Blazoe WebApp Request Validation Failing #9998

2 Answer(s)

• 

  0

  AI-Bot created 10 hours ago

  Support Team ABP Agent

  1. For the issue with [DisableValidation] and 400 errors in WebAssembly (WASM) mode:

     • In Blazor WASM (especially with prerendering or InteractiveAuto), validation may occur on the client before the request reaches your API. ABP's generated proxies and validation pipeline can behave differently between server and WASM modes. If you want to ensure validation only happens on the server, avoid using client-side proxies for these calls, or use direct HTTP requests (e.g., via HttpClient) to your API endpoints. This bypasses the client-side validation layer and ensures the [DisableValidation] attribute is respected server-side.
     • There is no built-in ABP option to globally disable client-side validation for all proxies in WASM mode. You must either avoid using the generated proxy for that endpoint or customize the proxy/service code to skip validation.

  2. For the file upload API returning "Unsupported Media Type" in WASM mode:

     • This error typically occurs if the request's Content-Type does not match what the API expects (e.g., multipart/form-data for file uploads). In Blazor WASM, ensure you are using IBrowserFile and MultipartFormDataContent when sending files, and that your API action is decorated with [Consumes("multipart/form-data")].
     • If you are using ABP's auto-generated proxies, they may not handle file uploads correctly in WASM mode. In such cases, use HttpClient directly to construct and send the multipart request.

  Example for file upload in Blazor WASM:

  var content = new MultipartFormDataContent();
  content.Add(new StreamContent(file.OpenReadStream()), "File", file.Name);
  await httpClient.PostAsync("api/your-endpoint", content);
  

  And in your API controller:

  [HttpPost]
  [Consumes("multipart/form-data")]
  public async Task<IActionResult> Upload([FromForm] YourFileUploadDto input)
  {
      // handle file
  }
  

  Summary:

  • For [DisableValidation], use direct HTTP calls for endpoints where you want to avoid client-side validation.
  • For file uploads, use HttpClient with MultipartFormDataContent and ensure your API expects multipart/form-data.

  Sources:

  • Blazor Error Handling
  • Blazor WASM Prerendering & Known Issues

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• 

  0

  ddelamare created 10 hours ago

  I am not able to call the API directly since the new WebApp model applies credentials in the Blazor server before forwarding to the API. Having to maintain custom http client calls is also not acceptable overhead.

  I can see the requests being fired so the validation is not happening in the brower.

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