Is there a way to check if the request is coming from Browse for media files

Browse for media files

Or is it coming upload file or upload files

Upload file or files

I have code to check upload image size

public class ImageSizeCheck : UploadProcessor
        public List<string> RestrictedExtensions { get; set; }

        public ImageSizeCheck()
            RestrictedExtensions = new List<string>();

        public void Process(UploadArgs args)
            Assert.ArgumentNotNull((object)args, "args");
            if (args.Destination == UploadDestination.File)

            foreach (string index in args.Files)
                HttpPostedFile file = args.Files[index];
                if (!string.IsNullOrEmpty(file.FileName) && IsRestrictedExtension(file.FileName))
                    if ((long)file.ContentLength > MaxImageSizeInDatabase)
                        String message = string.Format("The image {0} can not be uploaded. The maximum size should be {1}.", file.FileName, MainUtil.FormatSize(MaxImageSizeInDatabase));
                        args.ErrorText = message;
                        Log.Warn(args.ErrorText, this);
                        message = "\"" + message + "\"";
                        string str = "<script>alert(" + message + ")</script>";

        private bool IsRestrictedExtension(string filename)
            return RestrictedExtensions.Exists(restrictedExtension => string.Equals(restrictedExtension, Path.GetExtension(filename), StringComparison.CurrentCultureIgnoreCase));

        public static long MaxImageSizeInDatabase
                return Sitecore.Configuration.Settings.GetLongSetting("Media.MaxImageSizeInDatabase", 524288000L);

The alert is working for UploadFile or UploadFiles but it is giving error for Browse for media files.

SyntaxError: Unexpected token < in JSON at position 0   


If I find that if the request is coming from Browse for media files then I can skip HttpContext.Current.Response.Write(str);

Any suggestion would be appreciated. Thanks in advance.

1 Answer 1


It seems to me that the message should display meaningful message rather than unexpected json token message.

Could you please perform the following steps to make it display the meaningful message:

Open the Uploader.js via <sitecore_instance>\sitecore\shell\client\Business Component Library\Layouts\Renderings\Forms\Uploader Find the following upload method:

upload: function () 

Replace the above upload method code with the following:

upload: function () { var that = this; this.startUploadTimer(this.datas); this.updateUploadInfo(true, true);

  //for each files - do the upload
  _.each(this.datas, function (data) {
    data.submit().error(function (jqXHR, textStatus, errorThrown) {
      if (jqXHR.status === 401) {
      // Triggers error on each model that had an abort
      if (jqXHR.responseText.indexOf('errorItems') != -1) {
        var errordata = jqXHR.responseText.split('</html>');
        var parsedJson = JSON.parse(errordata[1]);
        _.each(parsedJson.errorItems[1].Message, function (error) {
          error.id = data.__id;
        var errors = [{ Message: parsedJson.errorItems[1].Message }];
        that.app.trigger("sc-error", errors);
        that.app.trigger("upload-error", { id: data.__id, errors: parsedJson.errorItems[1].Message });

        return undefined;
        if (errorThrown === "abort") {
          that.app.trigger("upload-error", { id: data.__id });
        } else {
          var errors = [{ Message: errorThrown }];
          that.app.trigger("sc-error", errors);
          that.app.trigger("upload-error", { id: data.__id, errors: errors });

After you perform the above steps, you should be able to see the meaningful message display on the upload media about why the media item is not uploaded successfully.

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