trying to work with session variables , asking if given Session variable isn't null

Question

as the situation is described at the bottom(using Webworms not Mvc),

and as i probably need to "master" the implementation of Session variables, almost in every web application , I have constructed a dedicated class that will help me manage it easily.

the approach is as following

this first code block is for usage , you can see the class it is calling on, at the next code block

i am using misspelled names on purpose, to avoid ambiguity(without any prefix), ..and so i could find it much easier on intelliSense that way.

//'importing' the class for current project
using SeSn = Debug_Tests.Seseions.SeSn;

// creating an object (usually with name related to currentProject)
public static SeSn.CreatCurrentSesionVariablsStructNamed CurSesVarStruct = new Seseions.SeSn.CreatCurrentSesionVariablsStructNamed();

// the long name helps me in this little 'chaos'

so far, this is an instance of a struct, that is 'grouping' or 'tying' all my globals as one bundle,

so when ever i may need to store my global variables , i will assign the values into the appropriate-struct-variable CurSesVarStruct has to offer.

and then, all i need is to access session variables once, only to extract the "Variable-collection" -object , ... as it is actually a session variable, that i keep it's name constant - _CurrentSesionGlobals

i tried my best to describe the background , but in short:

it's the struct that is stored in session as one of the session variables - data type = object or you could say a clone of the struct to be saved between sessions.

so having that to work with _CurrentSesionGlobals, I could just access any value i need from session , through it as like in the following :

Assign the struct before storing it in Session:

CurSesVarStruct.SelectedUercustid = custID;

then the next method - ExtrctSesnVar() below, allows me to use for example:

Extract a variable that was saved in last session:

custID = ExtractSesnVar().SelectedUercustid;

so SelectedUercustid is actually one of the struct members.

The Problem

extraction of _CurrentSesionGlobals out of the session variables.

public static SeSn.CreatCurrentSesionVariablsStructNamed ExtrctSesnVar()
{
    var CurrAppGlobals = SeSn.GetValueAS.ACloneOfTheStructObj("_CurrentSesionGlobals");
    return (SeSn.CreatCurrentSesionVariablsStructNamed)CurrAppGlobals;
  //the question is refereing this location.
}

the question

How could i put a return value for null result,

or a condition that will first ask if the object / a given Session Variable, that i am trying to extract isn't null, or does not exist?

as it is now there's an exception error, while i am trying to get the value ... of a non-existing-session-variable.

the next code block .

it's a class that I add into the solution, as a helper to every website application.

it's actually a namespace. so the class that is responsible to handle session variables is Sesn

  namespace Seseions
  {
        public class Sesn
        {
         
            public static bool isNotEmpty()
            {
                return HttpContext.Current.Session.Keys.Count > 0;
            }


            public struct CreatCurrentSesionVariablsStructNamed
            {

                // some of commonly used variables- still testing options..

                public int ManagerCustID;
                public int SelectedUercustid;
                public int recordID;
                public int SelectedMonth;
                public int SelectedChosenWorker;
                public int SelectedYear ;

                
                public string SelectedTable;
                public string SelectedColumn;
                public string SqlSelectCommandLastQuery;
                public string TableOfUsersReference;
                public List<string> Fontlist { get; set; }

            }

            // converts and extract values of session variables

            public class GetValueAS
            {
                public static CreatCurrentSesionVariablsStructNamed ACloneOfTheStructObj(string currntProjectSesVarStructName)
                {
                    if(HttpContext.Current.Session[currntProjectSesVarStructName] != null)
                    return (CreatCurrentSesionVariablsStructNamed)HttpContext.Current.Session[currntProjectSesVarStructName];
                 
                }

                public static int _Int(string SesParameterValToReturn)
                {
                    return Convert.ToInt32(HttpContext.Current.Session[SesParameterValToReturn]);
                }

                public static string _String(string SesParameterValToReturn)
                {
                    return Convert.ToString(HttpContext.Current.Session[SesParameterValToReturn]);
                }
                public static DataSet _DataSet(string SesParameterValToReturn)
                {
                    return (DataSet)HttpContext.Current.Session[SesParameterValToReturn];
                }
                public static DataTable _DataTable(string SesParameterValToReturn)
                {
                    return (DataTable)HttpContext.Current.Session[SesParameterValToReturn];
                }
                public static bool _Bool(string SeSnVarToCheckOn)
                {
                    if (HttpContext.Current.Session[SeSnVarToCheckOn] == null)
                        return false;
                    return (bool)HttpContext.Current.Session[SeSnVarToCheckOn];
                }



            }

            // an easy way to access and mange session variables actions
      public enum Act
      {
                 Add, Remove, Replace
      }
            public static void Modify(Act action, string New_SesnVarName= null, object NewP_Value=null, string Currnt_Ses_SesnVarName=null)
            {
                switch (action)
                {
                    case Act.Remove:
                        if (isNotEmpty())
                            HttpContext.Current.Session.Remove(CurSes_ParamName);
                        break;
                    case Act.Replace:
                         HttpContext.Current.Session.Remove(CurSes_ParamName);
                         HttpContext.Current.Session.Add(New_SesnVarName, NewP_Value);
                        break;

                    case Act.Add:
                        HttpContext.Current.Session.Add(NewQs_SesnVarName, NewP_Value);
                        break;


                }


            }

        }
    }

Answer 1

Just don't do this.

• critical: do not put Session (user) related data in static variables. It is not thread-safe.
• best practice: try to avoid static in ASP.NET for everything else too.
• best practice: do not use structs for anything but small, immutable and identity-less types

It seems you are over-engineering this. All you need (for now) is to use some constants for the strings:

public static class SessionKeys
{
   public const string ManagerCustID = "ManagerCustID";
   ...
}

and then you can start focusing on code that adds value to your app.