File Upload Handlers
Zend\ProgressBar\Upload 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 with a form POST, you must also include the progress identifier in a hidden input. The :ref:`File Upload Progress View Helpers <zend.form.view.helper.file>` 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. By either using a ProgressBar Adapter, or by using the returned status array manually.
Using a ProgressBar Adapter
A Zend\ProgressBar adapter can be used to display upload progress to your users.
Each time the getProgress() method is called, the ProgressBar adapter will be updated.
Using the Status Array
You can also work manually with getProgress() without using a Zend\ProgressBar adapter.
The getProgress() will return you an array with several keys. They will sometimes differ based on the specific Upload handler used, but the following keys are always standard:
- 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. Problems 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:
Zend\ProgressBar\Upload comes with the following three upload handlers: