Upload in Synchronous Mode File Type Validation

Environment

Product	Progress® Kendo UI® Upload for jQuery
Operating System	All
Browser	All
Preferred Language	JavaScript

Description

How can I validate the file selected in the Upload by file type (extension), when synchronous mode is used?

Solution

When the Upload is configured to use synchronous mode the file type validation can be done with the Kendo UI Validator as demonstrated below.

    <form method="post" action="https://demos.telerik.com/kendo-ui/upload/submit">
        <div class="demo-section k-content">
            <input name="files" id="files" type="file" aria-label="files" />
            <p style="padding-top: 1em; text-align: right">
                <button type="submit" class="k-button k-primary">Submit</button>
            </p>
        </div>
    </form>
    <script>
        $(document).ready(function() {
            $("#files").kendoUpload({
				validation: {
					allowedExtensions: [".jpg"],
				}
            });
        });

		var validatable = $("form").kendoValidator({
			rules: {
				upload: function(input) {
					if (input[0].type == "file") {
						return (input.closest(".k-upload").find(".k-file").length > 0 && input.closest(".k-upload").find(".k-file-invalid").length == 0);
					}
					return true;
				}
			}
		}).data("kendoValidator");
    </script>
	<style>  
	.k-upload-button .k-invalid-msg {
		display: none !important;
	}
	</style>