Add singleton provider for evasys soap client

Author: justusdieckmann

classes/evasys_inviter.php

@@ -32,7 +32,7 @@ class evasys_inviter {
     private $soapclient;
 
     private function __construct() {
-        $this->soapclient = $this->init_soap_client();
+        $this->soapclient = evasys_soap_client::get();
     }
 
     public static function get_instance() {
@@ -259,22 +259,6 @@ public static function get_enrolled_student_email_adresses_from_usernames($moodl
         return $emailadresses;
     }
 
-    public function init_soap_client() {
-        $soapclient = new \SoapClient(get_config('block_evasys_sync', 'evasys_wsdl_url'), [
-            'trace' => 1,
-            'exceptions' => 0,
-            'location' => get_config('block_evasys_sync', 'evasys_soap_url')
-        ]);
-
-        $headerbody = new \SoapVar([
-                                       new \SoapVar(get_config('block_evasys_sync', 'evasys_username'), XSD_STRING, null, null, 'Login', null),
-                                       new \SoapVar(get_config('block_evasys_sync', 'evasys_password'), XSD_STRING, null, null, 'Password', null),
-                                   ], SOAP_ENC_OBJECT);
-        $header = new \SOAPHEADER('soap', 'Header', $headerbody);
-        $soapclient->__setSoapHeaders($header);
-        return $soapclient;
-    }
-
     public function set_close_task($surveyid) {
         $time = new \DateTime();
         $time->add(new \DateInterval("PT10S"));

classes/evasys_soap_client.php

@@ -0,0 +1,53 @@
+<?php
+// This file is part of the Moodle plugin block_evasys_sync
+//
+// 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/>.
+
+namespace block_evasys_sync;
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * Singleton for evasys soap client.
+ * @package block_evasys_sync
+ * @copyright 2022 Justus Dieckmann WWU
+ */
+class evasys_soap_client {
+
+    private static $instance = null;
+
+    public static function get(): \SoapClient {
+        if (!self::$instance) {
+            self::$instance = self::create_soap_client();
+        }
+        return self::$instance;
+    }
+
+    private static function create_soap_client(): \SoapClient {
+        $soapclient = new \SoapClient(get_config('block_evasys_sync', 'evasys_wsdl_url'), [
+            'trace' => 1,
+            'exceptions' => 0,
+            'location' => get_config('block_evasys_sync', 'evasys_soap_url')
+        ]);
+
+        $headerbody = new \SoapVar([
+            new \SoapVar(get_config('block_evasys_sync', 'evasys_username'), XSD_STRING, null, null, 'Login', null),
+            new \SoapVar(get_config('block_evasys_sync', 'evasys_password'), XSD_STRING, null, null, 'Password', null),
+        ], SOAP_ENC_OBJECT);
+        $header = new \SOAPHEADER('soap', 'Header', $headerbody);
+        $soapclient->__setSoapHeaders($header);
+        return $soapclient;
+    }
+
+}

classes/evasys_synchronizer.php

@@ -30,7 +30,7 @@ class evasys_synchronizer {
 
     public function __construct($courseid) {
         $this->courseid = $courseid;
-        $this->init_soap_client();
+        $this->soapclient = evasys_soap_client::get();
         $this->blockcontext = \context_course::instance($courseid); // TODO Course context or block context? Check caps.
         $this->courseinformation = $this->get_course_information();
     }
@@ -67,21 +67,6 @@ public function get_allocated_courses() {
         return $this->evasyscourses;
     }
 
-    private function init_soap_client() {
-        $this->soapclient = new \SoapClient(get_config('block_evasys_sync', 'evasys_wsdl_url'), [
-            'trace' => 1,
-            'exceptions' => 0,
-            'location' => get_config('block_evasys_sync', 'evasys_soap_url')
-        ]);
-
-        $headerbody = new \SoapVar([
-            new \SoapVar(get_config('block_evasys_sync', 'evasys_username'), XSD_STRING, null, null, 'Login', null),
-            new \SoapVar(get_config('block_evasys_sync', 'evasys_password'), XSD_STRING, null, null, 'Password', null),
-        ], SOAP_ENC_OBJECT);
-        $header = new \SOAPHEADER('soap', 'Header', $headerbody);
-        $this->soapclient->__setSoapHeaders($header);
-    }
-
     private function get_course_information() {
         $result = [];
         foreach ($this->get_allocated_courses() as $course) {
@@ -101,7 +86,7 @@ private function get_course_information() {
      * @return array of surveys with additional information
      */
     public function get_surveys($courseid) {
-        if ($this->courseinformation[$courseid] === null) {
+        if (!isset($this->courseinformation[$courseid]) || $this->courseinformation[$courseid] === null) {
             return array();
         }
         if (!isset($this->courseinformation[$courseid]->m_oSurveyHolder->m_aSurveys->Surveys)) {
@@ -190,7 +175,8 @@ private function get_form_name($formid) {
     }
 
     public function get_amount_participants($courseid) {
-        if ($this->courseinformation[$courseid] === null || !property_exists($this->courseinformation[$courseid]->m_aoParticipants, "Persons")) {
+        if (!isset($this->courseinformation[$courseid]) || $this->courseinformation[$courseid] === null
+            || !property_exists($this->courseinformation[$courseid]->m_aoParticipants, "Persons")) {
             return 0;
         }
         if (is_object($this->courseinformation[$courseid]->m_aoParticipants->Persons)) {