MDL-77893 airnotifier: Allow configuring how to process encrypted notifs

message/output/airnotifier/classes/manager.php

@@ -37,6 +37,12 @@ class message_airnotifier_manager {
     /** @var string The Airnotifier public instance URL */
     const AIRNOTIFIER_PUBLICURL = 'https://messages.moodle.net';
 
+    /** @var int Avoid sending notifications to devices not supporting encryption */
+    const ENCRYPT_UNSUPPORTED_NOT_SEND = 0;
+
+    /** @var int Send notifications to devices not supporting encryption */
+    const ENCRYPT_UNSUPPORTED_SEND = 1;
+
     /**
      * Include the relevant javascript and language strings for the device
      * toolbox YUI module

message/output/airnotifier/lang/en/message_airnotifier.php

@@ -38,9 +38,12 @@
 $string['deletecheckdevicename'] = 'Delete your device: {$a->name}';
 $string['deletedevice'] = 'Delete the device. Note that an app can register the device again. If the device keeps reappearing, disable it.';
 $string['devicetoken'] = 'Device token';
+$string['donotsendnotification'] = 'Do not send notifications at all';
 $string['enableprocessor'] = 'Enable mobile notifications';
 $string['encryptnotifications'] = 'Encrypt notifications';
 $string['encryptnotifications_help'] = 'Enable end-to-end encryption of app notifications where possible. Only personal data is encrypted, some data may be removed from notification payload if it can\'t be encrypted.';
+$string['encryptprocessing'] = 'For devices not supporting encryption';
+$string['encryptprocessing_desc'] = 'Please indicate what to do when the target device does not support encryption (supported only Android 6 and iOS 13 onward).';
 $string['errorretrievingkey'] = 'An error occurred while retrieving the access key. Your site must be registered to use this service. If your site is already registered, please try updating your registration. Alternatively, you can obtain an access key by creating an account on the <a href="https://apps.moodle.com">Moodle Apps Portal</a>.';
 $string['keyretrievedsuccessfully'] = 'The access key was retrieved successfully. To access Moodle app usage statistics, please create an account on the <a href="https://apps.moodle.com">Moodle Apps Portal</a>.';
 $string['messageprovidersempty'] = 'There are no mobile notifications enabled in default notification preferences.';
@@ -73,6 +76,7 @@
 $string['sitemustberegistered'] = 'In order to use the public Airnotifier instance, your site must be registered. Alternatively, you can obtain an access key by creating an account on the <a href="https://apps.moodle.com">Moodle Apps Portal</a>.';
 $string['showhide'] = 'Enable/disable the device.';
 $string['requestaccesskey'] = 'Request access key';
+$string['sendnotificationnotenc'] = 'Send notifications without encryption';
 $string['sendtest'] = 'Send test push notification to my devices';
 $string['sendtestconfirmation'] = 'A test push notification will be sent to the devices you use to connect to this site. Please ensure that your devices are connected to the Internet and that the mobile app is not open (since push notifications are only displayed when received in the background).';
 $string['serverconnectivityerror'] = 'This site is not able to connect to the notifications server {$a}';

message/output/airnotifier/message_output_airnotifier.php

@@ -85,7 +85,8 @@ public function send_message($eventdata) {
         $extra->site            = $siteid;
         $extra->date            = (!empty($eventdata->timecreated)) ? $eventdata->timecreated : time();
         $extra->notification    = (!empty($eventdata->notification)) ? 1 : 0;
-        $extra->encrypted = get_config('message_airnotifier', 'encryptnotifications') == 1;
+        $encryptnotifications = get_config('message_airnotifier', 'encryptnotifications') == 1;
+        $encryptprocessing = get_config('message_airnotifier', 'encryptprocessing');
 
         // Site name.
         $site = get_site();
@@ -114,6 +115,13 @@ public function send_message($eventdata) {
                 continue;
             }
 
+            // Check if we should skip sending the notification.
+            if ($encryptnotifications && empty($devicetoken->publickey) &&
+                    $encryptprocessing == message_airnotifier_manager::ENCRYPT_UNSUPPORTED_NOT_SEND) {
+
+                continue;   // Avoid sending notifications to devices not supporting encryption.
+            }
+
             // Sending the message to the device.
             $serverurl = $CFG->airnotifierurl . ':' . $CFG->airnotifierport . '/api/v2/push/';
             $header = array('Accept: application/json', 'X-AN-APP-NAME: ' . $CFG->airnotifierappname,
@@ -123,6 +131,7 @@ public function send_message($eventdata) {
             $curl->setopt(array('CURLOPT_TIMEOUT' => 2, 'CURLOPT_CONNECTTIMEOUT' => 2));
             $curl->setHeader($header);
 
+            $extra->encrypted = $encryptnotifications;
             $extra = $this->encrypt_payload($extra, $devicetoken);
             $params = array(
                 'device'    => $devicetoken->platform,

message/output/airnotifier/settings.php

@@ -55,6 +55,19 @@
         false
     ));
 
+    $options = [
+        message_airnotifier_manager::ENCRYPT_UNSUPPORTED_NOT_SEND => new lang_string('donotsendnotification', 'message_airnotifier'),
+        message_airnotifier_manager::ENCRYPT_UNSUPPORTED_SEND => new lang_string('sendnotificationnotenc', 'message_airnotifier'),
+    ];
+    $settings->add(new admin_setting_configselect('message_airnotifier/encryptprocessing',
+        new lang_string('encryptprocessing', 'message_airnotifier'),
+        new lang_string('encryptprocessing_desc', 'message_airnotifier'),
+        message_airnotifier_manager::ENCRYPT_UNSUPPORTED_NOT_SEND,
+        $options
+    ));
+    $settings->hide_if('message_airnotifier/encryptprocessing', 'message_airnotifier/encryptnotifications',
+        'neq', 1);
+
     $url = new moodle_url('/message/output/airnotifier/requestaccesskey.php', array('sesskey' => sesskey()));
     $link = html_writer::link($url, get_string('requestaccesskey', 'message_airnotifier'));
     $settings->add(new admin_setting_heading('requestaccesskey', '', $link));