Standard Adapters

zend-progressbar comes with the following three adapters:

Console Adapter

Zend\ProgressBar\Adapter\Console is a text-based adapter for terminals. It can automatically detect terminal widths, but supports custom widths as well. You can define which elements are displayed with the progressbar as well customize the order of them. You can also define the style of the progressbar itself.

Automatic console width recognition

shell_exec() is required for this feature to work on *nix based systems. On Windows, there is always a fixed terminal width of 80 characters, so no recognition is required there.

You can set the adapter options either via the set*() methods, or provide an array or Traversable instance with options as first parameter to the constructor. The available options are:

Option name Type Description
outputStream string|resource A different output stream, if you don't want to stream to STDOUT. Can be any other stream like php://stderr or a path to a file.
width int|ProgressBar::AUTO Console width to use; ProgressBar::AUTO indicates the adapter should autodetect the width.
elements null|array Which elements to include in the display; null to include all, or an array with one of the Console constants, as detailed below.
textWidth int Width in characters of the ELEMENT_TEXT element. Default is 20.
charset string Charset of the ELEMENT_TEXT element. Default is utf-8.
barLeftChar string String to use on the left-hand side of the progressbar indicator.
barRightChar string String to use on the right-hand side of the progressbar indicator.
barIndicatorChar string String to use within the progressbar indicator to indicate progress; can be empty.

To determine which elements to display in the progressbar, use one or more of the following constants:

Option name Description
ELEMENT_PERCENT The current value in percent.
ELEMENT_BAR The visual bar which display the percentage.
ELEMENT_ETA The automatic calculated ETA. This element is firstly displayed after five seconds, because in this time, it is not able to calculate accurate results.
ELEMENT_TEXT An optional status message about the current process.

JsPush Adapter

Zend\ProgressBar\Adapter\JsPush is an adapter allowing you to update a browser-based progressbar via Javascript Push. This means that no second connection is required to gather the status about a running process, but that the process itself sends its status directly to the browser.

You can set the adapter options either via the set() methods or provide an array or Traversable instance with options as the first parameter to the constructor. The available options are:

Option name Type Description
updateMethodName string The JavaScript method which should be called on every update. Default value is Zend\ProgressBar\Update.
finishMethodName null|string The JavaScript method which should be called when sending the finish status. Default value is NULL, which means nothing is done.

To use this adapter, first create a progressbar in your browser, either with JavaScript or plain HTML. Then define the update method and optionally a finish method in JavaScript; both should expect a JSON object as the only argument. Then call a webpage with the long-running process in a hidden iframe or object tag. While the process is running, the adapter will call the update method on every update with a JSON object, containing the following parameters:

Parameter Description
current The current absolute value detailing upload status.
max The max absolute value, indicating total upload size.
percent The calculated percentage complete of the upload.
timeTaken The elapsed time of the upload currently.
timeRemaining The expected time until the upload finishes.
text The optional status message, if given.

Basic example for the client-side

This example illustrates a basic setup of HTML, CSS, and JavaScript for the JsPush adapter

<div id="zend-progressbar-container">
    <div id="zend-progressbar-done"></div>
</div>

<iframe src="long-running-process.php" id="long-running-process"></iframe>
#long-running-process {
    position: absolute;
    left: -100px;
    top: -100px;

    width: 1px;
    height: 1px;
}

#zend-progressbar-container {
    width: 100px;
    height: 30px;

    border: 1px solid #000000;
    background-color: #ffffff;
}

#zend-progressbar-done {
    width: 0;
    height: 30px;

    background-color: #000000;
}
function Zend\ProgressBar\Update(data)
{
    document.getElementById('zend-progressbar-done').style.width = data.percent + '%';
}

This will create a container with a black border and a block which indicates the current process. You should not hide the iframe or object using display: none;, as some browsers (such as Safari 2) will not load the actual content then.

Instead of creating your custom progressbar, you may want to use one of the available JavaScript libraries like Dojo, jQuery etc.:

Interval of updates

Do not send too many updates, as every update has a minimum size of 1kb. This is a requirement for the Safari browser to actually render and execute the function call. Internet Explorer has a similar limitation of 256 bytes.

JsPull Adapter

Zend\ProgressBar\Adapter\JsPull is the opposite of JsPush, as it requires the browser to pull for new updates, instead of pushing updates directly without intervention.

In general, you should use this adapter with the persistence option of the Zend\ProgressBar\ProgressBar. On notify, the adapter sends a JSON string to the browser, which looks exactly like the JSON string which is sent by the JsPush adapter, with one difference: it contains an additional parameter, finished, which is either false when update() is called or true, when finish() is called.

You can set the adapter options either via the set*() methods, or give an array or Traversable instance with options as first parameter to the constructor. The available options are:

Option name Type Description
exitAfterSend bool Whether or not to exit the current request after the data is sent to the browser; default is true.