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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/>.
/**
* Defines backup_xml_transformer class
*
* @package core_backup
* @subpackage moodle2
* @category backup
* @copyright 2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
// Cache for storing link encoders, so that we don't need to call
// register_link_encoders each time backup_xml_transformer is constructed
// TODO MDL-25290 replace global with MUC code.
global $LINKS_ENCODERS_CACHE;
$LINKS_ENCODERS_CACHE = array();
/**
* Class implementing the @xml_contenttransformed logic to be applied in moodle2 backups
*
* TODO: Finish phpdocs
*/
class backup_xml_transformer extends xml_contenttransformer {
private $absolute_links_encoders; // array of static methods to be called in order to
// perform the encoding of absolute links to all the
// contents sent to xml
private $courseid; // courseid this content belongs to
private $unicoderegexp; // to know if the site supports unicode regexp
public function __construct($courseid) {
$this->absolute_links_encoders = array();
$this->courseid = $courseid;
// Check if we support unicode modifiers in regular expressions
$this->unicoderegexp = @preg_match('/\pL/u', 'a'); // This will fail silently, returning false,
// if regexp libraries don't support unicode
// Register all the available content link encoders
$this->absolute_links_encoders = $this->register_link_encoders();
}
public function process($content) {
// Array or object, debug and try our best recursively, shouldn't happen but...
if (is_array($content)) {
debugging('Backup XML transformer should not process arrays but plain content only', DEBUG_DEVELOPER);
foreach($content as $key => $plaincontent) {
$content[$key] = $this->process($plaincontent);
}
return $content;
} else if (is_object($content)) {
debugging('Backup XML transformer should not process objects but plain content only', DEBUG_DEVELOPER);
foreach((array)$content as $key => $plaincontent) {
$content[$key] = $this->process($plaincontent);
}
return (object)$content;
}
if (is_null($content)) { // Some cases we know we can skip complete processing
return '$@NULL@$';
} else if ($content === '') {
return '';
} else if (is_numeric($content)) {
return $content;
} else if (strlen($content) < 32) { // Impossible to have one link in 32cc
return $content; // (http://10.0.0.1/file.php/1/1.jpg, http://10.0.0.1/mod/url/view.php?id=)
}
$content = $this->process_filephp_links($content); // Replace all calls to file.php by $@FILEPHP@$ in a normalised way
$content = $this->encode_absolute_links($content); // Pass the content against all the found encoders
return $content;
}
private function process_filephp_links($content) {
global $CFG;
if (strpos($content, 'file.php') === false) { // No file.php, nothing to convert
return $content;
}
//First, we check for every call to file.php inside the course
$search = array($CFG->wwwroot.'/file.php/' . $this->courseid,
$CFG->wwwroot.'/file.php?file=/' . $this->courseid,
$CFG->wwwroot.'/file.php?file=%2f' . $this->courseid,
$CFG->wwwroot.'/file.php?file=%2F' . $this->courseid);
$replace = array('$@FILEPHP@$', '$@FILEPHP@$', '$@FILEPHP@$', '$@FILEPHP@$');
$content = str_replace($search, $replace, $content);
// Now we look for any '$@FILEPHP@$' URLs, replacing:
// - slashes and %2F by $@SLASH@$
// - &forcedownload=1 &amp;forcedownload=1 and ?forcedownload=1 by $@FORCEDOWNLOAD@$
// This way, backup contents will be neutral and independent of slasharguments configuration. MDL-18799
// Based in $this->unicoderegexp, decide the regular expression to use
if ($this->unicoderegexp) { //We can use unicode modifiers
$search = '/(\$@FILEPHP@\$)((?:(?:\/|%2f|%2F))(?:(?:\([-;:@#&=\pL0-9\$~_.+!*\',]*?\))|[-;:@#&=\pL0-9\$~_.+!*\',]|%[a-fA-F0-9]{2}|\/)*)?(\?(?:(?:(?:\([-;:@#&=\pL0-9\$~_.+!*\',]*?\))|[-;:@#&=?\pL0-9\$~_.+!*\',]|%[a-fA-F0-9]{2}|\/)*))?(?<![,.;])/u';
} else { //We cannot ue unicode modifiers
$search = '/(\$@FILEPHP@\$)((?:(?:\/|%2f|%2F))(?:(?:\([-;:@#&=a-zA-Z0-9\$~_.+!*\',]*?\))|[-;:@#&=a-zA-Z0-9\$~_.+!*\',]|%[a-fA-F0-9]{2}|\/)*)?(\?(?:(?:(?:\([-;:@#&=a-zA-Z0-9\$~_.+!*\',]*?\))|[-;:@#&=?a-zA-Z0-9\$~_.+!*\',]|%[a-fA-F0-9]{2}|\/)*))?(?<![,.;])/';
}
$content = preg_replace_callback($search, array('backup_xml_transformer', 'process_filephp_uses'), $content);
return $content;
}
private function encode_absolute_links($content) {
foreach ($this->absolute_links_encoders as $classname => $methodname) {
$content = call_user_func(array($classname, $methodname), $content);
}
return $content;
}
static private function process_filephp_uses($matches) {
// Replace slashes (plain and encoded) and forcedownload=1 parameter
$search = array('/', '%2f', '%2F', '?forcedownload=1', '&forcedownload=1', '&amp;forcedownload=1');
$replace = array('$@SLASH@$', '$@SLASH@$', '$@SLASH@$', '$@FORCEDOWNLOAD@$', '$@FORCEDOWNLOAD@$', '$@FORCEDOWNLOAD@$');
$result = $matches[1] . (isset($matches[2]) ? str_replace($search, $replace, $matches[2]) : '') . (isset($matches[3]) ? str_replace($search, $replace, $matches[3]) : '');
return $result;
}
/**
* Register all available content link encoders
*
* @return array encoder
* @todo MDL-25290 replace LINKS_ENCODERS_CACHE global with MUC code
*/
private function register_link_encoders() {
global $LINKS_ENCODERS_CACHE;
// If encoder is linked, then return cached encoder.
if (!empty($LINKS_ENCODERS_CACHE)) {
return $LINKS_ENCODERS_CACHE;
}
$encoders = array();
// Add the course encoder
$encoders['backup_course_task'] = 'encode_content_links';
// Add the module ones. Each module supporting moodle2 backups MUST have it
$mods = core_component::get_plugin_list('mod');
foreach ($mods as $mod => $moddir) {
if (plugin_supports('mod', $mod, FEATURE_BACKUP_MOODLE2) && class_exists('backup_' . $mod . '_activity_task')) {
$encoders['backup_' . $mod . '_activity_task'] = 'encode_content_links';
}
}
// Add the block encoders
$blocks = core_component::get_plugin_list('block');
foreach ($blocks as $block => $blockdir) {
if (class_exists('backup_' . $block . '_block_task')) {
$encoders['backup_' . $block . '_block_task'] = 'encode_content_links';
}
}
// Add the course format encodes
// TODO: Same than blocks, need to know how courseformats are going to handle backup
// (1.9 was based in backuplib function, see code)
// Add local encodes
// TODO: Any interest? 1.9 never had that.
$LINKS_ENCODERS_CACHE = $encoders;
return $encoders;
}
}