Filename, Error events and validation with synchronous mode

[Kerry]

Is it possible to have Filename, Error events and validation with synchronous mode? I have a form where i need the upload to happen on form submit for the additional information and would like these options. Is it possible? 

[Aleksandar]

Hello Kerry,

The built-in error event is available only when the Telerik UI for Asp.NET Core Upload is in asynchronous mode. If you would like to use it in synchronous mode I suggest reviewing the following posts for possible approach on handling HTML Form Data in ASP.NET Web API:

https://docs.microsoft.com/en-us/aspnet/web-api/overview/advanced/sending-html-form-data-part-1

https://docs.microsoft.com/en-us/aspnet/web-api/overview/advanced/sending-html-form-data-part-2

The synchronous mode does not prevent the use of File Validation. You could still initialize the Upload in the following manner to allow only the upload of images, for example, and apply image size validation:

<form method="post" action='@Url.Action("Submit")'>
    <div class="demo-section k-content">
        @(Html.Kendo().Upload()
         .Name("images")
         .Validation(validation => validation
             .AllowedExtensions(new string[] { ".gif", ".jpg", ".png" })
             .MaxFileSize(31457280)
             .MinFileSize(30720)
         )
        )
        <p style="padding-top: 1em; text-align: right">
            <button type="submit" class="k-button k-primary">Submit</button>
        </p>
    </div>
</form>

In the above example, the action method should expect a parameter named images. You can still obtain the information on file name as demonstrated in the Upload Basic Usage demo:

public ActionResult Submit(IEnumerable<IFormFile> images)
{
            IEnumerable<string> fileInfo = new List<string>();

            if (images != null)
            {
                fileInfo = GetFileInfo(images);
            }

            // custom logic on file saving/handling
}

private IEnumerable<string> GetFileInfo(IEnumerable<IFormFile> files)
        {
            List<string> fileInfo = new List<string>();

            foreach (var file in files)
            {
                var fileContent = ContentDispositionHeaderValue.Parse(file.ContentDisposition);
                var fileName = Path.GetFileName(fileContent.FileName.ToString().Trim('"'));

                fileInfo.Add(string.Format("{0} ({1} bytes)", fileName, file.Length));
            }

            return fileInfo;
        }

Regards,
Aleksandar
Progress Telerik