File Upload Handlers

zend-progressbar provides handlers that can give you the actual state of a file upload in progress. To use this feature you need to choose one of the upload progress handlers (APC, uploadprogress, or session) and ensure that your server setup has the appropriate extension or feature enabled. All of the progress handlers use the same interface.

When uploading a file via HTTP POST, you must also include the progress identifier in a hidden input. The File Upload Progress View Helpers provide a convenient way to add the hidden input based on your handler type.

Methods of Reporting Progress

There are two methods for reporting the current upload progress status: using a ProgressBar Adapter, or using the returned status array manually.

Using a ProgressBar Adapter

A zend-progressbar adapter can be used to display upload progress to your users.

use Zend\I18n\Filter\Alnum as AlnumFilter;
use Zend\ProgressBar\Adapter;
use Zend\ProgressBar\Upload;

$adapter  = new Adapter\JsPush();
$progress = new Upload\SessionProgress();

$filter   = new AlnumFilter(false, 'en_US');
$id       = $filter->filter($_GET['id']);

$status   = null;
while (empty($status['done'])) {
    $status = $progress->getProgress($id);
}

Each time the getProgress() method is called, the adapter will be updated.

Using the Status Array

You can also work manually with getProgress() without using an adapter.

getProgress() will return an array with several keys. They will sometimes differ based on the specific upload handler used, but the following keys are always standard:

Key name Description
total The total file size of the uploaded file(s) in bytes as integer.
current The current uploaded file size in bytes as integer.
rate The average upload speed in bytes per second as integer.
done Returns TRUE when the upload is finished and FALSE otherwise.
message A status message. Either the progress as text in the form 10kB / 200kB, or a helpful error message in the case of a problem (such as: no upload in progress, failure while retrieving the data for the progress, or that the upload has been canceled).

All other returned keys are provided directly from the specific handler.

An example of using the status array manually:

use Zend\ProgressBar\Upload\SessionProgress;
use Zend\View\Model\JsonModel;

// In a Controller...

public function sessionProgressAction()
{
    $id = $this->params()->fromQuery('id', null);
    $progress = new SessionProgress();
    return new JsonModel($progress->getProgress($id));
}

// Returns JSON
//{
//    "total"    : 204800,
//    "current"  : 10240,
//    "rate"     : 1024,
//    "message"  : "10kB / 200kB",
//    "done"     : false
//}

Standard Handlers

zend-progressbar comes with the following three upload handlers:

APC Progress Handler

Zend\ProgressBar\Upload\ApcProgress uses the APC extension for tracking upload progress.

Extension required

The APC extension is required when using this handler.

This handler is best used with the FormFileApcProgress view helper, to provide a hidden element with the upload progress identifier.

Session Progress Handler

The Zend\ProgressBar\Upload\SessionProgress handler uses the PHP Session Progress feature for tracking upload progress.

This handler is best used with the FormFileSessionProgress view helper, to provide a hidden element with the upload progress identifier.

Upload Progress Handler

The Zend\ProgressBar\Upload\UploadProgress handler uses the PECL Uploadprogress extension for tracking upload progress.

Extension required

The PECL Uploadprogress extension is required in order to use this handler.

This handler is best used with the FormFileUploadProgress view helper, to provide a hidden element with the upload progress identifier.