Generating Emails in Moodle...

emailpreview.php

<?php
//Preview an email

require_once("../../../../config.php");

require_once($CFG->dirroot . '/mod/assign/locallib.php');

$ex =\assignsubmission_strathfm\local\model\extension_request::get_record(['id' => 11]);

$u = core_user::get_user($ex->get('userid'));
$u = $USER;

$config = \assignsubmission_strathfm\local\helper::get_config();

$emaildata = new \assignsubmission_strathfm\output\extensionrequest_email($ex, $u, $config);


$o = $PAGE->get_renderer('core');

//print_r($emaildata->export_for_template($o));

//echo $OUTPUT->render_from_template('assignsubmission_strathfm/extensionrequest_receipt_html', $emaildata->export_for_template($o));
echo $OUTPUT->render_from_template('assignsubmission_strathfm/extensionrequest_new_request_notification', $emaildata->export_for_template($o));

extensionrequest_email.php

<?php

namespace assignsubmission_strathfm\output;

use assignsubmission_strathfm\local\exporter\extension_request_exporter;
use assignsubmission_strathfm\local\model\extension_request;
use renderer_base;
use assignsubmission_strathfm\local\helper;
use report_groups\export\export;
use stdClass;
use assignsubmission_strathfm\extension_form;

/**
 * Class extensionrequest_email
 * @package assignsubmission_strathfm\output
 *
 * Holds all of the information required to email a user (staff or student)
 * about an extension.
 */
class extensionrequest_email implements \renderable, \templatable
{

    private $_request;
    private $_recipient;
    private $_config;
    private $_extensioninfo;
    private $_course;
    private $_cm;
    /**
     * extensionrequest_email constructor.
     * @param extension_request $request Request record
     * @param \stdClass $decision Decision record
     */
    public function __construct(
        $request,
        $recipient,
        $config
    ) {
        $this->_request = $request;
        $this->_recipient = $recipient;
        $this->_config = $config;

        list($course, $cm) = get_course_and_cm_from_cmid($request->get('cmid'));
        $this->_course = $course;
        $this->_cm = $cm;
        $context = $cm->context;
        $this->_extensioninfo = helper::get_extension_info($context);
    }

    public function export_for_template(renderer_base $output)
    {
        $requester = \core_user::get_user($this->_request->get('userid'));
        $data = [];
        $data['recipient_fullname'] = fullname($this->_recipient);
        foreach($this->_recipient as $property=>$value) {
            $data['recipient_'.$property] = $value;
        }

        $rqe = new extension_request_exporter($this->_request);
        $rq = $rqe->export($output);
        foreach($rq as $property=>$value) {
            $data["extension_". $property] = $value;
        }
        $data['extension_userfullname'] = fullname($requester) ?? "";
        $data['extension_coursefullname'] = $this->course->fullname ?? "";
        $data['extension_cmurl'] = $this->_cm->url ?? "";
        $data['extension_activitylink'] = $output->action_link(
            $this->_cm->url, $this->_cm->name
        );
        $data['extension_managelink'] = $output->action_link(
            new \moodle_url('/mod/assign/submission/strathfm/manage.php', ['id' => $this->_cm->id]),
            get_string('activityextensions', 'assignsubmission_strathfm', $this->_cm->name)
        );
        $data['extension_managethislink'] = $output->action_link(
            new \moodle_url('/mod/assign/submission/strathfm/manage.php', ['id' => $this->_cm->id, 'extid' => $this->_request->get('id')]),
            get_string('userextensionrequest', 'assignsubmission_strathfm', $data['extension_userfullname'])
        );

        foreach($this->_config as $property=>$value) {
            $data["config_". $property] = $value;
        }
        foreach($this->_extensioninfo as $property=>$value) {
            $data["info_". $property] = $value;
        }
        $data['info_warninterval_readable'] = helper::elapsed_time($data['info_warninterval']);
        $data['info_criticalinterval_readable'] = helper::elapsed_time($data['info_criticalinterval']);
        return (object)$data;
    }
}

extensionrequest_new_request_notification.mustache

{{!
    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/>.
}}
{{!
    @template assignsubmission_strathfm/extensionrequest_receipt_html

    Generates HTML email for notifying staff about a new request

    Classes required for JS:
    * none

    Data attributes required for JS:
    * none

    Context variables required for this template:
}}

<div>{{#str}}dearuser, assignsubmission_strathfm, {{recipient_fullname}}{{/str}}</div>
<div>{{#str}}emailrequestcreatednotification, assignsubmission_strathfm,
    {
        "extension_userfullname": "{{extension_userfullname}}",
        "extension_activitylink": {{#quote}}{{{extension_activitylink}}}{{/quote}},
        "info_warninterval_readable": {{#quote}}{{info_warninterval_readable}}{{/quote}},
        "info_criticalinterval_readable": {{#quote}}{{info_criticalinterval_readable}}{{/quote}},
        "extension_managethislink": {{#quote}}{{{extension_managethislink}}}{{/quote}},
        "extension_managelink": {{#quote}}{{{extension_managelink}}}{{/quote}}
    }
    {{/str}}</div>
<div>{{#str}}contactinfo, assignsubmission_strathfm, {{{info_contact}}}{{/str}}</div>

strings_file.php

$string['emailrequestcreatedrecipt'] = 'Your request has been submitted for review.';
$string['emailrequestcreatednotification'] = '<p>{$a->extension_userfullname} has submitted a request for an
extension or exceptional circumstances for {$a->extension_activitylink}.</p>
<p>This request will be marked as "warn" after {$a->info_warninterval_readable} and as "critical" after {$a->info_criticalinterval_readable}.</p>
<p>You can action this request by going to {$a->extension_managethislink}.</p>
<p>You can access the list of requests for this activity by going to {$a->extension_managelink}.</p> 
';