How to Pass Model to Session in MVC Core

I have an application that has Role based login system. In Login View when we press the Login button an Action Method is called that retrieves the User Righs of the current user from the UserRights table and assign the query result to the Model class MenuModels. I want to assign the MenuModels class in to Session to create dyunamic menu for the current user but the Session does not work in MVC Core. Fiollowing is my Code:

//Get the User Rights Assignments or names of the Sub Menu Items assigned to the current selected user from the UserRightsDetails table joining with the MainMenu and SubMenu tables because the UserRightsDetails table only contains IDs of the Main Menu //items and Sub Menu Items

IEnumerable menuDetails = (from userRights in dbContext.UserRightsDetails

join mainMenu in dbContext.MainMenu

on userRights.MainMenuId equals mainMenu.MainMenuId

join subMenu in dbContext.SubMenu

on userRights.SubMenuId equals subMenu.SubMenuId

join uRole in dbContext.UserRoles

on userRights.RoleId equals uRole.RoleId

where userRights.RoleId == userRoleId

select new MenuModels

{

MainMenuId = mainMenu.MainMenuId,

MainMenuName = mainMenu.MainMenuName,

SubMenuId = subMenu.SubMenuId,

SubMenuName = subMenu.SubMenuName,

Controller = subMenu.Controller,

Action = subMenu.Action,

RoleId = uRole.RoleId,

RoleName = uRole.RoleName

}).ToList();

//Pass the Model data to Session

HttpContext.Session.SetSessionModelData("MenuMaster", menuDetails);

The SetSessionModelData is a function that i declared inside in the SessionExtentions class and i defined this class in the same controller where i used the above Linq Query. Following is my SessionExtentions class:

//Declare a Class to define a method that set and get the Complex data into session

public static class SessionExtensions

{

public static void SetSessionModelData(this ISession session, string key, object value)

{

session.SetString(key, JsonConvert.SerializeObject(value));

}

public static T GetSessionModelData(this ISession session, string key)

{

var data = session.GetString(key);

if (data == null)

{

return default(T);

}

return JsonConvert.DeserializeObject(data);

}

when i use the the GetSessionModelData() method in another Controller then it gives me the following error:

Newtonsoft.Json.JsonSerializationException: 'Cannot deserialize the current JSON array (e.g. [1,2,3]) into type 'HRandPayroll.Models.RetrieveDataModels.MenuModels' because the type requires a JSON object (e.g. {"name":"value"}) to deserialize correctly.

To fix this error either change the JSON to a JSON object (e.g. {"name":"value"}) or change the deserialized type to an array or a type that implements a collection interface (e.g. ICollection, IList) like List that can be deserialized from a JSON array. JsonArrayAttribute can also be added to the type to force it to deserialize from a JSON array.

Path '', line 1, position 1.'

Following is my call of Get method:

ViewBag.LoginSession = HttpContext.Session.GetSessionModelData("MenuMaster");

This call give me the above error message of deserialization. Please give me any idea. Thanks

Check if you are re-assigning session key MenuMaster somewhere in your code.

Also provide json which you are setting and also what you are retreving from session.

another solution is , create one extension method like bellow

public static class SessionExtensions
{
public static void SetSession(this ISession session, string key, object value)
{
session.SetString(key, JsonConvert.SerializeObject(value));
}
public static T GetSession(this ISession session, string key)
{
return JsonConvert.DeserializeObject(session.GetString(key));
}
}

then follow bellow approach to in your case

public IActionResult Index()
{
HttpContext.Session.SetSession("UserDetails", new UserContent
{
Username = "Intstrings",
Email = "[email protected]",
Roles = new List { "Admin" }
});
return Json(true);
}
public IActionResult About()
{
var userContent = HttpContext.Session.GetSession("UserDetails");
return Json(userContent);
}

return value == null ? default(T) : JsonConvert.DeserializeObject(value);

Dear Madan Sorab,

It converts object to json and reconverts to object but i want to serialize the query result into json and Deserialize the query result but when i deserialize it gives me error as menshioned above. Following is my Query Result:

IEnumerable menuDetails = (from userRights in dbContext.UserRightsDetails

join mainMenu in dbContext.MainMenu

on userRights.MainMenuId equals mainMenu.MainMenuId

join subMenu in dbContext.SubMenu

on userRights.SubMenuId equals subMenu.SubMenuId

join uRole in dbContext.UserRoles

on userRights.RoleId equals uRole.RoleId

where userRights.RoleId == userRoleId

select new MenuModels

{

MainMenuId = mainMenu.MainMenuId,

MainMenuName = mainMenu.MainMenuName,

SubMenuId = subMenu.SubMenuId,

SubMenuName = subMenu.SubMenuName,

Controller = subMenu.Controller,

Action = subMenu.Action,

RoleId = uRole.RoleId,

RoleName = uRole.RoleName

}).ToList();

//Pass the Model data to Session

HttpContext.Session.SetSessionModelData("MenuMaster", menuDetails);

The Serialization has successful but when i used the follwowing deserialize code then it gives me error:

ViewBag.LoginSession = HttpContext.Session.GetSessionModelData("MenuMaster");

What does your JSON look like when yout object has been converted?

JsonConvert.SerializeObject(value)

Maybe adding "{ \"menu\": [" + myJSON + "]}" can do the trick.

THe Problem is converting an IEnumerable does not automatically resuklt in an array if only one element within. So you need to Force it to be an Array!

namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
string[] request = new String[2];
request[0] = "Name";
request[1] = "Occupaonti";
string json = JsonConvert.SerializeObject(request);
}
}
}

Dear Mario Scheeren

I changed the code according to your recommendation but it did not solve my problem. It gives me the same error.

public static void SetSessionModelData(this ISession session, string key, T value)
{
session.SetString(key, JsonConvert.SerializeObject(value));
}

8 Replies

Know the answer? Post it — somebody with the same question will find it here.

Sagar Malde7y ago
Check if you are re-assigning session key MenuMaster somewhere in your code.

Also provide json which you are setting and also what you are retreving from session.
0
Madan Shekar7y ago
another solution is , create one extension method like bellow
public static class SessionExtensions
{
    public static void SetSession(this ISession session, string key, object value)
    {
        session.SetString(key, JsonConvert.SerializeObject(value));
    }

    public static T GetSession(this ISession session, string key)
    {
        return JsonConvert.DeserializeObject(session.GetString(key));
    }
}
then follow bellow approach to in your case
public IActionResult Index()
{
    HttpContext.Session.SetSession("UserDetails", new UserContent
    {
        Username = "Intstrings",
        Email = "[email protected]",
        Roles = new List { "Admin" }
    });
    return Json(true);
}

public IActionResult About()
{
    var userContent = HttpContext.Session.GetSession("UserDetails");
    return Json(userContent);
}
+1
Madan Shekar7y ago
1. return value == null ? default(T) : JsonConvert.DeserializeObject(value);
try this one T in the sense your collection and value in the sense data(data which u are going to deserialize)
0