=head1 NAME JavaScript_Guide for Apache::UploadMeter =head1 SYNOPSIS // Register a global callback UploadMeter.Responders.register({ onCreate: function (meter) { Element.update(meter.desc, "Please wait..."); } }); // Create a new UploadMeter var um = new UploadMeter(el, meter_id, meter_url, { // Callback to be executed every time we get a status update onUpdate: function (status, last) { Element.update('file', "Now uploading: " + status.filename); Element.update('bytes', status.seen + "/" + status.total + " bytes transfered (" + Util.formatDec(status.currentrate) + " bytes/sec)"); Element.update('time', Util.formatTime(status.elapsed) + " elapsed (" + Util.formatTime(status.remaining) + " remaining)"); }, onFinished: function(status, last) { // Callback to be executed when we've detected a complete upload and stop the meter Element.show('closeme'); } }); // Start our uploadmeter - only do this once the corresponding upload has started (or is about to start) um.start(); // Stop (or pause) a previouslky start()ed meter um.stop(); // Un-register the default pop-up window behavior Event.stopObserving(aum_el, 'submit', aum_popup); =head1 DESCRIPTION Apache::UploadMeter includes several JavaScript objects to help quickly create a customized GUI interface for Apache::UploadMeter using the JSON meter type =head1 DOM, JavaScript and Cascading StyleSheet rules Although we aim to give maximum customizability, in order to keep a balance between ease of initial set-up and basic usage, and customizability, the built-in UploadMeter includes JS code and CSS rules for a simple graphical progress-bar. At the current moment, the constructor for the UploadMeter object requires a reference to a DOM node as one of the parameters, to be used as the base for creating this progress bar. If you don't want to use the built-in progress-bar, but also don't want to muck with the UploadMeter object to get around this, just create an empty DIV on your page, set the style to hidden (eg, display: none), and pass that to the UploadMeter object. If you do wish to use this built-in object, ensure that the CSS class of this div is "uploadmeter" (and don't hide it!) Also, it is worth noting that the default behavior looks for an element class named "uploadform" and attempts to add to the onSubmit code for it, to trigger the bundled default pop-up window. If you don't want this to happen, just run: C =head1 API Documentation =head3 UploadMeter Object This is where most of the action happens. The public interface to this object consists of a constructor, start and stop methods, and some callbacks that can be used to do extra stuff at various key points in the UploadMeter's lifetime. =over =item * UploadMeter(I, I, I, I) This is the default constructor for a new UploadMeter instance. It accepts 3 mandatory parameters and a hash of additional options. The first parameter, I is a DIV element under which to create a graphical progress-bar (see L above). The second parameter is the unique identifier of the uploadmeter data you wish to use. If you're using MeterType JSON, this will be embedded in your JavaScript as I. The third parameter is the URL of the meter-status URL. If you're using MeterType JSON, this will be embedded in your JavaScript as I. The final parameter is a hash of additional optional configuration directives and callback routines. =over =item * Parameters =over =item * delay The delay (in seconds or partial seconds) between meter updates. The default value (3) should probably be good enough for you. As a warning, if you set this too high, your users will not have a good feel for what's happening. Too low and (besided the extra traffic to your server), the animation for the progress-bar may garble (this is known to happen if 2 animation requests happen simultaniously. While this will likely eventually be fixed, as of the time of writing, it's not. =back =item * Callback routines The callback routines all contain zero, one or two parameters. The parameter order will always be I, I. I contains the current status of the upload. I always contains the B status of the uploadmeter, such that on a repeating callback such as onUpdate, the value of any given request's I will always be the same as the previous callback's I. The parameters contain the following information: =over =item * meter_id Contains the meter_id for the current upload =item * filename Contains the filename (as supplied by the client) of the currently uploading file =item * finished Contains a boolean value which will be set to 1 once the upload is complete =item * status =over =item * timestamp Current timestamp from server, as seconds since the epoch =item * start Timestamp (as seconds since the epoch) when upload was started =item * received Number of bytes received so far =item * total Total number of bytes in the upload (more accurately, of the upload B including other form information) =back =item * total This is a shortcut for C =item * seen This is a shortcut for C =item * progress A value between 0 and 100, representing the percentage of the upload that has been completed. =item * currentrate The approximate current upload rate (in bytes/second) =item * elapsed The time (in seconds) which has elapsed since the upload started =item * remaining The approximate time (in seconds) remaining in the upload =back The callbacks currently available are: =over =item * onCreate(I<>) This callback is called once just before the first AJAX call is made. As such, it doesn't happen on construction; it happens after um.start(), but before the initial AJAX request is made. I know it's not really well named, but you're welcom to suggest something better. =item * onInitialize(I, I) This callback is called once after the initial AJAX response is received and parsed. While I is generally useless at this point (it's a subset of I right now), it's provided in case you want to change the value of anything in it. =item * onUpdate(I, I) This callback is called every time data is updated from meter URL. It can be utilized to update other GUI elements, such as is done in the default pop-up. =item * onFinished(I, I) This callback is called after onUpdate if the upload is determined to be complete (eg, C) =back =back =back =head3 UploadMeter.Responders In addition to adding handlers to individual UploadMeter objects, as described above, you can also add global callbacks which will be called for *every* uploadmeter on the page. This might be useful, for example, for Web 2.0 applications that allow for multiple asynchronous uploads in separate requests. In such a case, rather than registering identical handlers for each UploadMeter instance, you can register a single function globally and it will be called for the appropriate callback for all UploadMeter instances running on the page. Callbacks that are registered this way will receive, as the first parameter, the UploadMeter object of the instance which is currently calling into it. =head3 Util The Util namespace is not an object, but rather a namespace to group some helper utility functions that may make your life a bit easier when creating your custom user interface. =over =item * Util.formatTime(I) This function takes a single parameter, I which is a numeric value corresponding to a number of seconds. This is not necessarily a "unix timestamp" (the number of seconds since the epoch) but rather an arbitrary number of seconds. The function will return a formatted string returning the number of seconds in HH:mm:ss format =item * Util.formatDec(I) This function takes a numeric (decimal/floating point) value as a parameter and returns a string containing the number and 2 decimal points. =back =head1 AUTHOR AND COPYRIGHT Copyright (c) 2001-2007 Issac Goldstand Emargol@beamartyr.netE - All rights reserved. This library is free software. It can be redistributed and/or modified under the same terms as Perl itself. This software contains third-party components licensed under BSD and MIT style open-source licenses. =head1 SEE ALSO L =cut