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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/>.
/**
* dataformatlib.php - Contains core dataformat related functions.
*
* @package core
* @subpackage dataformat
* @copyright 2016 Brendan Heywood (brendan@catalyst-au.net)
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
/**
* Sends a formated data file to the browser
*
* @package core
* @subpackage dataformat
*
* @param string $filename The base filename without an extension
* @param string $dataformat A dataformat name
* @param array $columns An ordered map of column keys and labels
* @param Iterator $iterator An iterator over the records, usually a RecordSet
* @param function $callback An option function applied to each record before writing
* @param mixed $extra An optional value which is passed into the callback function
*/
function download_as_dataformat($filename, $dataformat, $columns, $iterator, $callback = null) {
if (ob_get_length()) {
throw new coding_exception("Output can not be buffered before calling download_as_dataformat");
}
$classname = 'dataformat_' . $dataformat . '\writer';
if (!class_exists($classname)) {
throw new coding_exception("Unable to locate dataformat/$dataformat/classes/writer.php");
}
$format = new $classname;
// The data format export could take a while to generate...
set_time_limit(0);
// Close the session so that the users other tabs in the same session are not blocked.
\core\session\manager::write_close();
$format->set_filename($filename);
$format->send_http_headers();
// This exists to support all dataformats - see MDL-56046.
if (method_exists($format, 'write_header')) {
error_log('The function write_header() does not support multiple sheets. In order to support multiple sheets you ' .
'must implement start_output() and start_sheet() and remove write_header() in your dataformat.');
$format->write_header($columns);
} else {
$format->start_output();
$format->start_sheet($columns);
}
$c = 0;
foreach ($iterator as $row) {
if ($callback) {
$row = $callback($row);
}
if ($row === null) {
continue;
}
$format->write_record($row, $c++);
}
// This exists to support all dataformats - see MDL-56046.
if (method_exists($format, 'write_footer')) {
error_log('The function write_footer() does not support multiple sheets. In order to support multiple sheets you ' .
'must implement close_sheet() and close_output() and remove write_footer() in your dataformat.');
$format->write_footer($columns);
} else {
$format->close_sheet($columns);
$format->close_output();
}
}