Proyectos de Subversion Moodle

<?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/>.

/**

 * XML format importer class

 *

 * @package    core_dtl

 * @copyright  2008 Andrei Bautu

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

defined('MOODLE_INTERNAL') || die();

/**

 * XML format importer class (uses SAX for speed and low memory footprint).

 * Provides logic for parsing XML data and calling appropriate callbacks.

 * Subclasses should define XML data sources.

 */

abstract class xml_database_importer extends database_importer {

    protected $current_table;

    protected $current_row;

    protected $current_field;

    protected $current_data;

    protected $current_data_is_null;

    /**

     * Creates and setups a SAX parser. Subclasses should use this method to

     * create the XML parser.

     *

     * @return resource XML parser resource.

     */

    protected function get_parser() {

        $parser = xml_parser_create();

        xml_set_element_handler($parser, [$this, 'tag_open'], [$this, 'tag_close']);

        xml_set_character_data_handler($parser, [$this, 'cdata']);

        xml_parser_set_option($parser, XML_OPTION_CASE_FOLDING, false);

        return $parser;

    }

    /**

     * Callback function. Called by the XML parser for opening tags processing.

     *

     * @param resource $parser XML parser resource.

     * @param string $tag name of opening tag

     * @param array $attributes set of opening tag XML attributes

     * @return void

     */

    protected function tag_open($parser, $tag, $attributes) {

        switch ($tag) {

            case 'moodle_database' :

                if (empty($attributes['version']) || empty($attributes['timestamp'])) {

                    throw new dbtransfer_exception('malformedxmlexception');

                }

                $this->begin_database_import($attributes['version'], $attributes['timestamp']);

                break;

            case 'table' :

                if (isset($this->current_table)) {

                    throw new dbtransfer_exception('malformedxmlexception');

                }

                if (empty($attributes['name']) || empty($attributes['schemaHash'])) {

                    throw new dbtransfer_exception('malformedxmlexception');

                }

                $this->current_table = $attributes['name'];

                $this->begin_table_import($this->current_table, $attributes['schemaHash']);

                break;

            case 'record' :

                if (isset($this->current_row) || !isset($this->current_table)) {

                    throw new dbtransfer_exception('malformedxmlexception');

                }

                $this->current_row = new stdClass();

                break;

            case 'field' :

                if (isset($this->current_field) || !isset($this->current_row)) {

                    throw new dbtransfer_exception('malformedxmlexception');

                }

                $this->current_field = $attributes['name'];

                $this->current_data = '';

                if (isset($attributes['value']) and $attributes['value'] === 'null') {

                    $this->current_data_is_null = true;

                } else {

                    $this->current_data_is_null = false;

                }

                break;

            default :

                throw new dbtransfer_exception('malformedxmlexception');

        }

    }

    /**

     * Callback function. Called by the XML parser for closing tags processing.

     *

     * @param resource $parser XML parser resource.

     * @param string $tag name of opening tag

     * @return void

     */

    protected function tag_close($parser, $tag) {

        switch ($tag) {

            case 'moodle_database' :

                $this->finish_database_import();

                break;

            case 'table' :

                $this->finish_table_import($this->current_table);

                $this->current_table = null;

                break;

            case 'record' :

                $this->import_table_data($this->current_table, $this->current_row);

                $this->current_row = null;

                break;

            case 'field' :

                $field = $this->current_field;

                if ($this->current_data_is_null) {

                    $this->current_row->$field = null;

                } else {

                    $this->current_row->$field = $this->current_data;

                }

                $this->current_field        = null;

                $this->current_data         = null;

                $this->current_data_is_null = null;

                break;

            default :

                throw new dbtransfer_exception('malformedxmlexception');

        }

    }

    /**

     * Callback function. Called by the XML parser for character data processing.

     *

     * @param resource $parser XML parser resource.

     * @param string $data character data to be processed

     * @return void

     */

    protected function cdata($parser, $data) {

        if (isset($this->current_field)) {

            $this->current_data .= $data;

        }

    }

}