/// <summary>
/// Mirrors the MVC PersistentControllerActivator for the WebSharper
/// context.
/// </summary>
/// <typeparam name="M"></typeparam>
/// <param name="viewModelAccessor">non-thread safe static reference to the ViewModel</param>
/// <returns></returns>
// [Remote] -> Yields "Remote methods must not be generic" from WebSharper:
// https://github.com/dotnet-websharper/core/issues/1048
public static M Load <M, V>(string viewState, out V viewModelAccessor, Storage?sessionStorage = null)
where M : class, IStored <M>, new()
where V : ViewModel <M>, new()
{
var storage = sessionStorage ?? StorageImplementation.GetStorage(Configuration, HttpContext);
var storageID = StorageImplementation.GetStorageID(typeof(M).Name);
var getQuery = RequestQuerySessionMiddleware.Query(HttpContext);
// Implements StorageImplementation.ClearIfRequested(HttpContext, storage, storageID)
// for WebSharper Ajax POST requests
if (getQuery != null &&
getQuery.TryGetValue("clear", out string getClear) &&
bool.TryParse(getClear, out bool _) &&
Once(OnceAction.Clear, storageID))
{
getQuery.TryGetValue("storage", out string getStorage);
Enum.TryParse <Storage>(getStorage, true, out Storage clearStorage);
StorageImplementation.Clear(HttpContext, clearStorage, storage, storageID);
}
V viewModel;
Guid sessionOverride;
Guid session;
byte[] bytes;
Func <byte[], byte[]> filter;
if (getQuery != null &&
getQuery.TryGetValue("session", out string getSession) &&
Guid.TryParse(getSession, out sessionOverride) &&
Once(OnceAction.Load, storageID))
{
// ---------- Direct Load Database ----------
viewModel = new V();
(bytes, filter) = StorageImplementation.DatabaseBytes(Configuration, HttpContext, storageID, sessionOverride);
viewModel.Main = (M)StorageImplementation.LoadFromBytes(() => new M(), bytes, filter);
}
else
{
// ---------- Load ViewState ----------
if (storage == Storage.ViewState)
{
viewModel = new V();
filter = StorageImplementation.DecryptViewState(Configuration);
viewModel.ViewState = viewState;
viewModel.DeserializeMain(filter);
}
// ---------- Load Session ----------
else if (storage == Storage.Session)
{
HttpContext.Session.TryGetValue(storageID, out bytes);
viewModel = new V();
viewModel.SetMain(StorageImplementation.LoadFromBytes(() => new M(), bytes));
}
// ---------- Load Database ----------
else if (storage == Storage.Database)
{
Guid.TryParse(HttpContext.Request.Cookies[storageID].FromCookieString()["session"], out session);
(bytes, filter) = StorageImplementation.DatabaseBytes(Configuration, HttpContext, storageID, session);
viewModel = new V();
viewModel.SetMain(StorageImplementation.LoadFromBytes(() => new M(), bytes, filter));
}
else
{
throw new NotImplementedException("Storage {0} not implemented");
}
}
// Now that an instance is guaranteed remember the storage type for Save() and the client.
viewModel.SessionStorage = storage;
viewModel.VSessionStorage = storage.ToString();
// An instantiated Main is now guaranteed -> make its members
// visible to WebSharper:
viewModel.LoadMembers();
// Include the ViewModel instance as member of the returned Main
viewModel.Main.ViewModel = viewModel;
// Set a reference to the ViewModel
viewModelAccessor = viewModel;
return(viewModel.Main);
}
/// <summary>
/// Custom Controller factory method returning a serialized object if available.
/// </summary>
/// <param name="actionContext"></param>
/// <returns></returns>
public object Create(ControllerContext actionContext)
{
object controller = null;
var controllerTypeInfo = actionContext.ActionDescriptor.ControllerTypeInfo;
var controllerType = controllerTypeInfo.AsType();
var storageID = StorageImplementation.GetStorageID(controllerTypeInfo.Name);
var sessionStorageID = StorageImplementation.GetSessionStorageID(controllerTypeInfo.Name);
var storage = StorageImplementation.GetStorage(this.Configuration, this.HttpContext, sessionStorageID);
StorageImplementation.ClearIfRequested(this.HttpContext, storage, storageID);
Guid sessionOverride;
Guid session;
byte[] bytes;
Func <byte[], byte[]> filter = null;
// ---------- Direct GET request ?session= from the Database ----------
if (this.HttpContext.Request.Method == WebRequestMethods.Http.Get &&
Guid.TryParse(this.HttpContext.Request.Query["session"], out sessionOverride))
{
using (var db = new ASP_DBEntities())
{
(bytes, filter) = StorageImplementation.DatabaseBytes(Configuration, HttpContext, storageID, sessionOverride);
controller = DeserializeController(actionContext, controllerTypeInfo, controllerType, bytes, filter);
}
}
else
{
// ---------- Load from ViewState ----------
if (storage == Storage.ViewState &&
this.HttpContext.Request.Method == WebRequestMethods.Http.Post &&
this.HttpContext.Request.Form.ContainsKey(storageID))
{
// input type=hidden from <input viewstate="@ViewBag.ViewState" />
var controllerString = this.HttpContext.Request.Form[storageID];
if (!String.IsNullOrEmpty(controllerString))
{
(bytes, filter) = StorageImplementation.ViewStateBytes(this.Configuration, controllerString);
controller = DeserializeController(actionContext, controllerTypeInfo, controllerType, bytes, filter);
}
}
// ---------- Load from Session ----------
else if (storage == Storage.Session &&
this.HttpContext.Session.TryGetValue(storageID, out bytes))
{
controller = DeserializeController(actionContext, controllerTypeInfo, controllerType, bytes);
}
// ---------- Load from Database ----------
else if (storage == Storage.Database &&
Guid.TryParse(this.HttpContext.Request.Cookies[storageID].FromCookieString()["session"], out session))
{
(bytes, filter) = StorageImplementation.DatabaseBytes(Configuration, HttpContext, storageID, session);
controller = DeserializeController(actionContext, controllerTypeInfo, controllerType, bytes, filter);
((IPersistentController)controller).Session = session;
}
// ---------- Load from X-ViewState Header ----------
else if (storage == Storage.Header &&
this.HttpContext.Request.Headers.ContainsKey(StorageImplementation.HeaderName))
{
// input type=hidden from <input viewstate="@ViewBag.ViewState" />
var controllerString = this.HttpContext.Request.Headers[StorageImplementation.HeaderName];
if (!String.IsNullOrEmpty(controllerString))
{
(bytes, filter) = StorageImplementation.ViewStateBytes(this.Configuration, controllerString);
controller = DeserializeController(actionContext, controllerTypeInfo, controllerType, bytes, filter);
}
}
if (controller == null)
{
// ASP.NET Core implementation, no persistence, just return the new controller
controller = actionContext.HttpContext.RequestServices.GetService(controllerType);
}
}
return(controller);
}