code for upload file size validation

[heavenite]

Is there any way to validate the size of the file before uploading it throgu uploadItem? I know the first time the server knows the size of the file is when upload has already started. So, I am trying to pass the file name to
JSNI to check the file size before upload. Is there any code sample could be applied w/ smartgwt ?

[Isomorphic]

Use dataSourceField.maxFileSize. This aborts the upload as soon as it's known that the file is too large.