[Summary view]

   1  <?php
   2  // This file is part of Moodle - http://moodle.org/
   3  //
   4  // Moodle is free software: you can redistribute it and/or modify
   5  // it under the terms of the GNU General Public License as published by
   6  // the Free Software Foundation, either version 3 of the License, or
   7  // (at your option) any later version.
   8  //
   9  // Moodle is distributed in the hope that it will be useful,
  10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  // GNU General Public License for more details.
  13  //
  14  // You should have received a copy of the GNU General Public License
  15  // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16  
  17  /**
  18   * XML format importer class
  19   *
  20   * @package    core_dtl
  21   * @copyright  2008 Andrei Bautu
  22   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23   */
  24  
  25  defined('MOODLE_INTERNAL') || die();
  26  
  27  /**
  28   * XML format importer class (uses SAX for speed and low memory footprint).
  29   * Provides logic for parsing XML data and calling appropriate callbacks.
  30   * Subclasses should define XML data sources.
  31   */
  32  abstract class xml_database_importer extends database_importer {
  33      protected $current_table;
  34      protected $current_row;
  35      protected $current_field;
  36      protected $current_data;
  37      protected $current_data_is_null;
  38  
  39      /**
  40       * Creates and setups a SAX parser. Subclasses should use this method to
  41       * create the XML parser.
  42       *
  43       * @return resource XML parser resource.
  44       */
  45      protected function get_parser() {
  46          $parser = xml_parser_create();
  47          xml_set_object($parser, $this);
  48          xml_set_element_handler($parser, 'tag_open', 'tag_close');
  49          xml_set_character_data_handler($parser, 'cdata');
  50          xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, false);
  51          return $parser;
  52      }
  53  
  54      /**
  55       * Callback function. Called by the XML parser for opening tags processing.
  56       *
  57       * @param resource $parser XML parser resource.
  58       * @param string $tag name of opening tag
  59       * @param array $attributes set of opening tag XML attributes
  60       * @return void
  61       */
  62      protected function tag_open($parser, $tag, $attributes) {
  63          switch ($tag) {
  64              case 'moodle_database' :
  65                  if (empty($attributes['version']) || empty($attributes['timestamp'])) {
  66                      throw new dbtransfer_exception('malformedxmlexception');
  67                  }
  68                  $this->begin_database_import($attributes['version'], $attributes['timestamp']);
  69                  break;
  70              case 'table' :
  71                  if (isset($this->current_table)) {
  72                      throw new dbtransfer_exception('malformedxmlexception');
  73                  }
  74                  if (empty($attributes['name']) || empty($attributes['schemaHash'])) {
  75                      throw new dbtransfer_exception('malformedxmlexception');
  76                  }
  77                  $this->current_table = $attributes['name'];
  78                  $this->begin_table_import($this->current_table, $attributes['schemaHash']);
  79                  break;
  80              case 'record' :
  81                  if (isset($this->current_row) || !isset($this->current_table)) {
  82                      throw new dbtransfer_exception('malformedxmlexception');
  83                  }
  84                  $this->current_row = new stdClass();
  85                  break;
  86              case 'field' :
  87                  if (isset($this->current_field) || !isset($this->current_row)) {
  88                      throw new dbtransfer_exception('malformedxmlexception');
  89                  }
  90                  $this->current_field = $attributes['name'];
  91                  $this->current_data = '';
  92                  if (isset($attributes['value']) and $attributes['value'] === 'null') {
  93                      $this->current_data_is_null = true;
  94                  } else {
  95                      $this->current_data_is_null = false;
  96                  }
  97                  break;
  98              default :
  99                  throw new dbtransfer_exception('malformedxmlexception');
 100          }
 101      }
 102  
 103      /**
 104       * Callback function. Called by the XML parser for closing tags processing.
 105       *
 106       * @param resource $parser XML parser resource.
 107       * @param string $tag name of opening tag
 108       * @return void
 109       */
 110      protected function tag_close($parser, $tag) {
 111          switch ($tag) {
 112              case 'moodle_database' :
 113                  $this->finish_database_import();
 114                  break;
 115  
 116              case 'table' :
 117                  $this->finish_table_import($this->current_table);
 118                  $this->current_table = null;
 119                  break;
 120  
 121              case 'record' :
 122                  $this->import_table_data($this->current_table, $this->current_row);
 123                  $this->current_row = null;
 124                  break;
 125  
 126              case 'field' :
 127                  $field = $this->current_field;
 128                  if ($this->current_data_is_null) {
 129                      $this->current_row->$field = null;
 130                  } else {
 131                      $this->current_row->$field = $this->current_data;
 132                  }
 133                  $this->current_field        = null;
 134                  $this->current_data         = null;
 135                  $this->current_data_is_null = null;
 136                  break;
 137  
 138              default :
 139                  throw new dbtransfer_exception('malformedxmlexception');
 140          }
 141      }
 142  
 143      /**
 144       * Callback function. Called by the XML parser for character data processing.
 145       *
 146       * @param resource $parser XML parser resource.
 147       * @param string $data character data to be processed
 148       * @return void
 149       */
 150      protected function cdata($parser, $data) {
 151          if (isset($this->current_field)) {
 152              $this->current_data .= $data;
 153          }
 154      }
 155  }