export.php

<?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/>.

use block_exacomp\data;

require __DIR__ . '/inc.php';

$courseid = required_param('courseid', PARAM_INT);

if (!$course = $DB->get_record('course', array('id' => $courseid))) {
    print_error('invalidcourse', 'block_simplehtml', $courseid);
}

block_exacomp_require_login($course);

$course_context = context_course::instance($courseid);

require_capability('block/exacomp:admin', context_system::instance());

$action = required_param('action', PARAM_ALPHANUMEXT);

$output = block_exacomp_get_renderer();

data::prepare();

function block_exacomp_require_secret() {
    global $PAGE, $courseid;

    // zip encoding only available from php 7.2 on
    $needsSecret = get_config('exacomp', 'export_password') && (version_compare(phpversion(), '7.2') >= 0);
    if (!$needsSecret) {
        // no secret needed
        return '';
    }

    $secret = optional_param('secret', 0, PARAM_TEXT);

    if ($secret) {
        return $secret;
    }

    $secret = block_exacomp_random_password();

    $output = block_exacomp_get_renderer();

    /* PAGE IDENTIFIER - MUST BE CHANGED. Please use string identifier from lang file */
    $page_identifier = 'tab_admin_import';

    /* PAGE URL - MUST BE CHANGED */
    $PAGE->set_url('/blocks/exacomp/export.php', array('courseid' => $courseid));
    $PAGE->set_heading(block_exacomp_get_string('blocktitle'));
    $PAGE->set_title(block_exacomp_get_string($page_identifier));

    // build breadcrumbs navigation
    $coursenode = $PAGE->navigation->find($courseid, navigation_node::TYPE_COURSE);
    $blocknode = $coursenode->add(block_exacomp_get_string('blocktitle'));
    $pagenode = $blocknode->add(block_exacomp_get_string($page_identifier), $PAGE->url);
    $pagenode->make_active();

    echo $output->header(context_system::instance(), $courseid, 'tab_admin_settings');
    echo $output->tabtree(block_exacomp_build_navigation_tabs_admin_settings($courseid), $page_identifier);

    echo block_exacomp_get_string('export_password_message', null, $secret);
    echo '<br/><br/>';

    // add all other post parameters, eg. descriptors[], subjects[], topics[]
    $flatten_params = function($params, $level = 0) use (&$flatten_params) {
        $ret = [];
        foreach ($params as $key => $value) {
            $key = clean_param($key, PARAM_TEXT);
            $key = $level > 0 ? '[' . $key . ']' : $key;
            if (is_array($value)) {
                foreach ($flatten_params($value, $level + 1) as $subKey => $value) {
                    $ret[$key . $subKey] = $value;
                }
            } else {
                $value = clean_param($value, PARAM_TEXT);
                $ret[$key] = $value;
            }
        }
        return $ret;
    };

    $other_params = '';
    foreach ($flatten_params($_POST) as $key => $value) {
        $other_params .= '<input type="hidden" name="' . $key . '" value="' . $value . '" />';
    }

    echo '<form method="post">
		' . $other_params . '
		<input type="hidden" name="secret" value="' . $secret . '" />
		<input type="hidden" name="sesskey" value="' . sesskey() . '" />
		<input type="submit" class="btn btn-primary" value="' . block_exacomp_get_string('next') . '" />
	</form>';

    echo $output->footer();
    exit;
}

if ($action == 'export_all') {
    require_sesskey();
    $secret = block_exacomp_require_secret();

    block_exacomp\data_exporter::do_export($secret);
} else if ($action == 'export_selected') {
    require_sesskey();
    $secret = block_exacomp_require_secret();
    $descriptors = block_exacomp\param::optional_array('descriptors', array(PARAM_INT => PARAM_INT));

    block_exacomp\data_exporter::do_export($secret, $descriptors);
} else if ($action == 'select') {

    /* PAGE IDENTIFIER - MUST BE CHANGED. Please use string identifier from lang file */
    $page_identifier = 'tab_admin_import';

    /* PAGE URL - MUST BE CHANGED */
    $PAGE->set_url('/blocks/exacomp/export.php', array('courseid' => $courseid, 'sesskey' => sesskey()));
    $PAGE->set_heading(block_exacomp_get_string('blocktitle'));
    $PAGE->set_title(block_exacomp_get_string($page_identifier));

    // build breadcrumbs navigation
    $coursenode = $PAGE->navigation->find($courseid, navigation_node::TYPE_COURSE);
    $blocknode = $coursenode->add(block_exacomp_get_string('blocktitle'));
    $pagenode = $blocknode->add(block_exacomp_get_string($page_identifier), $PAGE->url);
    $pagenode->make_active();

    echo $output->header(context_system::instance(), $courseid, 'tab_admin_settings');
    echo $OUTPUT->tabtree(block_exacomp_build_navigation_tabs_admin_settings($courseid), $page_identifier);

    echo $output->descriptor_selection_export();

    echo $output->footer();
} else {
    print_error("wrong action '$action'");
}