javascript - Splitting a file before upload?

Question

On a webpage, is it possible to split large files into chunks before the file is uploaded to the server? For example, split a 10MB file into 1MB chunks, and upload one chunk at a time while showing a progress bar?

It sounds like JavaScript doesn't have any file manipulation abilities, but what about Flash and Java applets?

This would need to work in IE6+, Firefox and Chrome. Update: forgot to mention that (a) we are using Grails and (b) this needs to run over https.

Answer 1

You can try Plupload. It can be configured to check whatever runtime is available on users side, be it - Flash, Silverlight, HTML5, Gears, etc, and use whichever satisfies required features first. Among other things it supports image resizing (on users side, preserving EXIF data(!)), stream and multipart upload, and chunking. Files can be chunked on users side, and sent to a server-side handler chunk-by-chunk (requires some additional care on server), so that big files can be uploaded to a server having max filesize limit set to a value much lower then their size, for example. And more.

Some runtimes support https I believe, some need testing. Anyway, developers on there are quite responsive these days. So you might at least try ;)