OnClientFileSelected filename validation

[Yuly]

Please bear with me, as this is my first post.

I am trying to do a clientside validation on filename expression. I do not want to have :, /, %, etc in my file names. How do you guys do that?

[Ivan Danchev]

Hello Yuly,

You can prevent the upload of files with names containing special characters, "/%" for example, by subscribing to the AsyncUpload's OnClientFileUploading event and cancelling the event in case the filename contains a forbidden character:

function OnClientFileUploading(sender, args) {
    var fileName = args.get_fileName();

    if (!isValid(fileName)) {
        args.set_cancel(true);
    }
}

function isValid(str) {
    return !/[~`!#$%\^&*+=\-\[\]\\';,/{}|\\":<>\?]/g.test(str);
}

The event will fire for every selected file, so in case you are selecting multiple files (MultipleFileSelection="Automatic") the event will be cancelled only for those with special characters in their name. 

Regards,
Ivan Danchev
Telerik by Progress