Unity WebGL does not Post to Azure Function app: form already read

I'm on Unity 2019.3.0f3 or 2019.3.0f5 or 2019.3.9 and Azure Functions V3.

I can't get the post into variables in the Function app: the Function app throws http 500 with "Unexpected end of Stream, the content may have already been read by another component.". So when webgl project is run on browser, chrome shows 500 internal error; firefox doesn't show the data on console but neither shows the error but you can see http 500 error with Fiddler.

Project runs on Editor and Postman.

Function app is now running and publicly available at https://unitywebglbugtest.azurewebsites.net/api/TestBug

Code (CSharp):

1. public class Function1
2.     {
3.         [FunctionName("TestBug")]
4.         public async Task<HttpResponseMessage>
5.  
6.     TestBug([HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req, ILogger log)
7.             {
8.                 string myUsername = Convert.ToString(req.Form["clientusername"]);
9.                 return new HttpResponseMessage(HttpStatusCode.OK)
10.                 {
11.                     Content = new StringContent($"Result: {myUsername}", Encoding.UTF8, "text/plain")
12.                 };
13.             }
14.     }

Unity Webgl built and hosted project you can run to test: https://webglappbugtest.azurewebsites.net

Sample Unity webgl submit form:

Code (CSharp):

1. List<IMultipartFormSection> formData = new List<IMultipartFormSection>();
2.     string stringTest = "hello@gmail.com";
3.     formData.Add(new MultipartFormDataSection("clientusername", stringTest, "text/plain"));
4.     UnityWebRequest www = UnityWebRequest.Post("https://unitywebglbugtest.azurewebsites.net/api/TestBug", formData);
5.     Debug.Log("Now sending form " + stringTest);
6.     yield return www.SendWebRequest();
7.     string queryResult = www.downloadHandler.text;
8.     Debug.Log(queryResult);

 

I think that you are affected by this bug here : https://forum.unity.com/threads/mangled-post-requests-with-unitywebrequest-on-2018-4-x.858925/

Your link https://webglappbugtest.azurewebsites.net/ work perfectly for me and i get :

Code (CSharp):

1.  
2. Now sending form hello@gmail.com
3. (Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 35)
4.  
5. Result: hello@gmail.com
6. (Filename: ./Runtime/Export/Debug/Debug.bindings.h Line: 35)
7.  

Try GET instead of POST and i'm 100% sure that your code will work for you (as affected user).

Unity team do not answer for the bug https://forum.unity.com/threads/mangled-post-requests-with-unitywebrequest-on-2018-4-x.858925 ...........

 

Thanks a bunch for sharing some light @roka ! It then seems like Azure's system suffers from this issue cos I'm seeing this with both chrome/firefox browsers when the data is sent to azure's functions.

Unfortunately @Kumo-Kairo 's decompressed/gzip solution doesn't work for me , probably cos i'm on 2019.3 version.

I'll ask a question in your main thread for this issue to keep things together.

Cheers!

 

It's not your Azure's system that have a problem, it's an issue from your computer/system because your project work perfectly fine for me. Do not ask me why, i don't know.
Also, if unity patch this bug, nobody will be affected anymore.

 

For the GET,

https://docs.unity3d.com/ScriptReference/Networking.UnityWebRequest.Get.html

With uri that will be something like "https://unitywebglbugtest.azurewebsites.net/api/TestBug?clientusername=" + stringTest

 

Got'cha @roka thanks a bunch !

Though I really dislike the idea of having no option but using query params particularly after Zoom's hack cos all can easily see these

 

you're right again @roka , i tested this website on a mac book pro and works just fine. It's on my windows 10 machine it fails.

 

This is very weird. Just tested it again today and it works just fine ... I made no changes to it, it just works. Fiddler doesn't show garbage anymore ... no clue

 

It was not the code your problem , but your system environment , maybe you have updated your windows, web browser ect .... and it do the trick.