MAUI Droid Ntiers communication issue : Unable to read beyond the end of the stream

[sylum]

Hi Folks,

I am currently working on an MAUI project using CSLA6 and CSLA7Preview and I am facing an issue with the ntiers communication between android and the appserver.
Actually, the maui app windows works well with the ntiers communication but with android i got the following dataportal error :
Unable to read beyond the end of the stream.

Below, the github link to reproduce the issue base on the Rocky MauiExample projet
https://github.com/sylum/MauiExample_NTiers

Exception :

Csla.DataPortalException
  Message=Unable to read beyond the end of the stream.
  Source=Csla
  Arborescence des appels de procédure :

   at Csla.DataPortalClient.DataPortalProxy.Fetch(Type objectType, Object criteria, DataPortalContext context, Boolean isSync)
   at Csla.DataPortal`1.<DoFetchAsync>d__19[[BusinessLibrary.PersonList, BusinessLibrary, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].MoveNext()
   at Csla.DataPortal`1.<FetchAsync>d__24[[BusinessLibrary.PersonList, BusinessLibrary, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].MoveNext()
   at MauiExample.Pages.PersonListPage.<>c__DisplayClass3_0.<<RefreshData>b__0>d.MoveNext() in C:\RFit\Developpement\Csla\SOURCE\MauiExample\MauiExample\MauiExample\Pages\PersonListPage.xaml.cs:line 31
--- End of stack trace from previous location ---
   at Csla.Xaml.ViewModelBase`1.<RefreshAsync>d__69`1[[BusinessLibrary.PersonList, BusinessLibrary, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null],[BusinessLibrary.PersonList, BusinessLibrary, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]].MoveNext()
   at MauiExample.Pages.PersonListPage.RefreshData() in C:\RFit\Developpement\Csla\SOURCE\MauiExample\MauiExample\MauiExample\Pages\PersonListPage.xaml.cs:line 35
   at MauiExample.Pages.PersonListPage.OnAppearing() in C:\RFit\Developpement\Csla\SOURCE\MauiExample\MauiExample\MauiExample\Pages\PersonListPage.xaml.cs:line 20
   at System.Threading.Tasks.Task.<>c.<ThrowAsync>b__128_0(Object state)
   at Android.App.SyncContext.<>c__DisplayClass2_0.<Post>b__0() in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/Android.App/SyncContext.cs:line 36
   at Java.Lang.Thread.RunnableImplementor.Run() in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/Java.Lang/Thread.cs:line 36
   at Java.Lang.IRunnableInvoker.n_Run(IntPtr jnienv, IntPtr native__this) in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/obj/Release/net7.0/android-33/mcw/Java.Lang.IRunnable.cs:line 84
   at Android.Runtime.JNINativeWrapper.Wrap_JniMarshal_PP_V(_JniMarshal_PP_V callback, IntPtr jnienv, IntPtr klazz) in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/Android.Runtime/JNINativeWrapper.g.cs:line 22

Does someone has already encounter this issue ?

Thanks a lot for you feedback in advance,

Best regards,
Cedric

Version and Platform
CSLA : 6.2.2 and 7.0.0-R23042601
MAUI : WIN & DROID
VS2022
WINDOW11

[rockfordlhotka]

In my experience this often means that the server is returning a 500 or other unexpected result, so the data portal on the client isn't actually getting a result from the data portal on the server, but rather from the web server (or some other middleware).

If you are using the Android emulator, remember that it can't access your PCs localhost. I think there might be ways around that? I usually just host the appserver in Azure so it has a public IP address to solve the issue.

[sylum]

Hi Rocky,

Thx for your answer. Actually, I'm using an Android Mobile (a real one) to access the appserver who is hosted by IIS on my PC.

In short, with the application running on Windows, I can have access to the appserver and everything works well but with the same application running on Android mobile, i'm still keeping the error : Unable to read beyond the end of the stream.

However, the appserver can be reached by the android mobile (using the dataportal URL into chrome like below).

I feel like I'm missing something obvious.
Does anyone have a idea or sample showing MAUI N-tiers on android.

Thanks a lot for you help,

Best regards,
Cedric

[sylum]

Just in case to complete my previous post, i put below the client dataportal configuration (droid)

and below the appserver dataportal configuration

[rockfordlhotka]

Looking at HttpProxy, it catches the WebException and puts the stream contents into a Message field to help debugging.

It might be that this exception with more detail is nested inside the top-level exception you are catching at the UI level. Can you see if there's an inner exception with more detail?

[sylum]

Hi Rocky,

I think a find something. Following your advice, I have tried to see what happens into the HttpProxy class.
Actually, the method CallViaHttpClient is called without exception, but next when the DataPortalProxy try to Deserialize the data, the response came with an ErrorData (Unable to read beyond the end of the stream)

According the plateform (Win or Droid), I have noticed the serialized data seems different

Below Windows (working)

Below Droid (not working)

I dont know if it's meaningful but if I'm forcing the dataportal to be isSync = True then the Droid works.

Thx a lot for your help.

[CROprogrammer]

Hi, I'm facing the same issue and I'm curious to know where shoud 'isSync = True' be put?

[CROprogrammer]

I've tried changing isSync to be True always but I'm still getting "Unable to read beyond the end of the stream." exception. I'm using CSLA 6.2.2 and Xamarin.
This exception does not occur when using AppServer & MVC or AppServer & WPF, only AppServer & Xamarin.

Exception occurs here:

   at System.IO.BinaryReader.InternalRead(Int32 numBytes)
   at Csla.Serialization.Mobile.CslaBinaryReader.Read(Stream serializationStream)
   at Csla.Serialization.Mobile.MobileFormatter.Deserialize(Stream serializationStream)
   at Csla.Server.Hosts.HttpPortalController.InvokePortal(String operation, Stream requestStream, Stream responseStream)

[sylum]

When debugging csla-6.2.2, I have spoted this point into DataPortalProxy.cs csla class.
By forcing the IsSync to True for the CallDataPortalServer method like below, the (maui) Android N-tiers works.

[RolandoTonin]

I have the same problem. My Maui Android client App, calling an App Service on Azure throws the exception "Csla.DataPortalException: Unable to read beyond the end of the stream" every time I use FetchAsync or ExecuteAsync(). If instead I use Fetch() and Execute() everything works fine.
Both client and server side have CSLA 7.0.0 installed but the same problem I encountered with CSLA 6.2.2.
In the App Server's Program class I use:

builder.Services.AddCsla(o => o
.AddAspNetCore()
.DataPortal(dpo => dpo
.EnableSecurityPrincipalFlowFromClient()
.AddServerSideDataPortal()
));

while client side (MauiProgram class):
mauiAppBuilder.Services.AddCsla(o => o
.RegisterContextManager<Csla.Xaml.ApplicationContextManager>()
.DataPortal(dp => dp
.EnableSecurityPrincipalFlowFromClient()
.UseHttpProxy(hp =>
{
hp.DataPortalUrl = "https://XXX.azurewebsites.net/api/dataportal";
}
)));
if client side i built it for windows machine it works correctly. I experimented with the same code with a WPF App client and it works also fine.
The problem is with Android Emulator and also with a Samsung Android phone.
Thanks a lot for any suggestion
Rolando

[RolandoTonin]

hy all,
Have any of you had the same problem and found a solution?

thanks a lot
Rolando

[rockfordlhotka]

I have finally had time to replicate this issue so I can work on a solution. Issue tracking this is #3791

[rockfordlhotka]

I have a workaround at least.

If you configure the client and data portal endpoint (http portal controller) for UseTextSerialization = true then the data portal operates correctly.

I don't know yet if this is a CSLA bug or a limitation of Android (or MAUI?). The whole reason UseTextSerialization was added in the first place is because early versions of Blazor wasm couldn't do binary data transfers.

[kobi-shanti]

I can confirm I've experienced the same bug using Xamarin, so I don't believe it is restricted to MAUI.

[rockfordlhotka]

Maybe it has to do with Android?

At least we have a reasonable workaround.

[sylum]

Thx a lot, the workaround works perfectly.

[rockfordlhotka]

We now have a better workaround that allows you to continue to use the binary data transfer (which is more efficient).

Leave the data portal configuration as normal, and change the configuration of the HttpClient service in MauiProgram.cs:

  builder.Services.AddScoped<HttpClient>((p) => new HttpClient(new SocketsHttpHandler()));

https://github.com/MarimerLLC/csla/blob/main/docs/Upgrading%20to%20CSLA%208.md#maui-android