upload.progressFunction
Fires when the data about the progress of the upload is available. Upload Events.
Example
<div id="fileManager"></div>
<script>
    var baseUrl = "https://demos.telerik.com/service/v2/core/filemanager/";
    $("#fileManager").kendoFileManager({
        upload: {
            progress: function(e) {
                console.log("Upload progress: " + Math.round(e.percentComplete) + "%");
            }
        },
        dataSource: {
            transport: {
                read: {
                    method: "POST",
                    url: baseUrl + "Read"
                }
            }
        }
    });
</script>In this article