I am working on a web application which supports file uploading. I am already familiar checking the size in server side, but i wanted to check the file size in a client side.
I know its a browser limitation that we cant access the file properties for security reasons. So i have tried both swfupload and uploadify component. Both are good and serve the needs.
But the limitation is both depends on flash, so if my end user not installed flash then i would end up in a problem. Asking them to install flash is another thing, but its a web portal and the user base is huge. So i don’t like the idea of asking them to install flash.
Today i came across file upload functionality in gmail. And tested this in browser(IE) without having flash installed. What i found was interesting. If you upload a big file, they made a postback and immediately returning the message the file size is too large.
How this is possible, how they can find the size of the file without downloading the whole content.? I believe this must be done by reading HTTP header info. am i right?
So this is the exact functionality i wanted to implement. If the flash is installed already, i can use uploadify to check the size otherwise may be i ll implement-the-never-heardof-technique-used-by-google.
can someone recommend me how to do this?
anybody faced the similar problems earlier, what have you done??
Update:
Gmail upload with flash installed in FF
without flash in IE
After lot of searching i found we can use maxAllowedContentLength to limit the upload size in ASP.Net applications. Remember this settings work only on IIS 7 or above.
Since this is handled in IIS level, we dont need to handle anything in server code. If the size limit exceeds, it will return the error code 404.13. So you can easily check the code in client side to determine the problem.
This is what i have done to handle the large files if the flash is not installed in the client machine.
Hope this may help someone.
For more info read about this settings, read this