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by Boon-Hau Teh (boonhau.teh at utoronto.ca)
July 25, 2008
ATutor
http://www.atutor.ca/
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Overview
Fluid's Uploader can be integrated into a learning content management system, such as ATutor. Files are uploaded for several purposes such as uploading images for teaching material, student-submitted assignments, and audio tutorial files. The integration of Fluid's Uploader improves the user experience by allowing for multiple file uploads along with the progress bar and pause/resume features. ATutor aims to integrate Fluid's Uploader into its File Manager and have it ready for its next release (ATutor 1.6.2).
Implementation
Fluid's Uploader script is called by the File Manager which is used in several places in ATutor, such as:
(logged in to an instructor account)
- Manage -> File Manager
- Content Editor -> File Manager
- Manage -> Tests -> Edit -> File Manager
Starting from ATutor 1.6.2, the entire source code of the Fluid Package is installed under /jscripts/fluid-components in the ATutor installation directory. In previous releases, only files from /fluid-components/js were installed directly in /jscripts and did not include folders such as /css and /swfupload.
Initialization
When using the Fluid scripts, they need to be loaded and initialized in the header of a page. This is done by saving the necessary tags to the $_custom_head variable (in /tools/filemanager/index.php), which gets passed to /tools/filemanager/top.php to be written from the appropriate header include file. Most of the HTML code being used is borrowed from the sample-code provided by the Fluid Package in /sample-code/uploader/inline/uploader.html with changes made to paths and settings.
$fluid_dir = 'jscripts/fluid-components/';
$current_path = AT_CONTENT_DIR.$_SESSION['course_id'].'/';
$pathext = urldecode($_GET['pathext']);
$_custom_head .= '
<link href="'.$fluid_dir.'css/infusion-theme.css" rel="stylesheet" type="text/css" />
<link href="'.$fluid_dir.'css/Uploader.css" rel="stylesheet" type="text/css" />
<script src="'.$fluid_dir.'js/jquery/jquery-1.2.3.js" type="text/javascript"></script>
<script src="'.$fluid_dir.'js/jquery/jquery.tabindex.js" type="text/javascript"></script>
<script src="'.$fluid_dir.'js/jquery/jARIA.js" type="text/javascript"></script>
<script src="'.$fluid_dir.'js/jquery/jquery.dimensions.js" type="text/javascript"></script>
<script src="'.$fluid_dir.'js/jquery/ui.base.js" type="text/javascript"></script>
<script src="'.$fluid_dir.'js/jquery/jquery.keyboard-a11y.js" type="text/javascript"></script>
<script src="'.$fluid_dir.'js/swfupload/swfupload.js" type="text/javascript"></script>
<script src="'.$fluid_dir.'js/fluid/Fluid.js" type="text/javascript"></script>
<script src="'.$fluid_dir.'js/fluid/Uploader.js" type="text/javascript"></script>
<script language="JavaScript" type="text/javascript">
var uploadURL = "include/lib/upload.php?path='.urlencode($current_path.$pathext).'";
var flashURL = "jscripts/fluid-components/swfupload/swfupload_f9.swf";
var settings = {
whenDone: "'.$_SERVER['PHP_SELF'].'?pathext='.urlencode($pathext)
.SEP.'popup='.$popup.SEP.'framed='.$framed.SEP.'msg=FILEUPLOAD_DONE",
whenCancel: function(){},
continueAfterUpload: true,
debug: false
};
var myUpload;
$(document).ready(function() {
myUpload = new fluid.Uploader("single-inline-fluid-uploader", uploadURL, flashURL, settings);
});
</script>
<style type="text/css">
.fluid-uploader {
margin-top: 2em;
padding: 1em 2em;
display: block;
clear: both;
}
</style>
';
The Uploader calls a Flash script (swfupload_f9.swf) to handle most of the functionality, so the url to the swf file must be specified.
var flashURL = "jscripts/fluid-components/swfupload/swfupload_f9.swf";
The Uploader script needs to call a file handler (/include/lib/upload.php) which handles files as necessary after they have been uploaded. The url of the uploader is relative to swfupload_f9.swf
var uploadURL = "include/lib/upload.php?path='.urlencode($current_path.$pathext).'";
The code for the file handler itself is borrowed from the sample code provided in the Fluid Package (/sample-code/uploader.php) with a few alterations, namely the save path of the uploaded files:
$save_path = urldecode($_GET['path']);
Settings for the Uploader can be configured through the "settings" variable. In the current implementation, the Uploader is configured to automatically reload the page (specified by "whenDone") when all the files are done uploading (specified by "continueAfterUpload"). Functionality for the "Cancel" button (specified by "whenCancel") is disabled so that it can be used by a toggle function in ATutor's File Manager (refer to Display section below).
For a more detailed reference of settings that can be configured for the Uploader, please refer to the Uploader API Wiki.
Display
After initializing the Fluid scripts, the Uploader gets displayed through /include/html/filemanager_display.inc.php. Most of the HTML code being used is borrowed from the sample-code provided by the Fluid Package in /sample-code/uploader/inline/uploader.html
Upon opening the File Manager, the Uploader itself is initially hidden in order to save space and keep the page simple. When needed, the user can click on the "Upload Files" button to display Fluid's Uploader interface.
From the Uploader, the "Cancel" button can be clicked to hide the interface and toggle back to the original view of the File Manager.
This toggle feature is a simple Javascript function defined in /include/html/filemanager.inc.php that gets called through the "onclick" attribute of the "Uploade Files" and "Cancel" button.
function toggleform(id, link) {
var obj = document.getElementById(id);
var btn = document.getElementById(link);
if (obj.style.display == "none") {
//show object
obj.style.display='';
obj.focus();
//hide button
btn.style.display = 'none';
} else {
//hide object
obj.style.display='none';
//show button
btn.style.display = '';
}
}
For information on the Uploader interface itself, please refer to the Uploader Wireframes Wiki.
Flash Detection
The current Uploader of the Fluid Package (v0.4beta1) relies on the use of Flash, where swfupload_f9.swf. This poses a problem for an ATutor user who may not have Flash installed. Therefore, it is necessary to provide an alternative method for uploading files when Flash cannot be detected from the user's browser. The current implementation in ATutor does so by providing a simple single-file uploader.
Note that the Flash detection handler will most likely be improved at a later time. For now, the Flash detection takes place outside of the Fluid scripts in /include/vitals.inc.php . If a later version of the Fluid Package implements its own Flash detector and non-Flash script, the current implementation can be easily removed.
if(isset($_COOKIE["flash"])) {
$_SESSION['flash'] = $_COOKIE["flash"];
//delete the cookie
setcookie("flash",'',time()-3600);
}
if (!isset($_SESSION["flash"])) {
$_custom_head .= '
<script type="text/javascript">
<!--
//VB-Script for InternetExplorer
function iExploreCheck()
{
document.writeln("<scr" + "ipt language=\'VBscript\'>");
//document.writeln("\'Test to see if VBScripting works");
document.writeln("detectableWithVB = False");
document.writeln("If ScriptEngineMajorVersion >= 2 then");
document.writeln(" detectableWithVB = True");
document.writeln("End If");
//document.writeln("\'This will check for the plugin");
document.writeln("Function detectActiveXControl(activeXControlName)");
document.writeln(" on error resume next");
document.writeln(" detectActiveXControl = False");
document.writeln(" If detectableWithVB Then");
document.writeln(" detectActiveXControl = IsObject(CreateObject(activeXControlName))");
document.writeln(" End If");
document.writeln("End Function");
document.writeln("</scr" + "ipt>");
return detectActiveXControl("ShockwaveFlash.ShockwaveFlash.1");
}
var plugin = (navigator.mimeTypes && navigator.mimeTypes["application/x-shockwave-flash"]) ?
navigator.mimeTypes["application/x-shockwave-flash"].enabledPlugin : false;
if(!(plugin) && (navigator.userAgent && navigator.userAgent.indexOf("MSIE")>=0
&& (navigator.appVersion.indexOf("Win") != -1))) {
if (iExploreCheck()) {
flash_detect = "flash=yes";
} else {
flash_detect = "flash=no";
}
} else if(plugin) {
flash_detect = "flash=yes";
} else {
flash_detect = "flash=no";
}
writeCookie(flash_detect);
function writeCookie(value)
{
var today = new Date();
var the_date = new Date("December 31, 2099");
var the_cookie_date = the_date.toGMTString();
var the_cookie = value + ";expires=" + the_cookie_date;
document.cookie = the_cookie;
}
//-->
</script>
';
}
In the current implementation, a Flash detection script gets inserted into the header when a user initially accesses any page on ATutor. The script returns a value of "yes" or "no", which gets saved in a cookie ($_COOKIE["flash"]) then sent to the server to be saved as a session variable ($_SESSION['flash']). Once the session variable is set, the cookie is removed and the Flash detection script no longer gets called for the remainder of the session. When accessing the filemanager, the php script (/include/html/filemanager_display.inc.php) generates the appropriate uploader depending on the value of the variable.
if (isset($_SESSION['flash']) && $_SESSION['flash'] == "yes") {
/*
Display Fluid Uploader
*/
} else {
/*
Display non-Flash single file uploader
*/
}
Demo
A working demo of the current Fluid Uploader integrated into ATutor is available at:
http://www.atutor.ca/atutor/fluidtest/
login: fluid
password: fluid
Screenshots
