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<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* This plugin is used to access equella repositories.
*
* @since Moodle 2.3
* @package repository_equella
* @copyright 2012 Dongsheng Cai {@link http://dongsheng.org}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
require_once($CFG->dirroot . '/repository/lib.php');
/**
* repository_equella class implements equella_client
*
* @since Moodle 2.3
* @package repository_equella
* @copyright 2012 Dongsheng Cai {@link http://dongsheng.org}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class repository_equella extends repository {
/** @var array mimetype filter */
private $mimetypes = array();
/**
* Constructor
*
* @param int $repositoryid repository instance id
* @param int|stdClass $context a context id or context object
* @param array $options repository options
*/
public function __construct($repositoryid, $context = SYSCONTEXTID, $options = array()) {
parent::__construct($repositoryid, $context, $options);
if (isset($this->options['mimetypes'])) {
$mt = $this->options['mimetypes'];
if (!empty($mt) && is_array($mt) && !in_array('*', $mt)) {
$this->mimetypes = array_unique(array_map(array($this, 'to_mime_type'), $mt));
}
}
}
/**
* Display embedded equella interface
*
* @param string $path
* @param mixed $page
* @return array
*/
public function get_listing($path = null, $page = null) {
global $COURSE;
$callbackurl = new moodle_url('/repository/equella/callback.php', array('repo_id'=>$this->id));
$mimetypesstr = '';
$restrict = '';
if (!empty($this->mimetypes)) {
$mimetypesstr = '&mimeTypes=' . implode(',', $this->mimetypes);
// We're restricting to a mime type, so we always restrict to selecting resources only.
$restrict = '&attachmentonly=true';
} else if ($this->get_option('equella_select_restriction') != 'none') {
// The option value matches the EQUELLA paramter name.
$restrict = '&' . $this->get_option('equella_select_restriction') . '=true';
}
$url = $this->get_option('equella_url')
. '?method=lms'
. '&returnurl='.urlencode($callbackurl)
. '&returnprefix=tle'
. '&template=standard'
. '&token='.urlencode($this->getssotoken('write'))
. '&courseId='.urlencode($COURSE->idnumber)
. '&courseCode='.urlencode($COURSE->shortname)
. '&action=searchThin'
. '&forcePost=true'
. '&cancelDisabled=true'
. '&attachmentUuidUrls=true'
. '&options='.urlencode($this->get_option('equella_options') . $mimetypesstr)
. $restrict;
$manageurl = $this->get_option('equella_url');
$manageurl = str_ireplace('signon.do', 'logon.do', $manageurl);
$manageurl = $this->appendtoken($manageurl);
$list = array();
$list['object'] = array();
$list['object']['type'] = 'text/html';
$list['object']['src'] = $url;
$list['nologin'] = true;
$list['nosearch'] = true;
$list['norefresh'] = true;
$list['manage'] = $manageurl;
return $list;
}
/**
* Supported equella file types
*
* @return int
*/
public function supported_returntypes() {
return (FILE_INTERNAL | FILE_REFERENCE);
}
/**
* Prepare file reference information
*
* @param string $source
* @return string file referece
*/
public function get_file_reference($source) {
// Internally we store serialized value but user input is json-encoded for security reasons.
$ref = json_decode(base64_decode($source));
$filename = clean_param($ref->filename, PARAM_FILE);
$url = clean_param($ref->url, PARAM_URL);
return base64_encode(serialize((object)array('url' => $url, 'filename' => $filename)));
}
/**
* Counts the number of failed connections.
*
* If we received the connection timeout more than 3 times in a row, we don't attemt to
* connect to the server any more during this request.
*
* This function is used by {@link repository_equella::sync_reference()} that
* synchronises the file size of referenced files.
*
* @param int $errno omit if we just want to know the return value, the last curl_errno otherwise
* @return bool true if we had less than 3 failed connections, false if no more connections
* attempts recommended
*/
private function connection_result($errno = null) {
static $countfailures = array();
$sess = sesskey();
if (!array_key_exists($sess, $countfailures)) {
$countfailures[$sess] = 0;
}
if ($errno !== null) {
if ($errno == 0) {
// reset count of failed connections
$countfailures[$sess] = 0;
} else if ($errno == 7 /*CURLE_COULDNT_CONNECT*/ || $errno == 9 /*CURLE_REMOTE_ACCESS_DENIED*/) {
// problems with server
$countfailures[$sess]++;
}
}
return ($countfailures[$sess] < 3);
}
/**
* Download a file, this function can be overridden by subclass. {@link curl}
*
* @param string $reference the source of the file
* @param string $filename filename (without path) to save the downloaded file in the
* temporary directory
* @return null|array null if download failed or array with elements:
* path: internal location of the file
* url: URL to the source (from parameters)
*/
public function get_file($reference, $filename = '') {
global $USER, $CFG;
$ref = @unserialize(base64_decode($reference));
if (!isset($ref->url) || !($url = $this->appendtoken($ref->url))) {
// Occurs when the user isn't known..
return null;
}
$path = $this->prepare_file($filename);
$cookiepathname = $this->prepare_file($USER->id. '_'. uniqid('', true). '.cookie');
$c = new curl(array('cookie'=>$cookiepathname));
$result = $c->download_one($url, null, array('filepath' => $path, 'followlocation' => true, 'timeout' => $CFG->repositorygetfiletimeout));
// Delete cookie jar.
if (file_exists($cookiepathname)) {
unlink($cookiepathname);
}
if ($result !== true) {
throw new moodle_exception('errorwhiledownload', 'repository', '', $result);
}
return array('path'=>$path, 'url'=>$url);
}
public function sync_reference(stored_file $file) {
global $USER, $CFG;
if ($file->get_referencelastsync() + DAYSECS > time() || !$this->connection_result()) {
// Synchronise not more often than once a day.
// if we had several unsuccessfull attempts to connect to server - do not try any more.
return false;
}
$ref = @unserialize(base64_decode($file->get_reference()));
if (!isset($ref->url) || !($url = $this->appendtoken($ref->url))) {
// Occurs when the user isn't known..
$file->set_missingsource();
return true;
}
$cookiepathname = $this->prepare_file($USER->id. '_'. uniqid('', true). '.cookie');
$c = new curl(array('cookie' => $cookiepathname));
if (file_extension_in_typegroup($ref->filename, 'web_image')) {
$path = $this->prepare_file('');
$result = $c->download_one($url, null, array('filepath' => $path, 'followlocation' => true, 'timeout' => $CFG->repositorysyncimagetimeout));
if ($result === true) {
$file->set_synchronised_content_from_file($path);
return true;
}
} else {
$result = $c->head($url, array('followlocation' => true, 'timeout' => $CFG->repositorysyncfiletimeout));
}
// Delete cookie jar.
if (file_exists($cookiepathname)) {
unlink($cookiepathname);
}
$this->connection_result($c->get_errno());
$curlinfo = $c->get_info();
if (isset($curlinfo['http_code']) && $curlinfo['http_code'] == 200
&& array_key_exists('download_content_length', $curlinfo)
&& $curlinfo['download_content_length'] >= 0) {
// we received a correct header and at least can tell the file size
$file->set_synchronized(null, $curlinfo['download_content_length']);
return true;
}
$file->set_missingsource();
return true;
}
/**
* Repository method to serve the referenced file
*
* @param stored_file $storedfile the file that contains the reference
* @param int $lifetime Number of seconds before the file should expire from caches (null means $CFG->filelifetime)
* @param int $filter 0 (default)=no filtering, 1=all files, 2=html files only
* @param bool $forcedownload If true (default false), forces download of file rather than view in browser/plugin
* @param array $options additional options affecting the file serving
*/
public function send_file($stored_file, $lifetime=null , $filter=0, $forcedownload=false, array $options = null) {
$reference = unserialize(base64_decode($stored_file->get_reference()));
$url = $this->appendtoken($reference->url);
if ($url) {
header('Location: ' . $url);
} else {
send_file_not_found();
}
}
/**
* Add Instance settings input to Moodle form
*
* @param moodleform $mform
*/
public static function instance_config_form($mform) {
$mform->addElement('text', 'equella_url', get_string('equellaurl', 'repository_equella'));
$mform->setType('equella_url', PARAM_URL);
$strrequired = get_string('required');
$mform->addRule('equella_url', $strrequired, 'required', null, 'client');
$mform->addElement('text', 'equella_options', get_string('equellaoptions', 'repository_equella'));
$mform->setType('equella_options', PARAM_NOTAGS);
$choices = array(
'none' => get_string('restrictionnone', 'repository_equella'),
'itemonly' => get_string('restrictionitemsonly', 'repository_equella'),
'attachmentonly' => get_string('restrictionattachmentsonly', 'repository_equella'),
);
$mform->addElement('select', 'equella_select_restriction', get_string('selectrestriction', 'repository_equella'), $choices);
$mform->addElement('header', 'groupheader',
get_string('group', 'repository_equella', get_string('groupdefault', 'repository_equella')));
$mform->addElement('text', 'equella_shareid', get_string('sharedid', 'repository_equella'));
$mform->setType('equella_shareid', PARAM_RAW);
$mform->addRule('equella_shareid', $strrequired, 'required', null, 'client');
$mform->addElement('text', 'equella_sharedsecret', get_string('sharedsecrets', 'repository_equella'));
$mform->setType('equella_sharedsecret', PARAM_RAW);
$mform->addRule('equella_sharedsecret', $strrequired, 'required', null, 'client');
foreach (self::get_all_editing_roles() as $role) {
$mform->addElement('header', 'groupheader_'.$role->shortname, get_string('group', 'repository_equella',
role_get_name($role)));
$mform->addElement('text', "equella_{$role->shortname}_shareid", get_string('sharedid', 'repository_equella'));
$mform->setType("equella_{$role->shortname}_shareid", PARAM_RAW);
$mform->addElement('text', "equella_{$role->shortname}_sharedsecret",
get_string('sharedsecrets', 'repository_equella'));
$mform->setType("equella_{$role->shortname}_sharedsecret", PARAM_RAW);
}
}
/**
* Names of the instance settings
*
* @return array
*/
public static function get_instance_option_names() {
$rv = array('equella_url', 'equella_select_restriction', 'equella_options',
'equella_shareid', 'equella_sharedsecret'
);
foreach (self::get_all_editing_roles() as $role) {
array_push($rv, "equella_{$role->shortname}_shareid");
array_push($rv, "equella_{$role->shortname}_sharedsecret");
}
return $rv;
}
/**
* Generate equella token
*
* @param string $username
* @param string $shareid
* @param string $sharedsecret
* @return string
*/
private static function getssotoken_raw($username, $shareid, $sharedsecret) {
$time = time() . '000';
return urlencode($username)
. ':'
. $shareid
. ':'
. $time
. ':'
. base64_encode(pack('H*', md5($username . $shareid . $time . $sharedsecret)));
}
/**
* Append token
*
* @param string $url
* @param $readwrite
* @return string
*/
private function appendtoken($url, $readwrite = null) {
$ssotoken = $this->getssotoken($readwrite);
if (!$ssotoken) {
return false;
}
return $url . (strpos($url, '?') != false ? '&' : '?') . 'token=' . urlencode($ssotoken);
}
/**
* Generate equella sso token
*
* @param string $readwrite
* @return string
*/
private function getssotoken($readwrite = 'read') {
global $USER;
if (empty($USER->username)) {
return false;
}
if ($readwrite == 'write') {
foreach (self::get_all_editing_roles() as $role) {
if (user_has_role_assignment($USER->id, $role->id, $this->context->id)) {
// See if the user has a role that is linked to an equella role.
$shareid = $this->get_option("equella_{$role->shortname}_shareid");
if (!empty($shareid)) {
return $this->getssotoken_raw($USER->username, $shareid,
$this->get_option("equella_{$role->shortname}_sharedsecret"));
}
}
}
}
// If we are only reading, use the unadorned shareid and secret.
$shareid = $this->get_option('equella_shareid');
if (!empty($shareid)) {
return $this->getssotoken_raw($USER->username, $shareid, $this->get_option('equella_sharedsecret'));
}
}
private static function get_all_editing_roles() {
return get_roles_with_capability('moodle/course:manageactivities', CAP_ALLOW);
}
/**
* Convert moodle mimetypes list to equella format
*
* @param string $value
* @return string
*/
private static function to_mime_type($value) {
return mimeinfo('type', $value);
}
/**
* Return the source information
*
* @param string $source
* @return string|null
*/
public function get_file_source_info($source) {
$ref = json_decode(base64_decode($source));
$filename = clean_param($ref->filename, PARAM_FILE);
return 'EQUELLA: ' . $filename;
}
/**
* Return human readable reference information
* {@link stored_file::get_reference()}
*
* @param string $reference
* @param int $filestatus status of the file, 0 - ok, 666 - source missing
* @return string
*/
public function get_reference_details($reference, $filestatus = 0) {
if (!$filestatus) {
$ref = unserialize(base64_decode($reference));
return $this->get_name(). ': '. $ref->filename;
} else {
return get_string('lostsource', 'repository', '');
}
}
/**
* Is this repository accessing private data?
*
* @return bool
*/
public function contains_private_data() {
return false;
}
}