStore SessionDataStore
{
get
{
if ((Session[HOME] != null) && (Session[HOME] is SessionDataStore))
{
return (SessionDataStore)Session[HOME];
}
}
set
{
Session[HOME] = value;
}
}
public class SessionDataStore
{
public Request CurrentRequest { get; set; }
public Customer CurrentCustomer { get; set; }
public List<Salutation> Salutations { get; set; }
public WebServiceConfiguration CurrentConfiguration { get; set; }
public List<int> CurrentConfigurationIds { get; set; }
public List<int> CurrentAttributeIds { get; set; }
public SessionDataStore()
{
CurrentRequest = new Request();
CurrentCustomer = new Customer();
Salutations = new List<Salutation>()
{
new Salutation() { Id = 1, Name = "Mr", },
new Salutation() { Id = 2, Name = "Mrs", },
new Salutation() { Id = 3, Name = "Miss", },
new Salutation() { Id = 4, Name = "Ms", },
new Salutation() { Id = 5, Name = "Dr", },
new Salutation() { Id = 6, Name = "Prof", },
new Salutation() { Id = 7, Name = "Other", }
};
CurrentConfiguration = new WebServiceConfiguration();
CurrentConfigurationIds= new List<int>();
CurrentAttributeIds = new List<int>();
}
}
In my MVC project, I call the web API and update the Session object like this.
I initialise SessionDataStore in the index page to a new object
var client = new HttpClient(_handler);
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
HttpResponseMessage response = client.GetAsync(string.Concat(GetBaseUrl().AbsoluteUri + "api/request/", requestId)).Result;
SessionDataStore.CurrentRequest = response.IsSuccessStatusCode ? response.Content.ReadAsAsync<Request>().Result : null;
The status code is Success but then I am losing the session.
Not sure why this is happening. I am using inProc session

Answer 1

Web API is REST-compliant, and REST is stateless. In other words, no session. You cannot access the session in a Web API action. If you need to interact with the session via an AJAX call, you will need to simply create an MVC Controller action to handle it instead of a Web API ApiController action.

Answer 2

If you didn't find the answer yet, this is how you can enable session usage inside web api request. You have to write the Application_PostAuthorizeRequest inside the Global.asax.cs like this:
protected void Application_PostAuthorizeRequest()
{
if(IsWebApiRequest())
HttpContext.Current.SetSessionStateBehavior(SessionStateBehavior.Required);
}
private bool IsWebApiRequest()
{
return HttpContext.Current.Request.AppRelativeCurrentExecutionFilePath.Contains("/api/");
}