Problems with my custom validation in Upload

[SANDRO]

Hello, I hope you are well.

I hope you can help me with this problem I have.

I am using the Kendo UI for JQuery Upload.

What I require is to upload an entire folder of TXT files, but I have a routine that validates that the name and content meet certain rules.

I apply these rules within the foreach loop (var file in files), because what is required is that if the file is valid it shows a text that it is valid, otherwise it shows a text that is not valid and for both options to continue processing the next file.

But by marking that file as erroneous, the controller is exited and the view is returned, thus leaving the processing of the rest of the files incomplete.

I share the code of the view and the controller, hoping you can give me some light.

View Code:

<div class="centered">
    @using Kendo.Mvc.UI
    <div>
        <div class="demo-section">
            @(Html.Kendo().Upload()
                .Name("files")
                .Async(a => a
                    .Save("ChunkSave", "Upload")
                    .Remove("Chunk_Upload_Remove", "Upload")
                    .AutoUpload(true)
                    .ChunkSize(11000)

                )
                .Multiple(true) // Enable multiple file selection
                    .Directory(true)
                    .DirectoryDrop(true)
                .Validation(validation =>
                {
                    //validation.MaxFileSize(20000000);
                })
                .Events(events =>
                {
                    events.Upload("onUpload");
                    events.Success("onUploadSuccess");
                    events.Error("onUploadError");
                    events.Select("onSelect");
                })
                .Messages(messages =>
                {
                    messages
                        .Select("Seleccionar archivos")
                        .DropFilesHere("Suelta archivos aquí para cargarlos")
                        .Remove("Eliminar")
                        .Retry("Reintentar")
                        .StatusFailed("Error")
                        .StatusUploaded("Terminado")
                        .StatusUploading("Cargando")
                        .UploadSelectedFiles("Cargar archivos")
                        .UploadFail("Error al procesar el archivo.")
                        .HeaderStatusUploaded("Terminado");
                })

            )
        </div>
    </div>
</div>

 

Controller Code:

public async Task<ActionResult> ChunkSave(IEnumerable<IFormFile> files, string metaData, string cve)
{

    int status = 0;
    DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(ChunkMetaData));


    MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(metaData));
    ChunkMetaData? somemetaData = serializer.ReadObject(ms) as ChunkMetaData;
    string path = String.Empty;

    if (files != null)
    {
        foreach (var file in files)
        {
            cap_dbt controller = new cap_dbt(_context);
            controller.ProcessFile(file, somemetaData.FileName, cve);
            status = controller.ProcessFile(file, somemetaData.FileName, cve);
            if (status == 1)
            {
                Upload(files, somemetaData.FileName);
            }
        }
    }


    if (somemetaData is null)
    {
        throw new Exception("No Metadata!");
    }

    Util.FileResult fileBlob = new Util.FileResult();
    fileBlob.uploaded = somemetaData.TotalChunks - 1 <= somemetaData.ChunkIndex;
    fileBlob.fileUid = somemetaData.UploadUid;
    fileBlob.warnings = Mensajes.msgLoadCsvWarning;
    fileBlob.message = "[" + somemetaData.FileName + "]\t";

    try
    {
        if (!fileBlob.uploaded)
        {
            fileBlob.message += "[ERROR]" + Mensajes.msgLoadCsvError;

            return StatusCode(500, fileBlob);
        }
        else if (status == -1)
        {
            fileBlob.uploaded = false;
            fileBlob.message += "[ERROR] " + Mensajes.msgLoadCsvError;
            throw new Exception(fileBlob.message); // <------- If I remove this line, it continues processing, but it no longer changes the file, it stays with the same name or empty.

        }

        if (fileBlob.warnings.Equals(""))
        {
            fileBlob.message += Mensajes.msgLoadCsvOk;
        }
    }

    catch (Exception ex)
    {
        Console.WriteLine(ex.ToString());
        return StatusCode(500, fileBlob);
    }
    finally
    {
        Mensajes.resetMsg();
    }

    return Json(fileBlob);
}

The following line was created to manipulate the Upload properties:
Util.FileResult fileBlob = new Util.FileResult();

I know what I can do if my file is not valid:
fileuid=""
success = false

But I see that if success is false it stops processing all the files and exits and goes to view.

[Mihaela]

Hi Sandro,

By default, the selected files are uploaded one after the other. For this reason, the uploading process stops when a specified file is invalid. When the Concurrent() option is enabled, the files will start to upload simultaneously, so the uploading process will not stop in case of invalid files:

 @(Html.Kendo().Upload()
                .Name("files")
                .Async(a => a
                    .Save("ChunkSave", "Upload")
                    .Remove("Chunk_Upload_Remove", "Upload")
                    .AutoUpload(true)
                    .ChunkSize(11000)
                    .Concurrent(true)
                )
                ...
)

Would you enable this option and let me know how the behavior changes at your end?

Regards,
Mihaela
Progress Telerik

[SANDRO]

Hello.

I tried the proposal that you indicated to me, but notice that it did not work for what is required.

I'll send you a screenshot and I'll explain.
It can be seen that the files are processed, but the messages that I indicated appear are not displayed. The following code in the view is where I specify the messages:

.Messages(messages =>
{
     messages
         .Select("Select files")
         .DropFilesHere("Drop files here to upload")
         .Remove("Remove")
         .Retry("Retry")
         .StatusFailed("Error")
         .StatusUploaded("Finished")
         .StatusUploading("Uploading")
         .UploadSelectedFiles("Upload files")
         .UploadFail("Error processing file.")
         .HeaderStatusUploaded("Finished");
})

It is also seen in the image that the upload process has not finished, since the blue bars are still active and the pause control is still active.

Looking forward to your comments.

[Mihaela]

Hi Sandro,

When a specified file is invalid, you can set the "uploaded" property to "false" and return the respective StatusCode and FileResult (similar to the previous condition that checks for !fileBlob.uploaded:

    try
    {
        if (!fileBlob.uploaded)
        {
            fileBlob.message += "[ERROR]" + Mensajes.msgLoadCsvError;

            return StatusCode(500, fileBlob);
        }
        else if (status == -1)
        {
            fileBlob.uploaded = false;
            fileBlob.message += "[ERROR] " + Mensajes.msgLoadCsvError;
            return StatusCode(500, fileBlob);
        }

        if (fileBlob.warnings.Equals(""))
        {
            fileBlob.message += Mensajes.msgLoadCsvOk;
        }
    }

    catch (Exception ex)
    {
        Console.WriteLine(ex.ToString());
        return StatusCode(500, fileBlob);
    }
    finally
    {
        Mensajes.resetMsg();
    }

    return Json(fileBlob);

I am attaching a runnable sample for your reference. 

Best,

Mihaela

[Ashapura Softech]

Common Problems:

• Validation not triggered:
  • Make sure your custom validation function is attached to the correct field in your form.
  • Verify if your form submission logic calls the validation function.
• Incorrect validation logic:
  • Double-check the logic in your custom validation function. Ensure it accurately checks the uploaded file for the criteria you defined (e.g., size, type, etc.).
• Errors not displayed:
  • If validation fails, ensure your code displays appropriate error messages to the user.
  • This might involve modifying your form handling logic to capture and display validation errors.
• File not accessible:
  • Verify that your code has access to the uploaded file object within your validation function.

Troubleshooting Tips:

1. Test with Simple Validation: Start with a basic validation like checking if a file is uploaded at all. This helps isolate issues with attaching the validation function or accessing the uploaded file.

2. Logging & Debugging: Add logging statements within your validation function to track the values of variables and the execution flow. This can help identify where the issue might be occurring.

3. Print Statements (for development): For quick checks during development, you can use temporary print statements to display the contents of the uploaded file object or validation results. This can provide immediate insights.

4. Check Framework Documentation: Refer to the documentation for the framework you're using (e.g., Django, Flask) for specific guidance on custom validation and accessing uploaded files.

5. Search Online Resources: Search online forums and communities related to your framework and custom file upload validation. You might find solutions or workarounds for specific problems encountered by others.