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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/>.
/**
* @package moodlecore
* @subpackage backup-helper
* @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();
/**
* Helper class used to decode links back to their original form
*
* This class allows each restore task to specify the changes that
* will be applied to any encoded (by backup) link to revert it back
* to its original form, recoding any parameter as needed.
*
* TODO: Complete phpdocs
*/
class restore_decode_rule {
protected $linkname; // How the link has been encoded in backup (CHOICEVIEWBYID, COURSEVIEWBYID...)
protected $urltemplate; // How the original URL looks like, with dollar placeholders
protected $mappings; // Which backup_ids mappings do we need to apply for replacing the placeholders
protected $restoreid; // The unique restoreid we are executing
protected $sourcewwwroot; // The original wwwroot of the backup file
protected $targetwwwroot; // The targer wwwroot of the restore operation
protected $cregexp; // Calculated regular expresion we'll be looking for matches
public function __construct($linkname, $urltemplate, $mappings) {
// Validate all the params are ok
$this->mappings = $this->validate_params($linkname, $urltemplate, $mappings);
$this->linkname = $linkname;
$this->urltemplate = $urltemplate;
$this->restoreid = 0;
$this->sourcewwwroot = '';
$this->targetwwwroot = ''; // yes, uses to be $CFG->wwwroot, and? ;-)
$this->cregexp = $this->get_calculated_regexp();
}
public function set_restoreid($restoreid) {
$this->restoreid = $restoreid;
}
public function set_wwwroots($sourcewwwroot, $targetwwwroot) {
$this->sourcewwwroot = $sourcewwwroot;
$this->targetwwwroot = $targetwwwroot;
}
public function decode($content) {
if (preg_match_all($this->cregexp, $content, $matches) === 0) { // 0 matches, nothing to change
return $content;
}
// Have found matches, iterate over them
foreach ($matches[0] as $key => $tosearch) {
$mappingsok = true; // To detect if any mapping has failed
$placeholdersarr = array(); // The placeholders to be replaced
$mappingssourcearr = array(); // To store the original mappings values
$mappingstargetarr = array(); // To store the target mappings values
$toreplace = $this->urltemplate;// The template used to build the replacement
foreach ($this->mappings as $mappingkey => $mappingsource) {
$source = $matches[$mappingkey][$key]; // get source
$mappingssourcearr[$mappingkey] = $source; // set source arr
$mappingstargetarr[$mappingkey] = 0; // apply default mapping
$placeholdersarr[$mappingkey] = '$'.$mappingkey;// set the placeholders arr
if (!$mappingsok) { // already missing some mapping, continue
continue;
}
if (!$target = $this->get_mapping($mappingsource, $source)) {// mapping not found, mark and continue
$mappingsok = false;
continue;
}
$mappingstargetarr[$mappingkey] = $target; // store found mapping
}
$toreplace = $this->apply_modifications($toreplace, $mappingsok); // Apply other changes before replacement
if (!$mappingsok) { // Some mapping has failed, apply original values to the template
$toreplace = str_replace($placeholdersarr, $mappingssourcearr, $toreplace);
} else { // All mappings found, apply target values to the template
$toreplace = str_replace($placeholdersarr, $mappingstargetarr, $toreplace);
}
// Finally, perform the replacement in original content
$content = str_replace($tosearch, $toreplace, $content);
}
return $content; // return the decoded content, pointing to original or target values
}
// Protected API starts here
/**
* Looks for mapping values in backup_ids table, simple wrapper over get_backup_ids_record
*/
protected function get_mapping($itemname, $itemid) {
// Check restoreid is set
if (!$this->restoreid) {
throw new restore_decode_rule_exception('decode_rule_restoreid_not_set');
}
if (!$found = restore_dbops::get_backup_ids_record($this->restoreid, $itemname, $itemid)) {
return false;
}
return $found->newitemid;
}
/**
* Apply other modifications, based in the result of $mappingsok before placeholder replacements
*
* Right now, simply prefix with the proper wwwroot (source/target)
*/
protected function apply_modifications($toreplace, $mappingsok) {
// Check wwwroots are set
if (!$this->targetwwwroot || !$this->sourcewwwroot) {
throw new restore_decode_rule_exception('decode_rule_wwwroots_not_set');
}
return ($mappingsok ? $this->targetwwwroot : $this->sourcewwwroot) . $toreplace;
}
/**
* Perform all the validations and checks on the rule attributes
*/
protected function validate_params($linkname, $urltemplate, $mappings) {
// Check linkname is A-Z0-9
if (empty($linkname) || preg_match('/[^A-Z0-9]/', $linkname)) {
throw new restore_decode_rule_exception('decode_rule_incorrect_name', $linkname);
}
// Look urltemplate starts by /
if (empty($urltemplate) || substr($urltemplate, 0, 1) != '/') {
throw new restore_decode_rule_exception('decode_rule_incorrect_urltemplate', $urltemplate);
}
if (!is_array($mappings)) {
$mappings = array($mappings);
}
// Look for placeholders in template
$countph = preg_match_all('/(\$\d+)/', $urltemplate, $matches);
$countma = count($mappings);
// Check mappings number matches placeholders
if ($countph != $countma) {
$a = new stdClass();
$a->placeholders = $countph;
$a->mappings = $countma;
throw new restore_decode_rule_exception('decode_rule_mappings_incorrect_count', $a);
}
// Verify they are consecutive (starting on 1)
$smatches = str_replace('$', '', $matches[1]);
sort($smatches, SORT_NUMERIC);
if (reset($smatches) != 1 || end($smatches) != $countma) {
throw new restore_decode_rule_exception('decode_rule_nonconsecutive_placeholders', implode(', ', $smatches));
}
// No dupes in placeholders
if (count($smatches) != count(array_unique($smatches))) {
throw new restore_decode_rule_exception('decode_rule_duplicate_placeholders', implode(', ', $smatches));
}
// Return one array of placeholders as keys and mappings as values
return array_combine($smatches, $mappings);
}
/**
* based on rule definition, build the regular expression to execute on decode
*/
protected function get_calculated_regexp() {
$regexp = '/\$@' . $this->linkname;
foreach ($this->mappings as $key => $value) {
$regexp .= '\*(\d+)';
}
$regexp .= '@\$/';
return $regexp;
}
}
/*
* Exception class used by all the @restore_decode_rule stuff
*/
class restore_decode_rule_exception extends backup_exception {
public function __construct($errorcode, $a=NULL, $debuginfo=null) {
return parent::__construct($errorcode, $a, $debuginfo);
}
}