Blazor Web App Static Proxy Endpoint Generates Incorrectly #10097

4 Answer(s)

• 

  0

  AI-Bot created 22 days ago

  Support Team ABP Agent

  1. Solution

  • Root cause

    • Your method receives a file using ABP’s stream-friendly DTO (CreateFileInputWithStream with an IRemoteStreamContent/File field). Such endpoints must be exposed as multipart/form-data. In a Blazor Web App (WASM + Server host) solution, when you enable Static C# Proxies on the Blazor Server host, the Auto API/Swagger for the Server app can incorrectly describe that action as application/json and omit multipart/form-data. Calls made through the static proxy then send JSON, resulting in 415 Unsupported Media Type.

  • Fix: force the correct content type on the action and let Swagger describe it properly

    • Add FromForm to the file/stream input model argument so model binding selects multipart/form-data.
    • Add explicit Consumes attribute to the action to declare multipart/form-data.
    • Ensure your file input type in the DTO is IRemoteStreamContent (or IFormFile) so ABP’s formatter kicks in.

    Example:

  using Microsoft.AspNetCore.Mvc;
    using Volo.Abp.Content;
  
    public class CreateFileInputWithStream
    {
        public string Name { get; set; }
        public IRemoteStreamContent File { get; set; }
        public ExtraPropertyDictionary ExtraProperties { get; set; }
    }
  
    [ApiController]
    [Route("api/app/organization-attachment")]
    public class OrganizationAttachmentController : ControllerBase
    {
        [HttpPost]
        [Consumes("multipart/form-data")]
        public async Task<AttachmentDto> CreateAsync(
            [FromQuery] Guid attachmentTypeId,
            [FromQuery] Guid entityId,
            [FromForm] CreateFileInputWithStream inputWithStream,
            [FromQuery] bool replaceByAttachmentType = false,
            [FromQuery] bool autoSave = false)
        {
            // call your service method here
            // return await _appService.CreateAsync(...);
            throw new NotImplementedException();
        }
    }
  

  Notes:

  • If you’re using ABP Auto API Controllers (recommended), you don’t have to manually define the controller; you can annotate your application service method similarly:

  [Consumes("multipart/form-data")]
      public virtual Task<TAttachmentDto> CreateAsync(
          Guid attachmentTypeId,
          TEntityKey entityId,
          [FromForm] CreateFileInputWithStream inputWithStream,
          bool replaceByAttachmentType = false,
          bool autoSave = false)
      { ... }
  

  • After adding Consumes + FromForm, re-run and check the Blazor Server Swagger. It should now show a multipart/form-data body with a binary File field, matching your HttpApi.Host/API swagger.

  • Ensure the WASM static proxy posts FormData

    • The generated WASM proxy for a parameter typed as IRemoteStreamContent or a DTO containing it posts multipart/form-data automatically. If you have a custom call, use FormData:

  // In Blazor WASM
      var form = new MultipartFormDataContent();
      form.Add(new StringContent(attachmentTypeId.ToString()), "attachmentTypeId");
      form.Add(new StringContent(entityId.ToString()), "entityId");
      form.Add(new StringContent(input.Name), "inputWithStream.Name");
      form.Add(new StreamContent(fileStream) { Headers = { ContentType = new MediaTypeHeaderValue(fileContentType) }}, "inputWithStream.File", fileName);
      // plus ExtraProperties if needed
  

  • Prefer using the generated C# static proxy method for the service interface; once Swagger describes multipart/form-data correctly, the proxy will send the right content type and 415 will disappear.

  • If the Blazor Server host still shows the wrong content type

    • Clear and re-generate static proxies and swagger:
      • Stop the solution, delete bin/obj, rebuild.
      • Ensure you don’t have an outdated generated proxy/contract assembly altering ApiExplorer.
    • If you host client proxies on the Server app, make sure your HttpApi project references the Application.Contracts and your Blazor Server project references the HttpApi.Client (not Contracts) for consuming remote APIs.
    • Avoid custom ApiExplorer/Swagger filters that override request body content types.

  2. Sources

  • Auto API Controllers and content negotiation for streams:
    • https://docs.abp.io/en/abp/latest/API/Auto-API-Controllers
  • ABP repository reference for IRemoteStreamContent usage and tests:
    • https://github.com/abpframework/abp

  ---

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• 

  0

  maliming created 22 days ago

  Support Team Fullstack Developer

  hi

  Can you share a new template project with your code?

  liming.ma@volosoft.com

  Thanks.

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• 

  0

  ddelamare created 21 days ago

  I built out a new template with the affected service classes and I was able to reproduce the issue of the controller methods not generating with a multipart/form data input option. However, I was able to fix it by adding this to the module startup config.

  Configure<AbpAspNetCoreMvcOptions>(options => { options.ConventionalControllers.FormBodyBindingIgnoredTypes.Add(typeof(CreateFileInputWithStream)); });

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• 

  0

  maliming created 21 days ago

  Support Team Fullstack Developer

  Great 👍

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