Displaying an upload progress bar

Especially when importing a large file, it's interesting to have a visual feedback on the progression of upload. Please note that the progress bar we are discussing here informs us only about the uploading part, which is a subset of the whole import operation.

Having a JavaScript-enabled browser is a requirement for this feature. Moreover, the web server's PHP component must have the JSON extension and at least one of these extensions:

• The well-know APC extension (http://pecl.php.net/package/APC), which is highly recommended anyway for its opcode caching benefits

• The uploadprogress extension (http://pecl.php.net/package/uploadprogress)

phpMyAdmin uses AJAX techniques to fetch progress information, then displays it as part of the File to import dialog. The number of bytes uploaded, total number of bytes, and percentage uploaded are displayed under the bar.

Configuring APC

A few php.ini directives play an important role for upload progress. First, the apc.rfc1867...