Make enrolling only LDAP users an option

lang/de/enrol_iserv.php

@@ -74,6 +74,8 @@ $string['coursemapping_prefixes_key']         = "Kurs CN Präfix";
 $string['coursemapping_prefixes_desc']            = "Ein Präfix im CN Gruppen Attribut, welches eine Gruppe als Moodle Kurs markiert. Ein * wird als Platzhalter für den restlichen CN Wert eingesetzt";
 $string['coursemapping_use_prefixes_key']         = "Kurs CN Präfix verwenden";
 $string['coursemapping_use_prefixes_desc']        = "Gibt an, ob das Kurs CN Präfix verwendet werden soll, um Gruppen Kursen zuzuweisen. Hinweis: Das Kurs Attribut hat Vorrang, wenn beide aktiv sind!";
+$string['coursemapping_map_only_ldap_users_key']  = "Kurse nur LDAP Nutzer/innen zuweisen";
+$string['coursemapping_map_only_ldap_users_desc'] = "Gibt an, ob Kurse nur Nutzer/innen zugweisen werden sollen, dessen Account via LDAP erstellt wurde";
 
 // Course Settings
 $string['courses']                          = "Kurseinstellungen";

lang/en/enrol_iserv.php

@@ -73,6 +73,8 @@ $string['coursemapping_prefixes_key']         = "Course CN Prefix";
 $string['coursemapping_prefixes_desc']            = "A prefix in the group CN attribute which marks IServ groups as Moodle courses. An asterisk (*) is used as placeholder for remaining text in the CN attribute";
 $string['coursemapping_use_prefixes_key']         = "Use course CN prefix";
 $string['coursemapping_use_prefixes_desc']        = "Specifies if the course CN prefix is used for mapping. Notice: The course attribute takes precedence when both are active!";
+$string['coursemapping_map_only_ldap_users_key']  = "Enrol only LDAP users";
+$string['coursemapping_map_only_ldap_users_desc'] = "Specifies if only those users shall be enrolled into courses, whose accounts have been created through the LDAP plugin";
 
 // Course Settings
 $string['courses']                          = "Course Settings";

lib.php

@@ -1329,13 +1329,18 @@ class enrol_iserv_plugin extends enrol_plugin
 		if (!is_array($users))
 			$users = array($users);
 
+		$user_record_filter = [];
+		if ($this->config->coursemapping_map_only_ldap_users) {
+			$user_record_filter['auth'] = 'ldap';
+		}
+
 		foreach ($users as $username) {
 			$user = $DB->get_record(
 				'user',
-				array(
-					'username' => $username,
-					'auth' => 'ldap'
-				)
+				[
+					...$user_record_filter,
+					'username' => $username
+				]
 			);
 
 			if (!$user) {
@@ -1368,13 +1373,18 @@ class enrol_iserv_plugin extends enrol_plugin
 		if (!is_array($users))
 			$users = array($users);
 
+		$user_record_filter = [];
+		if ($this->config->coursemapping_map_only_ldap_users) {
+			$user_record_filter['auth'] = 'ldap';
+		}
+
 		foreach ($users as $username) {
 			$user = $DB->get_record(
 				'user',
-				array(
-					'username' => $username,
-					'auth' => 'ldap'
-				)
+				[
+					...$user_record_filter,
+					'username' => $username
+				]
 			);
 
 			if (!$user) {

settings.php

@@ -246,6 +246,15 @@ if ($ADMIN -> fulltree) {
 		)
 	);
 
+	$settings->add(
+		new admin_setting_configcheckbox(
+			'enrol_iserv/coursemapping_map_only_ldap_users',
+			get_string('coursemapping_map_only_ldap_users_key', 'enrol_iserv'),
+			get_string('coursemapping_map_only_ldap_users_desc', 'enrol_iserv'),
+			1
+		)
+	);
+
 
 	// --- COURSES Settings --- //
 	$settings->add(