WASM / Xamarin Forms - HttpClient doesn't work #146

zbigniew-gajewski · 2018-04-25T19:29:35Z

Ooui, Ooui.Wasm, Ooui.Forms 0.10.222.

The code:

namespace OouiTestXamlApp
{
    using Ooui;
    using System.Net.Http;
    using Xamarin.Forms;

    class Program
    {
        static void Main(string[] args)
        {
            Forms.Init();
            var page = new MainPage();
            UI.Publish("/", page.GetOouiElement());
            GetData();
        }

        public static async void GetData()
        {
            var httpClient = new HttpClient();
            var response = await httpClient.GetAsync("http://www.google.com");
        }
    }
}

Browser console shows error:

System.PlatformNotSupportedException: Operation is not supported on this platform.

The whole error message:

GET http://localhost:52222/ [HTTP/1.1 200 OK 3ms]
GET https://ajax.aspnetcdn.com/ajax/bootstrap/3.3.7/css/bootstrap.min.css [HTTP/2.0 304 Not Modified 52ms]
GET http://localhost:52222/ooui.js [HTTP/1.1 200 OK 19ms]
GET http://localhost:52222/mono.js [HTTP/1.1 304 Not Modified 1ms]
GET https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css [HTTP/2.0 304 Not Modified 55ms]
mono.js:1:34855
Unhandled Exception:
mono.js:1:34855
System.PlatformNotSupportedException: Operation is not supported on this platform.
mono.js:1:34855
  at System.Net.WebProxy.CreateDefaultProxy () <0x2836738 + 0x00004> in <c5e34d81ad314f7ab9644fbd9cbc69b1>:0 
mono.js:1:34855
  at System.Net.Configuration.DefaultProxySectionInternal.GetSystemWebProxy () <0x28365e0 + 0x00000> in <c5e34d81ad314f7ab9644fbd9cbc69b1>:0 
mono.js:1:34855
  at System.Net.Configuration.DefaultProxySectionInternal.GetDefaultProxy_UsingOldMonoCode () <0x2836498 + 0x00000> in <c5e34d81ad314f7ab9644fbd9cbc69b1>:0 
mono.js:1:34855
  at System.Net.Configuration.DefaultProxySectionInternal.GetSection () <0x28362e0 + 0x00022> in <c5e34d81ad314f7ab9644fbd9cbc69b1>:0 
mono.js:1:34855
  at System.Net.WebRequest.get_InternalDefaultWebProxy () <0x2835f28 + 0x0002c> in <c5e34d81ad314f7ab9644fbd9cbc69b1>:0 
mono.js:1:34855
  at System.Net.HttpWebRequest..ctor (System.Uri uri) <0x28185e0 + 0x000d2> in <c5e34d81ad314f7ab9644fbd9cbc69b1>:0 
mono.js:1:34855
  at System.Net.Http.HttpClientHandler.CreateWebRequest (System.Net.Http.HttpRequestMessage request) <0x2817bf8 + 0x00016> in <bb3c97b3061e4bd2ab2156520b1e6fdd>:0 
mono.js:1:34855
  at System.Net.Http.HttpClientHandler+<SendAsync>d__64.MoveNext () <0x2827030 + 0x00076> in <bb3c97b3061e4bd2ab2156520b1e6fdd>:0 
mono.js:1:34855
--- End of stack trace from previous location where exception was thrown ---
mono.js:1:34855
  at System.Net.Http.HttpClient+<SendAsyncWorker>d__47.MoveNext () <0x27b38e8 + 0x0017e> in <bb3c97b3061e4bd2ab2156520b1e6fdd>:0 
mono.js:1:34855
--- End of stack trace from previous location where exception was thrown ---
mono.js:1:34855
  at OouiTestXamlApp.Program+<GetData>d__1.MoveNext () <0x275a920 + 0x000e0> in <81d99247780f47eba866b9de0917b7d4>:0 
mono.js:1:34855
--- End of stack trace from previous location where exception was thrown ---
mono.js:1:34855
  at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_1 (System.Object state) <0x2d8c3f8 + 0x00014> in <b3fce0803fba480fae38154d157eea73>:0 
mono.js:1:34855
  at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context (System.Object state) <0x2d8c270 + 0x00026> in <b3fce0803fba480fae38154d157eea73>:0 
mono.js:1:34855
  at System.Threading.ExecutionContext.RunInternal (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) <0x2d73a28 + 0x000f0> in <b3fce0803fba480fae38154d157eea73>:0 
mono.js:1:34855
  at System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) <0x2d736c8 + 0x00020> in <b3fce0803fba480fae38154d157eea73>:0 
mono.js:1:34855
  at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem () <0x2d8c1f0 + 0x00046> in <b3fce0803fba480fae38154d157eea73>:0 
mono.js:1:34855
  at System.Threading.ThreadPoolWorkQueue.Dispatch () <0x2d6e780 + 0x000f4> in <b3fce0803fba480fae38154d157eea73>:0 
mono.js:1:34855
  at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback () <0x2d6e370 + 0x00000> in <b3fce0803fba480fae38154d157eea73>:0 
mono.js:1:34855
[ERROR] FATAL UNHANDLED EXCEPTION: System.PlatformNotSupportedException: Operation is not supported on this platform.
mono.js:1:34855
  at System.Net.WebProxy.CreateDefaultProxy () <0x2836738 + 0x00004> in <c5e34d81ad314f7ab9644fbd9cbc69b1>:0 
mono.js:1:34855
  at System.Net.Configuration.DefaultProxySectionInternal.GetSystemWebProxy () <0x28365e0 + 0x00000> in <c5e34d81ad314f7ab9644fbd9cbc69b1>:0 
mono.js:1:34855
  at System.Net.Configuration.DefaultProxySectionInternal.GetDefaultProxy_UsingOldMonoCode () <0x2836498 + 0x00000> in <c5e34d81ad314f7ab9644fbd9cbc69b1>:0 
mono.js:1:34855
  at System.Net.Configuration.DefaultProxySectionInternal.GetSection () <0x28362e0 + 0x00022> in <c5e34d81ad314f7ab9644fbd9cbc69b1>:0 
mono.js:1:34855
  at System.Net.WebRequest.get_InternalDefaultWebProxy () <0x2835f28 + 0x0002c> in <c5e34d81ad314f7ab9644fbd9cbc69b1>:0 
mono.js:1:34855
  at System.Net.HttpWebRequest..ctor (System.Uri uri) <0x28185e0 + 0x000d2> in <c5e34d81ad314f7ab9644fbd9cbc69b1>:0 
mono.js:1:34855
  at System.Net.Http.HttpClientHandler.CreateWebRequest (System.Net.Http.HttpRequestMessage request) <0x2817bf8 + 0x00016> in <bb3c97b3061e4bd2ab2156520b1e6fdd>:0 
mono.js:1:34855
  at System.Net.Http.HttpClientHandler+<SendAsync>d__64.MoveNext () <0x2827030 + 0x00076> in <bb3c97b3061e4bd2ab2156520b1e6fdd>:0 
mono.js:1:34855
--- End of stack trace from previous location where exception was thrown ---
mono.js:1:34855
  at System.Net.Http.HttpClient+<SendAsyncWorker>d__47.MoveNext () <0x27b38e8 + 0x0017e> in <bb3c97b3061e4bd2ab2156520b1e6fdd>:0 
mono.js:1:34855
--- End of stack trace from previous location where exception was thrown ---
mono.js:1:34855
  at OouiTestXamlApp.Program+<GetData>d__1.MoveNext () <0x275a920 + 0x000e0> in <81d99247780f47eba866b9de0917b7d4>:0 
mono.js:1:34855
--- End of stack trace from previous location where exception was thrown ---
mono.js:1:34855
  at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__6_1 (System.Object state) <0x2d8c3f8 + 0x00014> in <b3fce0803fba480fae38154d157eea73>:0 
mono.js:1:34855
  at System.Threading.QueueUserWorkItemCallback.WaitCallback_Context (System.Object state) <0x2d8c270 + 0x00026> in <b3fce0803fba480fae38154d157eea73>:0 
mono.js:1:34855
  at System.Threading.ExecutionContext.RunInternal (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) <0x2d73a28 + 0x000f0> in <b3fce0803fba480fae38154d157eea73>:0 
mono.js:1:34855
  at System.Threading.ExecutionContext.Run (System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, System.Object state, System.Boolean preserveSyncCtx) <0x2d736c8 + 0x00020> in <b3fce0803fba480fae38154d157eea73>:0 
mono.js:1:34855
  at System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem () <0x2d8c1f0 + 0x00046> in <b3fce0803fba480fae38154d157eea73>:0 
mono.js:1:34855
  at System.Threading.ThreadPoolWorkQueue.Dispatch () <0x2d6e780 + 0x000f4> in <b3fce0803fba480fae38154d157eea73>:0 
mono.js:1:34855
  at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback () <0x2d6e370 + 0x00000> in <b3fce0803fba480fae38154d157eea73>:0 
mono.js:1:34855
ExitStatus: Program terminated with exit(255)
mono.js:1:345822

The text was updated successfully, but these errors were encountered:

praeclarum · 2018-04-25T23:48:38Z

Unfortunately this might be a mono limitation. I will ask them what the best way to do HTTP is.

zbigniew-gajewski · 2018-04-26T18:16:27Z

Thanks. No worries, I am just testing your library (I am interested in Ooui.Wasm/Forms only) trying to understand the concept in comparison to Silverlight (and have a lot of fun).

Of course 'data access' is necessary, especially HttpClient, which is probably used by another library I am testing - Breeze.Sharp ported to .Net Standard 2.0 ('probably', because I am getting the same error using this library).

BTW, I have found this thread: xaml-Standard - people really miss something similar to Silverlight, which (imho) is your great Ooui.Wasm/Forms lib.

zbigniew-gajewski · 2018-04-28T07:41:19Z

I have noticed that mono has published a new release 5.12.0 Preview (5.12.0.223) where some significant changes have been made which might affect HttpClient issues (Class Libraries section).

Would it be possible to use this version of mono in the next release of ooui (just to check whether it would help to make HttpClient working)?

D-R-R · 2018-05-09T21:40:36Z

I missed my chance to catch you after the Forms 3.0 talk at Build to make sure I understand this correctly now that the missing Mono forwarders from #96 aren't an issue 😁, but do you think it may be necessary to do what Blazor did and write a custom HttpMessageHandler that calls fetch via interop to get HttpClient working?

https://github.com/aspnet/Blazor/blob/dev/src/Microsoft.AspNetCore.Blazor.Browser/Http/BrowserHttpMessageHandler.cs

https://github.com/aspnet/Blazor/blob/dev/src/Microsoft.AspNetCore.Blazor.Browser.JS/src/Services/Http.ts

davidlsharp1 · 2018-06-07T21:04:15Z

@zbigniew-gajewski I think I'm following your same path because I am hitting this error now too. :) This is a fun framework and not the end of the world but HttpClient or something similar would be really nice.

zbigniew-gajewski · 2018-06-09T11:50:34Z

@davidlsharp1 - indeed fun framework, especially for Silverlight addict :) . HttpClient is a must, but as @praeclarum pointed out this is mono/Wasm problem, not Ooui. I am waiting for the next Ooui.Wasm with new mono version included. Another 'nice thing' would be UI controls with mouse support (as important as data access). Fortunately companies like Telerik/Progress is taking it into account: xamarin-forms-on-the-web (user voice page).

davidlsharp1 · 2018-06-09T16:59:26Z

That's a great article with props to Frank. Can somebody help me understand the mono problem with HttpClient? Is it specifically a wasm problem?

seguso · 2019-02-02T19:04:02Z

Any updates on this? We are getting PlatformNotSupportedException when doing a simple HttpClient.GetAsync().
It's kind of a showstopper for us.

F-Goncalves · 2021-07-26T08:20:03Z

I am wondering if this has been fixed or is supposed to be fixed at all?
It would be nice to be able to make http requests.

praeclarum · 2021-08-04T18:08:37Z

Yeah, the updated WASM should have HTTP support. I'll try to get that update PR in...

praeclarum added the question label Apr 25, 2018

zbigniew-gajewski closed this as completed Feb 3, 2019

F-Goncalves mentioned this issue Jul 26, 2021

Update WASM Support #241

Open

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

WASM / Xamarin Forms - HttpClient doesn't work #146

WASM / Xamarin Forms - HttpClient doesn't work #146

zbigniew-gajewski commented Apr 25, 2018

praeclarum commented Apr 25, 2018

zbigniew-gajewski commented Apr 26, 2018 •

edited

Loading

zbigniew-gajewski commented Apr 28, 2018

D-R-R commented May 9, 2018

davidlsharp1 commented Jun 7, 2018

zbigniew-gajewski commented Jun 9, 2018 •

edited

Loading

davidlsharp1 commented Jun 9, 2018

seguso commented Feb 2, 2019

F-Goncalves commented Jul 26, 2021

praeclarum commented Aug 4, 2021

WASM / Xamarin Forms - HttpClient doesn't work #146

WASM / Xamarin Forms - HttpClient doesn't work #146

Comments

zbigniew-gajewski commented Apr 25, 2018

praeclarum commented Apr 25, 2018

zbigniew-gajewski commented Apr 26, 2018 • edited Loading

zbigniew-gajewski commented Apr 28, 2018

D-R-R commented May 9, 2018

davidlsharp1 commented Jun 7, 2018

zbigniew-gajewski commented Jun 9, 2018 • edited Loading

davidlsharp1 commented Jun 9, 2018

seguso commented Feb 2, 2019

F-Goncalves commented Jul 26, 2021

praeclarum commented Aug 4, 2021

zbigniew-gajewski commented Apr 26, 2018 •

edited

Loading

zbigniew-gajewski commented Jun 9, 2018 •

edited

Loading