User1120430333 posted
I'll give you the breakdown on how the Community Of Practice (CoP) object was kept in state for a user using the application. The CoP object is a container object for all the DTO(s) Data Transfer Objects for certain Web pages and areas on a Web page. The
public properties of a DTO were bound to the controls on a given page. So as the user moved to page to page, the CoP object was serialized and persisted to the State table every time the Page_Unload was done, which was done on a spawned async thread so
that it wouldn't interfere with the responsiveness of the overall application's speed.
The key here is what is being called a Session-id. It is a GUID assigned to the user when the user logged into the application. Each page has a hidden field on the page to hold the GUID. The Session-id was obtained from the page, and the key was formulated
to go after the last State record for the user in the State table anytime the CoP object was found not to be in session with the CoP object being a null value object due to session timeout. The retrieval of the CoP object for a user is based on the last known
object for the user in the State table. The CoP object was deserialized and put back into session. Like I said, as long as a page was up in the browser and the machine was on after a session timeout, the last known CoP object in the State table for the user
was retrieved and the CoP object put back into session as if there was no session timeout.
There was a little batch program that ran everyday to delete any State records that were like 30 days old or ran whenever needed as the State table had a lot records in it due the application was a high volume usage application.
The State record was no more than a composite-key with nvarchar of like 3,000 or something holding the XML serialized CoP with its DTO(s) in it.
I hope you get the jest of it which is no more than XML serialization and deserialization of an object persisted to the DB. Find out how to spawn an async thread to save he Cop object to State table. I couldn't find the code. It's a big project
from year 2008, and I am tired of going down the rabbit hole trying to find that code on the backend.
HTH
protected override void OnInit(EventArgs e)
{
ModuleIsInCoP(enumModuleID.MOD_USER_ADMINISTRATION);
GetMode(Request.QueryString["Mode"]);
sessionguid = Request.QueryString["SG"];
SetSecurity();
CheckSession();
SetTabClickEvents();
#region Check the CoP Object
var cop = new DTOCoP();
if (CoP != null)
{
cop = CoP;
}
else
{
if (Mode == CCMMode.Creation)
{
CurCoPID = 0;
}
else
{
CurCoPID = CoPID;
}
var _CoPPresenter = new CoPPresenter(this);
CurUserID = UserID;
CurSessionID = "COPCM" + sessionguid;
_CoPPresenter.GetCoPStateObject();
cop = CoP;
}
#endregion
hfCopDirty.Value = cop.IsCopOrChildDirty.ToString();
if (!Page.IsPostBack)
{
LoadValues(cop);
}
else
{
ReloadNeighborhoods(cop);
}
CheckTabs(cop);
base.OnInit(e);
}
protected void Page_Load(object sender, EventArgs e)
{
ModuleIsInCoP(enumModuleID.MOD_USER_ADMINISTRATION);
GetMode(Request.QueryString["Mode"]);
SetSecurity();
CheckSession();
SetTabClickEvents();
ConfirmMode(Request.QueryString["Mode"]);
if (Page.IsPostBack)
ReloadNeighborhoods(CoP);
if (Mode == CCMMode.Creation)
LockDownTabs(CoP.CurrentTab);
CheckTabs(CoP);
}
protected void Page_Unload(object sender, EventArgs e)
{
SaveCoPStateObject();
}
#region Save CoP object to state table
private void SaveCoPStateObject()
{
var _CoPPresenter = new CoPPresenter(this);
CurUserID = UserID;
CurSessionID = "COPCM" + sessionguid;
_CoPPresenter.SaveCoPStateObject();
}
#endregion
#region Delete CoP objects from state table
private void DeletCoPStateObjects(object aobj)
{
Int32 copid = CoP.ID;
Session["CoPObj" + sessionguid] = null;
if (Mode == CCMMode.Creation)
copid = 0;
mCommunityService.DeleteCoPStataObjects(UserID, "COPCM" + sessionguid, copid);
}
public void SaveCoPStateObject()
{
if (mView.CoP != null)
{
var client = new CommunityClient();
client.SaveCoPStateObject(mView.CurUserID, mView.CurSessionID, mView.CoP.ID,
SerializeAnObject(mView.CoP));
client.Close();
}
}
public void GetCoPStateObject()
{
var client = new CommunityClient();
mView.CoP =
DeSerializeAnObject(client.GetCoPStateObject(mView.CurUserID, mView.CurSessionID, mView.CurCoPID), typeof(DTOCoP)) as DTOCoP;
client.Close();
}
private static string SerializeAnObject(object AnObject)
{
var XmlDoc = new XmlDocument();
var Xml_Serializer = new XmlSerializer(AnObject.GetType());
var MemStream = new MemoryStream();
try
{
Xml_Serializer.Serialize(MemStream, AnObject);
MemStream.Position = 0;
XmlDoc.Load(MemStream);
return XmlDoc.InnerXml;
}
finally
{
MemStream.Close();
}
}
private static Object DeSerializeAnObject(string XmlOfAnObject, Type ObjectType)
{
if (XmlOfAnObject == string.Empty)
{
var client = new CommunityClient();
var DTOCoP = Translate(client.GetNewCop());
DTOCoP.SessionID = "Redirect";
client.Close();
return DTOCoP;
}
var StrReader = new StringReader(XmlOfAnObject);
var Xml_Serializer = new XmlSerializer(ObjectType);
var XmlReader = new XmlTextReader(StrReader);
try
{
Object AnObject = Xml_Serializer.Deserialize(XmlReader);
return AnObject;
}
finally
{
XmlReader.Close();
StrReader.Close();
}
}
}
using System;
using System.Data.Objects;
using System.Linq;
using KN.Tiers.Community.DAL.Model;
using System.Transactions;
using System.Data.EntityClient;
namespace KN.Tiers.Community.DAL
{
public class CoPObjectState
{
#region private methods
private const string mwdb = "name=MainWebDBEntities1";
private static readonly Func<MainWebDBEntities1, int, string, int, IQueryable<CoP_ObjState>> compiledQueryCoPObjState =
CompiledQuery.Compile((MainWebDBEntities1 ctx, int userid, string sessionid, int copid) =>
(from a in ctx.CoP_ObjState.Where(a => a.UserID == userid
&& a.SessionID == sessionid && a.CopID == copid)
.OrderByDescending(a => a.TimeStamp)
select a));
#endregion
public static string GetCoPStateObject(Int32 userid, string sessionid, Int32 copid)
{
var strreturn = string.Empty;
//set it to read uncommited
var transactionOptions = new TransactionOptions
{
IsolationLevel = IsolationLevel.ReadUncommitted
};
//create the transaction scope, passing our options in
using (var transactionScope = new TransactionScope(TransactionScopeOption.Required, transactionOptions))
using (var conn = new EntityConnection(mwdb))
using (var db = new MainWebDBEntities1(conn))
try
{
var stateobjs = compiledQueryCoPObjState.Invoke(db, userid, sessionid, copid).ToList();
foreach (var stateobj in stateobjs)
{
strreturn = stateobj.CoP_Object;
break;
}
transactionScope.Complete();
}
finally
{
conn.Close();
}
return strreturn;
}
public static void SaveCoPStateObject(Int32 userid, string sessionid, Int32 copid, string AnObject)
{
using (var conn = new EntityConnection(mwdb))
using (var db = new MainWebDBEntities1(conn))
try
{
var objstate = new CoP_ObjState
{
UserID = userid,
SessionID = sessionid,
CopID = copid,
TimeStamp = DateTime.Now.AddSeconds(2).AddMilliseconds(100),
CoP_Object = AnObject
};
db.AddToCoP_ObjState(objstate);
db.SaveChanges();
}
finally
{
conn.Close();
}
}
public static void DeleteCoPStataObject(Int32 userid, string sessionid, Int32 copid)
{
using (var conn = new EntityConnection(mwdb))
using (var db = new MainWebDBEntities1(conn))
try
{
using (var scope = new TransactionScope())
{
var stateobjs = compiledQueryCoPObjState.Invoke(db, userid, sessionid, copid).ToList();
foreach (var stateobj in stateobjs)
{
db.DeleteObject(stateobj);
db.SaveChanges();
}
scope.Complete();
}
}
finally
{
conn.Close();
}
}
}
}
