Basicaly because of crossbrowser compatibility. In fact it is supported by any* browser.
How to use?
$p = new FileUploadProgress("unique_file_description");
// ... insert in upload form before file field
// and now get upload progress info
$arrayWithThings = $p->getProgress(); // this will throw an exception if no/wrong data
File upload track should be done using ajax or frames, php script with file data(from $_FILES) will be available
after upload only, and this class make no sense if used in that script.
What to install before to get it working?
- To enable upload track support install and configure apc:
apc.rfc1867 = 1
- Or to install uploadprogress PHP extension
- Or to install PHP 5.4< and set: session.upload_progress.enabled = 1 ;set by default here