backup/util/structure/backup_structure_processor.class.php

   1 <?php
   2
   3 // This file is part of Moodle - http://moodle.org/
   4 //
   5 // Moodle is free software: you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation, either version 3 of the License, or
   8 // (at your option) any later version.
   9 //
  10 // Moodle is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 /**
  19  * @package    moodlecore
  20  * @subpackage backup-structure
  21  * @copyright  2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  22  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  *
  24  * TODO: Finish phpdocs
  25  */
  26
  27 /**
  28  * Instantiable class defining the process of backup structures
  29  *
  30  * This class will process the given backup structure (nested/final/attribute)
  31  * based on its definition, triggering as many actions as necessary (pre/post
  32  * triggers, ids annotations, deciding based on settings, xml output...). Somehow
  33  * one visitor pattern to allow backup structures to work with nice decoupling
  34  */
  35 class backup_structure_processor extends base_processor {
  36
  37     protected $writer; // xml_writer where the processor is going to output data
  38     protected $vars;   // array of backup::VAR_XXX => helper value pairs to be used by source specifications
  39
  40     /**
  41      * @var \core\progress\base Progress tracker (null if none)
  42      */
  43     protected $progress;
  44
  45     /**
  46      * Constructor.
  47      *
  48      * @param xml_writer $writer XML writer to save data
  49      * @param c\core\progress\base$progress Progress tracker (optional)
  50      */
  51     public function __construct(xml_writer $writer, \core\progress\base $progress = null) {
  52         $this->writer = $writer;
  53         $this->progress = $progress;
  54         $this->vars = array();
  55     }
  56
  57     public function set_var($key, $value) {
  58         if (isset($this->vars[$key])) {
  59             throw new backup_processor_exception('processorvariablealreadyset', $key);
  60         }
  61         $this->vars[$key] = $value;
  62     }
  63
  64     public function get_var($key) {
  65         if (!isset($this->vars[$key])) {
  66             throw new backup_processor_exception('processorvariablenotfound', $key);
  67         }
  68         return $this->vars[$key];
  69     }
  70
  71     public function pre_process_nested_element(base_nested_element $nested) {
  72         // Send open tag to xml_writer
  73         $attrarr = array();
  74         foreach ($nested->get_attributes() as $attribute) {
  75             $attrarr[$attribute->get_name()] = $attribute->get_value();
  76         }
  77         $this->writer->begin_tag($nested->get_name(), $attrarr);
  78     }
  79
  80     public function process_nested_element(base_nested_element $nested) {
  81         // Proceed with all the file annotations for this element
  82         $fileannotations = $nested->get_file_annotations();
  83         if ($fileannotations) { // If there are areas to search
  84             $backupid  = $this->get_var(backup::VAR_BACKUPID);
  85             foreach ($fileannotations as $component => $area) {
  86                 foreach ($area as $filearea => $info) {
  87                     $contextid = !is_null($info->contextid) ? $info->contextid : $this->get_var(backup::VAR_CONTEXTID);
  88                     $itemid    = !is_null($info->element) ? $info->element->get_value() : null;
  89                     backup_structure_dbops::annotate_files($backupid, $contextid, $component, $filearea, $itemid, $this->progress);
  90                 }
  91             }
  92         }
  93     }
  94
  95     public function post_process_nested_element(base_nested_element $nested) {
  96         // Send close tag to xml_writer
  97         $this->writer->end_tag($nested->get_name());
  98         if ($this->progress) {
  99             $this->progress->progress();
 100         }
 101     }
 102
 103     public function process_final_element(base_final_element $final) {
 104         // Send full tag to xml_writer and annotations (only if has value)
 105         if ($final->is_set()) {
 106             $attrarr = array();
 107             foreach ($final->get_attributes() as $attribute) {
 108                 $attrarr[$attribute->get_name()] = $attribute->get_value();
 109             }
 110             $this->writer->full_tag($final->get_name(), $final->get_value(), $attrarr);
 111             if ($this->progress) {
 112                 $this->progress->progress();
 113             }
 114             // Annotate current value if configured to do so
 115             $final->annotate($this->get_var(backup::VAR_BACKUPID));
 116         }
 117     }
 118
 119     public function process_attribute(base_attribute $attribute) {
 120         // Annotate current value if configured to do so
 121         $attribute->annotate($this->get_var(backup::VAR_BACKUPID));
 122     }
 123 }
 124
 125 /**
 126  * backup_processor exception to control all the errors while working with backup_processors
 127  *
 128  * This exception will be thrown each time the backup_processors detects some
 129  * inconsistency related with the elements to process or its configuration
 130  */
 131 class backup_processor_exception extends base_processor_exception {
 132
 133     /**
 134      * Constructor - instantiates one backup_processor_exception
 135      *
 136      * @param string $errorcode key for the corresponding error string
 137      * @param object $a extra words and phrases that might be required in the error string
 138      * @param string $debuginfo optional debugging information
 139      */
 140     public function __construct($errorcode, $a = null, $debuginfo = null) {
 141         parent::__construct($errorcode, $a, $debuginfo);
 142     }
 143 }