Zend Framework 1.7.9 Manual
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Zend_ProgressBar is a component to create and update
progressbars in different environments. It consists of a single
backend, which outputs the progress through one of the multiple
adapters. On every update, it takes an absolute value and optionally
a status message, and then calls the adapter with some precalculated
values like percentage and estimated time left.
Zend_ProgressBar is quite easy in it's usage. You
simply create a new instance of Zend_Progressbar, defining a
min- and a max-value, and choose an adapter to output the data. If
you want to process a file, you would do something like:
$progressBar = new Zend_ProgressBar($adapter, 0, $fileSize);
while (!feof($fp)) {
// Do something
$progressBar->update($currentByteCount);
}
$progressBar->finish();
In the first step, an instance of Zend_ProgressBar is
created, with a specific adapter, a min-value of 0 and a max-value
of the total filesize. Then a file is processed and in every loop
the progressbar is updated with the current byte count. At the end
of the loop, the progressbar status is set to finished.
You can also call the update() method of
Zend_ProgressBar without arguments, which just
recalculates ETA and notifies the adapter. This is useful when there
is no data update but you want the progressbar to be updated.
If you want the progressbar to be persistent over multiple requests,
you can give the name of a session namespace as fourth argument
to the constructor. In that case, the progressbar will not notify
the adapter within the constructor, but only when you call
update() or finish(). Also the current
value, the status text and the start time for ETA calculation will
be fetched in the next request run again.
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