preview.php

<?php
// This file is part of Moodle - http://moodle.org/
//
// This program 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.
//
// This program 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/>.

/**
 * Fetches object preview from repository
 *
 * @package    atto_edusharing
 * @copyright  metaVentis GmbH — http://metaventis.com
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

// Create preview link with signature.
require_once(__DIR__ . '/../../../../../config.php');
require_once($CFG->dirroot . '/lib/setup.php');
require_once($CFG->libdir.'/filelib.php');
require_once($CFG->dirroot . '/mod/edusharing/lib.php');

require_login();

global $DB, $USER;

$resourceid = optional_param('resourceId', 0, PARAM_INT);

if (!$edusharing = $DB->get_record('edusharing', array('id' => $resourceid))) {
    trigger_error(get_string('error_loading_instance', 'editor_edusharing'), E_USER_WARNING);
}

$previewservice = get_config('edusharing', 'application_cc_gui_url') . '/' . 'preview';

$time = round(microtime(true) * 1000);

$url = $previewservice;
$url .= '?appId=' . get_config('edusharing', 'application_appid');
$url .= '&courseId=' . $edusharing->course;
$url .= '&repoId=' . edusharing_get_repository_id_from_url($edusharing->object_url);
$url .= '&proxyRepId=' . get_config('edusharing', 'application_homerepid');
$url .= '&nodeId=' . edusharing_get_object_id_from_url($edusharing->object_url);
$url .= '&resourceId=' . $resourceid;
$url .= '&version=' . $edusharing->object_version;
$sigdata = get_config('edusharing', 'application_appid') . $time . edusharing_get_object_id_from_url($edusharing->object_url);
$sig = urlencode(edusharing_get_signature($sigdata));
$url .= '&sig=' . $sig;
$url .= '&signed=' . $sigdata;
$url .= '&ts=' . $time;

$curl = new curl();
$curl->setopt( array(
    'CURLOPT_SSL_VERIFYPEER' => false,
    'CURLOPT_SSL_VERIFYHOST' => false,
    'CURLOPT_FOLLOWLOCATION' => 1,
    'CURLOPT_HEADER' => 0,
    'CURLOPT_RETURNTRANSFER' => 1,
    'CURLOPT_USERAGENT' => $_SERVER['HTTP_USER_AGENT'],
    ));

$output = $curl->get($url);

if ($curl->error) {
    debugging('cURL Error: '.$curl->error);
    echo 'cURL Error: '.$curl->error;
    exit();
}

$curlinfo = $curl->get_info();
header('Content-type: ' . $curlinfo['content_type']);
echo $output;
exit();