Merge branch 'MDL-55956-master-5' of git://github.com/junpataleta/moodle

calendar/lib.php

@@ -120,6 +120,11 @@ define('CALENDAR_SUBSCRIPTION_UPDATE', 1);
  */
 define('CALENDAR_SUBSCRIPTION_REMOVE', 2);
 
+/**
+ * CALENDAR_EVENT_USER_OVERRIDE_PRIORITY - Constant for the user override priority.
+ */
+define('CALENDAR_EVENT_USER_OVERRIDE_PRIORITY', 9999999);
+
 /**
  * Return the days of the week
  *
@@ -723,85 +728,164 @@ function calendar_add_event_metadata($event) {
  * @param boolean $ignorehidden whether to select only visible events or all events
  * @return array $events of selected events or an empty array if there aren't any (or there was an error)
  */
-function calendar_get_events($tstart, $tend, $users, $groups, $courses, $withduration=true, $ignorehidden=true) {
+function calendar_get_events($tstart, $tend, $users, $groups, $courses, $withduration = true, $ignorehidden = true) {
     global $DB;
 
-    $whereclause = '';
     $params = array();
     // Quick test.
     if (empty($users) && empty($groups) && empty($courses)) {
         return array();
     }
 
+    // Array of filter conditions. To be concatenated by the OR operator.
+    $filters = [];
+
+    // User filter.
     if ((is_array($users) && !empty($users)) or is_numeric($users)) {
         // Events from a number of users
-        if(!empty($whereclause)) $whereclause .= ' OR';
         list($insqlusers, $inparamsusers) = $DB->get_in_or_equal($users, SQL_PARAMS_NAMED);
-        $whereclause .= " (e.userid $insqlusers AND e.courseid = 0 AND e.groupid = 0)";
+        $filters[] = "(e.userid $insqlusers AND e.courseid = 0 AND e.groupid = 0)";
         $params = array_merge($params, $inparamsusers);
-    } else if($users === true) {
+    } else if ($users === true) {
         // Events from ALL users
-        if(!empty($whereclause)) $whereclause .= ' OR';
+        $filters[] = "(e.userid != 0 AND e.courseid = 0 AND e.groupid = 0)";
-        $whereclause .= ' (e.userid != 0 AND e.courseid = 0 AND e.groupid = 0)';
-    } else if($users === false) {
-        // No user at all, do nothing
     }
+    // Boolean false (no users at all): We don't need to do anything.
 
+    // Group filter.
     if ((is_array($groups) && !empty($groups)) or is_numeric($groups)) {
         // Events from a number of groups
-        if(!empty($whereclause)) $whereclause .= ' OR';
         list($insqlgroups, $inparamsgroups) = $DB->get_in_or_equal($groups, SQL_PARAMS_NAMED);
-        $whereclause .= " e.groupid $insqlgroups ";
+        $filters[] = "e.groupid $insqlgroups";
         $params = array_merge($params, $inparamsgroups);
-    } else if($groups === true) {
+    } else if ($groups === true) {
         // Events from ALL groups
-        if(!empty($whereclause)) $whereclause .= ' OR ';
+        $filters[] = "e.groupid != 0";
-        $whereclause .= ' e.groupid != 0';
     }
-    // boolean false (no groups at all): we don't need to do anything
+    // Boolean false (no groups at all): We don't need to do anything.
 
+    // Course filter.
     if ((is_array($courses) && !empty($courses)) or is_numeric($courses)) {
-        if(!empty($whereclause)) $whereclause .= ' OR';
         list($insqlcourses, $inparamscourses) = $DB->get_in_or_equal($courses, SQL_PARAMS_NAMED);
-        $whereclause .= " (e.groupid = 0 AND e.courseid $insqlcourses)";
+        $filters[] = "(e.groupid = 0 AND e.courseid $insqlcourses)";
         $params = array_merge($params, $inparamscourses);
     } else if ($courses === true) {
         // Events from ALL courses
-        if(!empty($whereclause)) $whereclause .= ' OR';
+        $filters[] = "(e.groupid = 0 AND e.courseid != 0)";
-        $whereclause .= ' (e.groupid = 0 AND e.courseid != 0)';
     }
 
     // Security check: if, by now, we have NOTHING in $whereclause, then it means
     // that NO event-selecting clauses were defined. Thus, we won't be returning ANY
     // events no matter what. Allowing the code to proceed might return a completely
     // valid query with only time constraints, thus selecting ALL events in that time frame!
-    if(empty($whereclause)) {
+    if (empty($filters)) {
         return array();
     }
 
-    if($withduration) {
+    // Build our clause for the filters.
-        $timeclause = '(e.timestart >= '.$tstart.' OR e.timestart + e.timeduration > '.$tstart.') AND e.timestart <= '.$tend;
+    $filterclause = implode(' OR ', $filters);
-    }
-    else {
-        $timeclause = 'e.timestart >= '.$tstart.' AND e.timestart <= '.$tend;
-    }
-    if(!empty($whereclause)) {
-        // We have additional constraints
-        $whereclause = $timeclause.' AND ('.$whereclause.')';
-    }
-    else {
-        // Just basic time filtering
-        $whereclause = $timeclause;
-    }
 
+    // Array of where conditions for our query. To be concatenated by the AND operator.
+    $whereconditions = ["($filterclause)"];
+
+    // Time clause.
+    if ($withduration) {
+        $timeclause = "((e.timestart >= :tstart1 OR e.timestart + e.timeduration > :tstart2) AND e.timestart <= :tend)";
+        $params['tstart1'] = $tstart;
+        $params['tstart2'] = $tstart;
+        $params['tend'] = $tend;
+    } else {
+        $timeclause = "(e.timestart >= :tstart AND e.timestart <= :tend)";
+        $params['tstart'] = $tstart;
+        $params['tend'] = $tend;
+    }
+    $whereconditions[] = $timeclause;
+
+    // Show visible only.
     if ($ignorehidden) {
-        $whereclause .= ' AND e.visible = 1';
+        $whereconditions[] = "(e.visible = 1)";
     }
 
+    // Build the main query's WHERE clause.
+    $whereclause = implode(' AND ', $whereconditions);
+
+    // Build SQL subquery and conditions for filtered events based on priorities.
+    $subquerywhere = '';
+    $subqueryconditions = [];
+
+    // Get the user's courses. Otherwise, get the default courses being shown by the calendar.
+    $usercourses = calendar_get_default_courses();
+
+    // Set calendar filters.
+    list($usercourses, $usergroups, $user) = calendar_set_filters($usercourses, true);
+    $subqueryparams = [];
+
+    // Flag to indicate whether the query needs to exclude group overrides.
+    $viewgroupsonly = false;
+
+    if ($user) {
+        // Set filter condition for the user's events.
+        $subqueryconditions[] = "(ev.userid = :user AND ev.courseid = 0 AND ev.groupid = 0)";
+        $subqueryparams['user'] = $user;
+
+        foreach ($usercourses as $courseid) {
+            if (has_capability('moodle/site:accessallgroups', context_course::instance($courseid))) {
+                $usergroupmembership = groups_get_all_groups($courseid, $user, 0, 'g.id');
+                if (count($usergroupmembership) == 0) {
+                    $viewgroupsonly = true;
+                    break;
+                }
+            }
+        }
+    }
+
+    // Set filter condition for the user's group events.
+    if ($usergroups === true || $viewgroupsonly) {
+        // Fetch group events, but not group overrides.
+        $subqueryconditions[] = "(ev.groupid != 0 AND ev.eventtype = 'group')";
+    } else if (!empty($usergroups)) {
+        // Fetch group events and group overrides.
+        list($inusergroups, $inusergroupparams) = $DB->get_in_or_equal($usergroups, SQL_PARAMS_NAMED);
+        $subqueryconditions[] = "(ev.groupid $inusergroups)";
+        $subqueryparams = array_merge($subqueryparams, $inusergroupparams);
+    }
+
+    // Set filter condition for the user's courses.
+    if (!empty($usercourses)) {
+        list($inusercourses, $inusercoursesparams) = $DB->get_in_or_equal($usercourses, SQL_PARAMS_NAMED);
+        $subqueryconditions[] = "(ev.groupid = 0 AND ev.courseid $inusercourses)";
+        $subqueryparams = array_merge($subqueryparams, $inusercoursesparams);
+    }
+
+    // Build the WHERE condition for the sub-query.
+    if (!empty($subqueryconditions)) {
+        $subquerywhere = 'WHERE ' . implode(" OR ", $subqueryconditions);
+    }
+
+    // Merge subquery parameters to the parameters of the main query.
+    if (!empty($subqueryparams)) {
+        $params = array_merge($params, $subqueryparams);
+    }
+
+    // Sub-query that fetches the list of unique events that were filtered based on priority.
+    $subquery = "SELECT ev.modulename,
+                        ev.instance,
+                        ev.eventtype,
+                        MAX(ev.priority) as priority
+                   FROM {event} ev
+                  $subquerywhere
+               GROUP BY ev.modulename, ev.instance, ev.eventtype";
+
+    // Build the main query.
     $sql = "SELECT e.*
               FROM {event} e
-         LEFT JOIN {modules} m ON e.modulename = m.name
+        INNER JOIN ($subquery) fe
-                -- Non visible modules will have a value of 0.
+                ON e.modulename = fe.modulename
+                   AND e.instance = fe.instance
+                   AND e.eventtype = fe.eventtype
+                   AND (e.priority = fe.priority OR (e.priority IS NULL AND fe.priority IS NULL))
+         LEFT JOIN {modules} m
+                ON e.modulename = m.name
              WHERE (m.visible = 1 OR m.visible IS NULL) AND $whereclause
           ORDER BY e.timestart";
     $events = $DB->get_records_sql($sql, $params);

calendar/tests/externallib_test.php

@@ -62,7 +62,7 @@ class core_calendar_externallib_testcase extends externallib_advanced_testcase {
      */
 
     public static function create_calendar_event($name, $userid = 0, $type = 'user', $repeats = 0, $timestart  = null, $prop = null) {
-        global $CFG, $DB, $USER, $SITE;
+        global $CFG, $DB, $SITE;
 
         require_once("$CFG->dirroot/calendar/lib.php");
         if (!empty($prop)) {
@@ -100,6 +100,26 @@ class core_calendar_externallib_testcase extends externallib_advanced_testcase {
         if (!isset($prop->courseid)) {
             $prop->courseid = $SITE->id;
         }
+
+        // Determine event priority.
+        if ($prop->courseid == 0 && isset($prop->groupid) && $prop->groupid == 0 && !empty($prop->userid)) {
+            // User override event.
+            $prop->priority = CALENDAR_EVENT_USER_OVERRIDE_PRIORITY;
+        } else if ($prop->courseid != $SITE->id && !empty($prop->groupid)) {
+            // Group override event.
+            $priorityparams = ['courseid' => $prop->courseid, 'groupid' => $prop->groupid];
+            // Group override event with the highest priority.
+            $groupevents = $DB->get_records('event', $priorityparams, 'priority DESC', 'id, priority', 0, 1);
+            $priority = 1;
+            if (!empty($groupevents)) {
+                $event = reset($groupevents);
+                if (!empty($event->priority)) {
+                    $priority = $event->priority + 1;
+                }
+            }
+            $prop->priority = $priority;
+        }
+
         $event = new calendar_event($prop);
         return $event->create($prop);
     }
@@ -266,6 +286,7 @@ class core_calendar_externallib_testcase extends externallib_advanced_testcase {
         global $DB, $USER;
 
         $this->resetAfterTest(true);
+        set_config('calendar_adminseesall', 1);
         $this->setAdminUser();
 
         // Create a few stuff to test with.
@@ -296,13 +317,19 @@ class core_calendar_externallib_testcase extends externallib_advanced_testcase {
 
         $record = new stdClass();
         $record->courseid = $course->id;
+        $record->groupid = 0;
         $record->description = array(
             'format' => FORMAT_HTML,
             'text' => 'Text with img <img src="@@PLUGINFILE@@/fakeimage.png">',
             'itemid' => $draftidfile
         );
         $courseevent = $this->create_calendar_event('course', $USER->id, 'course', 2, time(), $record);
-        $userevent = $this->create_calendar_event('user', $USER->id);
+
+        $record = new stdClass();
+        $record->courseid = 0;
+        $record->groupid = 0;
+        $userevent = $this->create_calendar_event('user', $USER->id, 'user', 0, time(), $record);
+
         $record = new stdClass();
         $record->courseid = $course->id;
         $record->groupid = $group->id;
@@ -335,6 +362,13 @@ class core_calendar_externallib_testcase extends externallib_advanced_testcase {
         $this->assertEquals(2, $withdescription);
 
         // Let's play around with caps.
+
+        // Create user event for the user $user.
+        $record = new stdClass();
+        $record->courseid = 0;
+        $record->groupid = 0;
+        $this->create_calendar_event('user', $user->id, 'user', 0, time(), $record);
+
         $this->setUser($user);
         $events = core_calendar_external::get_calendar_events($paramevents, $options);
         $events = external_api::clean_returnvalue(core_calendar_external::get_calendar_events_returns(), $events);

calendar/tests/lib_test.php

@@ -119,35 +119,42 @@ class core_calendar_lib_testcase extends advanced_testcase {
     public function test_calendar_get_events_with_disabled_module() {
         global $DB;
 
-        $course = $this->getDataGenerator()->create_course();
+        $generator = $this->getDataGenerator();
-        $events = [[
+        $course = $generator->create_course();
-                        'name' => 'Start of assignment',
+        $student = $generator->create_user();
-                        'description' => '',
+        $generator->enrol_user($student->id, $course->id, 'student');
-                        'format' => 1,
+        $this->setUser($student);
-                        'courseid' => $course->id,
+
-                        'groupid' => 0,
+        $events = [
-                        'userid' => 2,
+            [
-                        'modulename' => 'assign',
+                'name' => 'Start of assignment',
-                        'instance' => 1,
+                'description' => '',
-                        'eventtype' => 'due',
+                'format' => 1,
-                        'timestart' => time(),
+                'courseid' => $course->id,
-                        'timeduration' => 86400,
+                'groupid' => 0,
-                        'visible' => 1
+                'userid' => 2,
-                    ], [
+                'modulename' => 'assign',
-                        'name' => 'Start of lesson',
+                'instance' => 1,
-                        'description' => '',
+                'eventtype' => 'due',
-                        'format' => 1,
+                'timestart' => time(),
-                        'courseid' => $course->id,
+                'timeduration' => 86400,
-                        'groupid' => 0,
+                'visible' => 1
-                        'userid' => 2,
+            ], [
-                        'modulename' => 'lesson',
+
-                        'instance' => 1,
+                'name' => 'Start of lesson',
-                        'eventtype' => 'end',
+                'description' => '',
-                        'timestart' => time(),
+                'format' => 1,
-                        'timeduration' => 86400,
+                'courseid' => $course->id,
-                        'visible' => 1
+                'groupid' => 0,
-                    ]
+                'userid' => 2,
-                ];
+                'modulename' => 'lesson',
+                'instance' => 1,
+                'eventtype' => 'end',
+                'timestart' => time(),
+                'timeduration' => 86400,
+                'visible' => 1
+            ]
+        ];
 
         foreach ($events as $event) {
             calendar_event::create($event, false);
@@ -171,4 +178,186 @@ class core_calendar_lib_testcase extends advanced_testcase {
         $event = reset($events);
         $this->assertEquals('assign', $event->modulename);
     }
+
+    /**
+     * Test for calendar_get_events() when there are user and group overrides.
+     */
+    public function test_calendar_get_events_with_overrides() {
+        global $DB;
+
+        $generator = $this->getDataGenerator();
+        $course = $generator->create_course();
+        $plugingenerator = $this->getDataGenerator()->get_plugin_generator('mod_assign');
+        if (!isset($params['course'])) {
+            $params['course'] = $course->id;
+        }
+        $instance = $plugingenerator->create_instance($params);
+
+        // Create users.
+        $useroverridestudent = $generator->create_user();
+        $group1student = $generator->create_user();
+        $group2student = $generator->create_user();
+        $group12student = $generator->create_user();
+        $nogroupstudent = $generator->create_user();
+
+        // Enrol users.
+        $generator->enrol_user($useroverridestudent->id, $course->id, 'student');
+        $generator->enrol_user($group1student->id, $course->id, 'student');
+        $generator->enrol_user($group2student->id, $course->id, 'student');
+        $generator->enrol_user($group12student->id, $course->id, 'student');
+        $generator->enrol_user($nogroupstudent->id, $course->id, 'student');
+
+        // Create groups.
+        $group1 = $generator->create_group(['courseid' => $course->id]);
+        $group2 = $generator->create_group(['courseid' => $course->id]);
+
+        // Add members to groups.
+        $generator->create_group_member(['groupid' => $group1->id, 'userid' => $group1student->id]);
+        $generator->create_group_member(['groupid' => $group2->id, 'userid' => $group2student->id]);
+        $generator->create_group_member(['groupid' => $group1->id, 'userid' => $group12student->id]);
+        $generator->create_group_member(['groupid' => $group2->id, 'userid' => $group12student->id]);
+
+        $now = time();
+        // Events with the same module name, instance and event type.
+        $events = [
+            [
+                'name' => 'Assignment 1 due date',
+                'description' => '',
+                'format' => 0,
+                'courseid' => $course->id,
+                'groupid' => 0,
+                'userid' => 2,
+                'modulename' => 'assign',
+                'instance' => $instance->id,
+                'eventtype' => 'due',
+                'timestart' => $now,
+                'timeduration' => 0,
+                'visible' => 1
+            ], [
+                'name' => 'Assignment 1 due date - User override',
+                'description' => '',
+                'format' => 1,
+                'courseid' => 0,
+                'groupid' => 0,
+                'userid' => $useroverridestudent->id,
+                'modulename' => 'assign',
+                'instance' => $instance->id,
+                'eventtype' => 'due',
+                'timestart' => $now + 86400,
+                'timeduration' => 0,
+                'visible' => 1,
+                'priority' => CALENDAR_EVENT_USER_OVERRIDE_PRIORITY
+            ], [
+                'name' => 'Assignment 1 due date - Group A override',
+                'description' => '',
+                'format' => 1,
+                'courseid' => $course->id,
+                'groupid' => $group1->id,
+                'userid' => 2,
+                'modulename' => 'assign',
+                'instance' => $instance->id,
+                'eventtype' => 'due',
+                'timestart' => $now + (2 * 86400),
+                'timeduration' => 0,
+                'visible' => 1,
+                'priority' => 1,
+            ], [
+                'name' => 'Assignment 1 due date - Group B override',
+                'description' => '',
+                'format' => 1,
+                'courseid' => $course->id,
+                'groupid' => $group2->id,
+                'userid' => 2,
+                'modulename' => 'assign',
+                'instance' => $instance->id,
+                'eventtype' => 'due',
+                'timestart' => $now + (3 * 86400),
+                'timeduration' => 0,
+                'visible' => 1,
+                'priority' => 2,
+            ],
+        ];
+
+        foreach ($events as $event) {
+            calendar_event::create($event, false);
+        }
+
+        $timestart = $now - 100;
+        $timeend = $now + (3 * 86400);
+
+        $groups = [$group1->id, $group2->id];
+
+        // Get user override events.
+        $this->setUser($useroverridestudent);
+        $events = calendar_get_events($timestart, $timeend, $useroverridestudent->id, $groups, $course->id);
+        $this->assertCount(1, $events);
+        $event = reset($events);
+        $this->assertEquals('Assignment 1 due date - User override', $event->name);
+
+        // Get event for user with override but with the timestart and timeend parameters only covering the original event.
+        $events = calendar_get_events($timestart, $now, $useroverridestudent->id, $groups, $course->id);
+        $this->assertCount(0, $events);
+
+        // Get events for user that does not belong to any group and has no user override events.
+        $this->setUser($nogroupstudent);
+        $events = calendar_get_events($timestart, $timeend, $nogroupstudent->id, $groups, $course->id);
+        $this->assertCount(1, $events);
+        $event = reset($events);
+        $this->assertEquals('Assignment 1 due date', $event->name);
+
+        // Get events for user that belongs to groups A and B and has no user override events.
+        $this->setUser($group12student);
+        $events = calendar_get_events($timestart, $timeend, $group12student->id, $groups, $course->id);
+        $this->assertCount(1, $events);
+        $event = reset($events);
+        $this->assertEquals('Assignment 1 due date - Group B override', $event->name);
+
+        // Get events for user that belongs to group A and has no user override events.
+        $this->setUser($group1student);
+        $events = calendar_get_events($timestart, $timeend, $group1student->id, $groups, $course->id);
+        $this->assertCount(1, $events);
+        $event = reset($events);
+        $this->assertEquals('Assignment 1 due date - Group A override', $event->name);
+
+        // Add repeating events.
+        $repeatingevents = [
+            [
+                'name' => 'Repeating site event',
+                'description' => '',
+                'format' => 1,
+                'courseid' => SITEID,
+                'groupid' => 0,
+                'userid' => 2,
+                'repeatid' => 1,
+                'modulename' => '0',
+                'instance' => 0,
+                'eventtype' => 'site',
+                'timestart' => $now + 86400,
+                'timeduration' => 0,
+                'visible' => 1,
+            ],
+            [
+                'name' => 'Repeating site event',
+                'description' => '',
+                'format' => 1,
+                'courseid' => SITEID,
+                'groupid' => 0,
+                'userid' => 2,
+                'repeatid' => 1,
+                'modulename' => '0',
+                'instance' => 0,
+                'eventtype' => 'site',
+                'timestart' => $now + (2 * 86400),
+                'timeduration' => 0,
+                'visible' => 1,
+            ],
+        ];
+        foreach ($repeatingevents as $event) {
+            calendar_event::create($event, false);
+        }
+
+        // Make sure repeating events are not filtered out.
+        $events = calendar_get_events($timestart, $timeend, true, true, true);
+        $this->assertCount(3, $events);
+    }
 }

lib/classes/task/refresh_mod_calendar_events_task.php

@@ -0,0 +1,69 @@
+<?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/>.
+
+/**
+ * Adhoc task that updates all of the existing calendar events for modules that implement the *_refresh_events() hook.
+ *
+ * @package    core
+ * @copyright  2017 Jun Pataleta
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+namespace core\task;
+
+use core_plugin_manager;
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * Class that updates all of the existing calendar events for modules that implement the *_refresh_events() hook.
+ *
+ * Custom data accepted:
+ * - plugins -> Array of plugin names that need to be refreshed. Optional.
+ *
+ * @package     core
+ * @copyright   2017 Jun Pataleta
+ * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class refresh_mod_calendar_events_task extends adhoc_task {
+
+    /**
+     * Run the task to refresh calendar events.
+     */
+    public function execute() {
+        // Specific list of plugins that need to be refreshed. If not set, then all mod plugins will be refreshed.
+        $pluginstorefresh = null;
+        if (isset($this->get_custom_data()->plugins)) {
+            $pluginstorefresh = $this->get_custom_data()->plugins;
+        }
+
+        $pluginmanager = core_plugin_manager::instance();
+        $modplugins = $pluginmanager->get_plugins_of_type('mod');
+        foreach ($modplugins as $plugin) {
+            // Check if a specific list of plugins is defined and check if it contains the plugin that is currently being evaluated.
+            if (!empty($pluginstorefresh) && !in_array($plugin->name, $pluginstorefresh)) {
+                // This plugin is not in the list, move on to the next one.
+                continue;
+            }
+            // Check if the plugin implements *_refresh_events() and call it when it does.
+            $refresheventsfunction = $plugin->name . '_refresh_events';
+            if (function_exists($refresheventsfunction)) {
+                mtrace('Calling ' . $refresheventsfunction);
+                call_user_func($refresheventsfunction);
+            }
+        }
+    }
+}

lib/db/install.xml

@@ -439,6 +439,7 @@
         <FIELD NAME="sequence" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="1" SEQUENCE="false"/>
         <FIELD NAME="timemodified" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false"/>
         <FIELD NAME="subscriptionid" TYPE="int" LENGTH="10" NOTNULL="false" SEQUENCE="false" COMMENT="The event_subscription id this event is associated with."/>
+        <FIELD NAME="priority" TYPE="int" LENGTH="10" NOTNULL="false" SEQUENCE="false" COMMENT="The event's display priority. For multiple events with the same module name, instance and eventtype (e.g. for group overrides), the one with the higher priority will be displayed."/>
       </FIELDS>
       <KEYS>
         <KEY NAME="primary" TYPE="primary" FIELDS="id"/>

lib/db/upgrade.php

@@ -2555,5 +2555,29 @@ function xmldb_main_upgrade($oldversion) {
         upgrade_main_savepoint(true, 2017021400.00);
     }
 
+    if ($oldversion < 2017030700.00) {
+
+        // Define field priority to be added to event.
+        $table = new xmldb_table('event');
+        $field = new xmldb_field('priority', XMLDB_TYPE_INTEGER, '10', null, null, null, null, 'subscriptionid');
+
+        // Conditionally launch add field priority.
+        if (!$dbman->field_exists($table, $field)) {
+            $dbman->add_field($table, $field);
+        }
+
+        // Create adhoc task for upgrading of existing calendar events.
+        $record = new \stdClass();
+        $record->classname = "\\core\\task\\refresh_mod_calendar_events_task";
+        $record->component = 'core';
+        // Next run time based from nextruntime computation in \core\task\manager::queue_adhoc_task().
+        $nextruntime = time() - 1;
+        $record->nextruntime = $nextruntime;
+        $DB->insert_record('task_adhoc', $record);
+
+        // Main savepoint reached.
+        upgrade_main_savepoint(true, 2017030700.00);
+    }
+
     return true;
 }

lib/upgrade.txt

@@ -53,6 +53,8 @@ information provided here is intended especially for developers.
 * get_user_capability_course() now has an additional parameter 'limit'. This can be used to return a set number of records with
   the submitted capability. The parameter 'fieldsexceptid' will now accept context fields which can be used for preloading.
 * The caching option 'immutable' has been added to send_stored_file() and send_file().
+* New adhoc task refresh_mod_calendar_events_task that updates existing calendar events of modules.
+* New 'priority' column for the event table to determine which event to show in case of events with user and group overrides.
 
 === 3.2 ===
 

mod/assign/db/upgrade.php

@@ -233,5 +233,25 @@ function xmldb_assign_upgrade($oldversion) {
     // Automatically generated Moodle v3.2.0 release upgrade line.
     // Put any upgrade step following this.
 
+    if ($oldversion < 2017021500) {
+        // Fix event types of assign events.
+        $params = [
+            'modulename' => 'assign',
+            'eventtype' => 'close'
+        ];
+        $select = "modulename = :modulename AND eventtype = :eventtype";
+        $DB->set_field_select('event', 'eventtype', 'due', $select, $params);
+
+        // Delete 'open' events.
+        $params = [
+            'modulename' => 'assign',
+            'eventtype' => 'open'
+        ];
+        $DB->delete_records('event', $params);
+
+        // Assign savepoint reached.
+        upgrade_mod_savepoint(true, 2017021500, 'assign');
+    }
+
     return true;
 }

mod/assign/lib.php

@@ -226,10 +226,9 @@ function assign_update_events($assign, $override = null) {
     }
     $oldevents = $DB->get_records('event', $conds);
 
-    // Now make a todo list of all that needs to be updated.
+    // Now make a to-do list of all that needs to be updated.
     if (empty($override)) {
-        // We are updating the primary settings for the assign, so we
+        // We are updating the primary settings for the assign, so we need to add all the overrides.
-        // need to add all the overrides.
         $overrides = $DB->get_records('assign_overrides', array('assignid' => $assign->id));
         // As well as the original assign (empty override).
         $overrides[] = new stdClass();
@@ -241,12 +240,9 @@ function assign_update_events($assign, $override = null) {
     foreach ($overrides as $current) {
         $groupid   = isset($current->groupid) ? $current->groupid : 0;
         $userid    = isset($current->userid) ? $current->userid : 0;
-        $allowsubmissionsfromdate  = isset($current->allowsubmissionsfromdate
-        ) ? $current->allowsubmissionsfromdate : $assign->get_context()->allowsubmissionsfromdate;
         $duedate = isset($current->duedate) ? $current->duedate : $assign->get_context()->duedate;
 
-        // Only add open/close events for an override if they differ from the assign default.
+        // Only add 'due' events for an override if they differ from the assign default.
-        $addopen  = empty($current->id) || !empty($current->allowsubmissionsfromdate);
         $addclose = empty($current->id) || !empty($current->duedate);
 
         if (!empty($assign->coursemodule)) {
@@ -263,13 +259,14 @@ function assign_update_events($assign, $override = null) {
         $event->userid      = $userid;
         $event->modulename  = 'assign';
         $event->instance    = $assign->get_context()->id;
-        $event->timestart   = $allowsubmissionsfromdate;
+        $event->timestart   = $duedate;
-        $event->timeduration = max($duedate - $allowsubmissionsfromdate, 0);
+        $event->timeduration = 0;
         $event->visible     = instance_is_visible('assign', $assign);
-        $event->eventtype   = 'open';
+        $event->eventtype   = 'due';
 
-        // Determine the event name.
+        // Determine the event name and priority.
         if ($groupid) {
+            // Group override event.
             $params = new stdClass();
             $params->assign = $assign->get_context()->name;
             $params->group = groups_get_group_name($groupid);
@@ -278,49 +275,32 @@ function assign_update_events($assign, $override = null) {
                 continue;
             }
             $eventname = get_string('overridegroupeventname', 'assign', $params);
+            // Set group override priority.
+            if (isset($current->sortorder)) {
+                $event->priority = $current->sortorder;
+            }
         } else if ($userid) {
+            // User override event.
             $params = new stdClass();
             $params->assign = $assign->get_context()->name;
             $eventname = get_string('overrideusereventname', 'assign', $params);
+            // Set user override priority.
+            $event->priority = CALENDAR_EVENT_USER_OVERRIDE_PRIORITY;
         } else {
+            // The parent event.
             $eventname = $assign->name;
         }
-        if ($addopen or $addclose) {
+
-            if ($duedate and $allowsubmissionsfromdate and $event->timeduration <= ASSIGN_MAX_EVENT_LENGTH) {
+        if ($duedate && $addclose) {
-                // Single event for the whole assign.
+            if ($oldevent = array_shift($oldevents)) {
-                if ($oldevent = array_shift($oldevents)) {
+                $event->id = $oldevent->id;
-                    $event->id = $oldevent->id;
-                } else {
-                    unset($event->id);
-                }
-                $event->name = $eventname;
-                // The method calendar_event::create will reuse a db record if the id field is set.
-                calendar_event::create($event);
             } else {
-                // Separate start and end events.
+                unset($event->id);
-                $event->timeduration  = 0;
-                if ($allowsubmissionsfromdate && $addopen) {
-                    if ($oldevent = array_shift($oldevents)) {
-                        $event->id = $oldevent->id;
-                    } else {
-                        unset($event->id);
-                    }
-                    $event->name = $eventname.' ('.get_string('open', 'assign').')';
-                    // The method calendar_event::create will reuse a db record if the id field is set.
-                    calendar_event::create($event);
-                }
-                if ($duedate && $addclose) {
-                    if ($oldevent = array_shift($oldevents)) {
-                        $event->id = $oldevent->id;
-                    } else {
-                        unset($event->id);
-                    }
-                    $event->name      = $eventname.' ('.get_string('duedate', 'assign').')';
-                    $event->timestart = $duedate;
-                    $event->eventtype = 'close';
-                    calendar_event::create($event);
-                }
             }
+            $event->name      = $eventname.' ('.get_string('duedate', 'assign').')';
+            $event->timestart = $duedate;
+            $event->eventtype = 'due';
+            calendar_event::create($event);
         }
     }
 

mod/assign/locallib.php

@@ -1160,8 +1160,14 @@ class assign {
         if ($instance->duedate) {
             $event = new stdClass();
 
+            // Fetch the original due date event. It will have a non-zero course ID and a zero group ID.
+            $select = "modulename = :modulename
+                       AND instance = :instance
+                       AND eventtype = :eventtype
+                       AND groupid = 0
+                       AND courseid <> 0";
             $params = array('modulename' => 'assign', 'instance' => $instance->id, 'eventtype' => $eventtype);
-            $event->id = $DB->get_field('event', 'id', $params);
+            $event->id = $DB->get_field_select('event', 'id', $select, $params);
             $event->name = $instance->name;
             $event->timestart = $instance->duedate;
 
@@ -8822,6 +8828,14 @@ function reorder_group_overrides($assignid) {
             $f->id = $override->id;
             $f->sortorder = $i++;
             $DB->update_record('assign_overrides', $f);
+
+            // Update priorities of group overrides.
+            $params = [
+                'modulename' => 'assign',
+                'instance' => $override->assignid,
+                'groupid' => $override->groupid
+            ];
+            $DB->set_field('event', 'priority', $f->sortorder, $params);
         }
     }
 }

mod/assign/upgrade.txt

@@ -1,5 +1,10 @@
 This files describes API changes in the assign code.
 
+=== 3.3 ===
+* Fixed calendar event types for overridden due dates from 'close' to 'due'.
+* Removed calendar event type of 'open', since mod_assign only has the 'due' event type. No point in creating an override event
+for an event type that does not exist.
+
 === 3.2 ===
 * External function mod_assign_external::get_assignments now returns additional optional fields:
    - preventsubmissionnotingroup: Prevent submission not in group.

mod/assign/version.php

@@ -25,6 +25,6 @@
 defined('MOODLE_INTERNAL') || die();
 
 $plugin->component = 'mod_assign'; // Full name of the plugin (used for diagnostics).
-$plugin->version  = 2016120500;    // The current module version (Date: YYYYMMDDXX).
+$plugin->version  = 2017021500;    // The current module version (Date: YYYYMMDDXX).
 $plugin->requires = 2016112900;    // Requires this Moodle version.
 $plugin->cron     = 60;

mod/lesson/lib.php

@@ -123,10 +123,9 @@ function lesson_update_events($lesson, $override = null) {
     }
     $oldevents = $DB->get_records('event', $conds);
 
-    // Now make a todo list of all that needs to be updated.
+    // Now make a to-do list of all that needs to be updated.
     if (empty($override)) {
-        // We are updating the primary settings for the lesson, so we
+        // We are updating the primary settings for the lesson, so we need to add all the overrides.
-        // need to add all the overrides.
         $overrides = $DB->get_records('lesson_overrides', array('lessonid' => $lesson->id));
         // As well as the original lesson (empty override).
         $overrides[] = new stdClass();
@@ -135,6 +134,9 @@ function lesson_update_events($lesson, $override = null) {
         $overrides = array($override);
     }
 
+    // Get group override priorities.
+    $grouppriorities = lesson_get_group_override_priorities($lesson->id);
+
     foreach ($overrides as $current) {
         $groupid   = isset($current->groupid) ? $current->groupid : 0;
         $userid    = isset($current->userid) ? $current->userid : 0;
@@ -164,8 +166,9 @@ function lesson_update_events($lesson, $override = null) {
         $event->visible     = instance_is_visible('lesson', $lesson);
         $event->eventtype   = 'open';
 
-        // Determine the event name.
+        // Determine the event name and priority.
         if ($groupid) {
+            // Group override event.
             $params = new stdClass();
             $params->lesson = $lesson->name;
             $params->group = groups_get_group_name($groupid);
@@ -174,48 +177,54 @@ function lesson_update_events($lesson, $override = null) {
                 continue;
             }
             $eventname = get_string('overridegroupeventname', 'lesson', $params);
+            // Set group override priority.
+            if ($grouppriorities !== null) {
+                $openpriorities = $grouppriorities['open'];
+                if (isset($openpriorities[$available])) {
+                    $event->priority = $openpriorities[$available];
+                }
+            }
         } else if ($userid) {
+            // User override event.
             $params = new stdClass();
             $params->lesson = $lesson->name;
             $eventname = get_string('overrideusereventname', 'lesson', $params);
+            // Set user override priority.
+            $event->priority = CALENDAR_EVENT_USER_OVERRIDE_PRIORITY;
         } else {
+            // The parent event.
             $eventname = $lesson->name;
         }
+
         if ($addopen or $addclose) {
-            if ($deadline and $available and $event->timeduration <= LESSON_MAX_EVENT_LENGTH) {
+            // Separate start and end events.
-                // Single event for the whole lesson.
+            $event->timeduration  = 0;
+            if ($available && $addopen) {
                 if ($oldevent = array_shift($oldevents)) {
                     $event->id = $oldevent->id;
                 } else {
                     unset($event->id);
                 }
-                $event->name = $eventname;
+                $event->name = $eventname.' ('.get_string('lessonopens', 'lesson').')';
                 // The method calendar_event::create will reuse a db record if the id field is set.
                 calendar_event::create($event);
-            } else {
+            }
-                // Separate start and end events.
+            if ($deadline && $addclose) {
-                $event->timeduration  = 0;
+                if ($oldevent = array_shift($oldevents)) {
-                if ($available && $addopen) {
+                    $event->id = $oldevent->id;
-                    if ($oldevent = array_shift($oldevents)) {
+                } else {
-                        $event->id = $oldevent->id;
+                    unset($event->id);
-                    } else {
-                        unset($event->id);
-                    }
-                    $event->name = $eventname.' ('.get_string('lessonopens', 'lesson').')';
-                    // The method calendar_event::create will reuse a db record if the id field is set.
-                    calendar_event::create($event);
                 }
-                if ($deadline && $addclose) {
+                $event->name      = $eventname.' ('.get_string('lessoncloses', 'lesson').')';
-                    if ($oldevent = array_shift($oldevents)) {
+                $event->timestart = $deadline;
-                        $event->id = $oldevent->id;
+                $event->eventtype = 'close';
-                    } else {
+                if ($groupid && $grouppriorities !== null) {
-                        unset($event->id);
+                    $closepriorities = $grouppriorities['close'];
+                    if (isset($closepriorities[$deadline])) {
+                        $event->priority = $closepriorities[$deadline];
                     }
-                    $event->name      = $eventname.' ('.get_string('lessoncloses', 'lesson').')';
-                    $event->timestart = $deadline;
-                    $event->eventtype = 'close';
-                    calendar_event::create($event);
                 }
+                calendar_event::create($event);
             }
         }
     }
@@ -227,6 +236,58 @@ function lesson_update_events($lesson, $override = null) {
     }
 }
 
+/**
+ * Calculates the priorities of timeopen and timeclose values for group overrides for a lesson.
+ *
+ * @param int $lessonid The quiz ID.
+ * @return array|null Array of group override priorities for open and close times. Null if there are no group overrides.
+ */
+function lesson_get_group_override_priorities($lessonid) {
+    global $DB;
+
+    // Fetch group overrides.
+    $where = 'lessonid = :lessonid AND groupid IS NOT NULL';
+    $params = ['lessonid' => $lessonid];
+    $overrides = $DB->get_records_select('lesson_overrides', $where, $params, '', 'id, groupid, available, deadline');
+    if (!$overrides) {
+        return null;
+    }
+
+    $grouptimeopen = [];
+    $grouptimeclose = [];
+    foreach ($overrides as $override) {
+        if ($override->available !== null && !in_array($override->available, $grouptimeopen)) {
+            $grouptimeopen[] = $override->available;
+        }
+        if ($override->deadline !== null && !in_array($override->deadline, $grouptimeclose)) {
+            $grouptimeclose[] = $override->deadline;
+        }
+    }
+
+    // Sort open times in descending manner. The earlier open time gets higher priority.
+    rsort($grouptimeopen);
+    // Set priorities.
+    $opengrouppriorities = [];
+    $openpriority = 1;
+    foreach ($grouptimeopen as $timeopen) {
+        $opengrouppriorities[$timeopen] = $openpriority++;
+    }
+
+    // Sort close times in ascending manner. The later close time gets higher priority.
+    sort($grouptimeclose);
+    // Set priorities.
+    $closegrouppriorities = [];
+    $closepriority = 1;
+    foreach ($grouptimeclose as $timeclose) {
+        $closegrouppriorities[$timeclose] = $closepriority++;
+    }
+
+    return [
+        'open' => $opengrouppriorities,
+        'close' => $closegrouppriorities
+    ];
+}
+
 /**
  * This standard function will check all instances of this module
  * and make sure there are up-to-date events created for each of them.

mod/lesson/overrideedit.php

@@ -196,7 +196,14 @@ if ($mform->is_cancelled()) {
         $event->trigger();
     }
 
-    lesson_update_events($lesson, $fromform);
+    if ($groupmode) {
+        // Priorities may have shifted, so we need to update all of the calendar events for group overrides.
+        lesson_update_events($lesson);
+    } else {
+        // User override. We only need to update the calendar event for this user override.
+        lesson_update_events($lesson, $fromform);
+    }
+
 
     if (!empty($fromform->submitbutton)) {
         redirect($overridelisturl);

mod/lesson/tests/lib_test.php

@@ -0,0 +1,85 @@
+<?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/>.
+
+/**
+ * Unit tests for mod/lesson/lib.php.
+ *
+ * @package    mod_lesson
+ * @category   test
+ * @copyright  2017 Jun Pataleta
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU Public License
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+global $CFG;
+require_once($CFG->dirroot . '/mod/lesson/lib.php');
+
+/**
+ * Unit tests for mod/lesson/lib.php.
+ *
+ * @copyright  2017 Jun Pataleta
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU Public License
+ */
+class mod_lesson_lib_testcase extends advanced_testcase {
+    /**
+     * Test for lesson_get_group_override_priorities().
+     */
+    public function test_lesson_get_group_override_priorities() {
+        global $DB;
+        $this->resetAfterTest();
+        $this->setAdminUser();
+
+        $dg = $this->getDataGenerator();
+        $course = $dg->create_course();
+        $lessonmodule = $this->getDataGenerator()->create_module('lesson', array('course' => $course->id));
+
+        $this->assertNull(lesson_get_group_override_priorities($lessonmodule->id));
+
+        $group1 = $this->getDataGenerator()->create_group(array('courseid' => $course->id));
+        $group2 = $this->getDataGenerator()->create_group(array('courseid' => $course->id));
+
+        $now = 100;
+        $override1 = (object)[
+            'lessonid' => $lessonmodule->id,
+            'groupid' => $group1->id,
+            'available' => $now,
+            'deadline' => $now + 20
+        ];
+        $DB->insert_record('lesson_overrides', $override1);
+
+        $override2 = (object)[
+            'lessonid' => $lessonmodule->id,
+            'groupid' => $group2->id,
+            'available' => $now - 10,
+            'deadline' => $now + 10
+        ];
+        $DB->insert_record('lesson_overrides', $override2);
+
+        $priorities = lesson_get_group_override_priorities($lessonmodule->id);
+        $this->assertNotEmpty($priorities);
+
+        $openpriorities = $priorities['open'];
+        // Override 2's time open has higher priority since it is sooner than override 1's.
+        $this->assertEquals(1, $openpriorities[$override1->available]);
+        $this->assertEquals(2, $openpriorities[$override2->available]);
+
+        $closepriorities = $priorities['close'];
+        // Override 1's time close has higher priority since it is later than override 2's.
+        $this->assertEquals(2, $closepriorities[$override1->deadline]);
+        $this->assertEquals(1, $closepriorities[$override2->deadline]);
+    }
+}

mod/quiz/lib.php

@@ -1202,10 +1202,9 @@ function quiz_update_events($quiz, $override = null) {
     }
     $oldevents = $DB->get_records('event', $conds);
 
-    // Now make a todo list of all that needs to be updated.
+    // Now make a to-do list of all that needs to be updated.
     if (empty($override)) {
-        // We are updating the primary settings for the quiz, so we
+        // We are updating the primary settings for the lesson, so we need to add all the overrides.
-        // need to add all the overrides.
         $overrides = $DB->get_records('quiz_overrides', array('quiz' => $quiz->id));
         // As well as the original quiz (empty override).
         $overrides[] = new stdClass();
@@ -1214,6 +1213,9 @@ function quiz_update_events($quiz, $override = null) {
         $overrides = array($override);
     }
 
+    // Get group override priorities.
+    $grouppriorities = quiz_get_group_override_priorities($quiz->id);
+
     foreach ($overrides as $current) {
         $groupid   = isset($current->groupid)?  $current->groupid : 0;
         $userid    = isset($current->userid)? $current->userid : 0;
@@ -1243,8 +1245,9 @@ function quiz_update_events($quiz, $override = null) {
         $event->visible     = instance_is_visible('quiz', $quiz);
         $event->eventtype   = 'open';
 
-        // Determine the event name.
+        // Determine the event name and priority.
         if ($groupid) {
+            // Group override event.
             $params = new stdClass();
             $params->quiz = $quiz->name;
             $params->group = groups_get_group_name($groupid);
@@ -1253,48 +1256,54 @@ function quiz_update_events($quiz, $override = null) {
                 continue;
             }
             $eventname = get_string('overridegroupeventname', 'quiz', $params);
+            // Set group override priority.
+            if ($grouppriorities !== null) {
+                $openpriorities = $grouppriorities['open'];
+                if (isset($openpriorities[$timeopen])) {
+                    $event->priority = $openpriorities[$timeopen];
+                }
+            }
         } else if ($userid) {
+            // User override event.
             $params = new stdClass();
             $params->quiz = $quiz->name;
             $eventname = get_string('overrideusereventname', 'quiz', $params);
+            // Set user override priority.
+            $event->priority = CALENDAR_EVENT_USER_OVERRIDE_PRIORITY;
         } else {
+            // The parent event.
             $eventname = $quiz->name;
         }
+
         if ($addopen or $addclose) {
-            if ($timeclose and $timeopen and $event->timeduration <= QUIZ_MAX_EVENT_LENGTH) {
+            // Separate start and end events.
-                // Single event for the whole quiz.
+            $event->timeduration  = 0;
+            if ($timeopen && $addopen) {
                 if ($oldevent = array_shift($oldevents)) {
                     $event->id = $oldevent->id;
                 } else {
                     unset($event->id);
                 }
-                $event->name = $eventname;
+                $event->name = $eventname.' ('.get_string('quizopens', 'quiz').')';
                 // The method calendar_event::create will reuse a db record if the id field is set.
                 calendar_event::create($event);
-            } else {
+            }
-                // Separate start and end events.
+            if ($timeclose && $addclose) {
-                $event->timeduration  = 0;
+                if ($oldevent = array_shift($oldevents)) {
-                if ($timeopen && $addopen) {
+                    $event->id = $oldevent->id;
-                    if ($oldevent = array_shift($oldevents)) {
+                } else {
-                        $event->id = $oldevent->id;
+                    unset($event->id);
-                    } else {
-                        unset($event->id);
-                    }
-                    $event->name = $eventname.' ('.get_string('quizopens', 'quiz').')';
-                    // The method calendar_event::create will reuse a db record if the id field is set.
-                    calendar_event::create($event);
                 }
-                if ($timeclose && $addclose) {
+                $event->name      = $eventname.' ('.get_string('quizcloses', 'quiz').')';
-                    if ($oldevent = array_shift($oldevents)) {
+                $event->timestart = $timeclose;
-                        $event->id = $oldevent->id;
+                $event->eventtype = 'close';
-                    } else {
+                if ($groupid && $grouppriorities !== null) {
-                        unset($event->id);
+                    $closepriorities = $grouppriorities['close'];
+                    if (isset($closepriorities[$timeclose])) {
+                        $event->priority = $closepriorities[$timeclose];
                     }
-                    $event->name      = $eventname.' ('.get_string('quizcloses', 'quiz').')';
-                    $event->timestart = $timeclose;
-                    $event->eventtype = 'close';
-                    calendar_event::create($event);
                 }
+                calendar_event::create($event);
             }
         }
     }
@@ -1306,6 +1315,58 @@ function quiz_update_events($quiz, $override = null) {
     }
 }
 
+/**
+ * Calculates the priorities of timeopen and timeclose values for group overrides for a quiz.
+ *
+ * @param int $quizid The quiz ID.
+ * @return array|null Array of group override priorities for open and close times. Null if there are no group overrides.
+ */
+function quiz_get_group_override_priorities($quizid) {
+    global $DB;
+
+    // Fetch group overrides.
+    $where = 'quiz = :quiz AND groupid IS NOT NULL';
+    $params = ['quiz' => $quizid];
+    $overrides = $DB->get_records_select('quiz_overrides', $where, $params, '', 'id, timeopen, timeclose');
+    if (!$overrides) {
+        return null;
+    }
+
+    $grouptimeopen = [];
+    $grouptimeclose = [];
+    foreach ($overrides as $override) {
+        if ($override->timeopen !== null && !in_array($override->timeopen, $grouptimeopen)) {
+            $grouptimeopen[] = $override->timeopen;
+        }
+        if ($override->timeclose !== null && !in_array($override->timeclose, $grouptimeclose)) {
+            $grouptimeclose[] = $override->timeclose;
+        }
+    }
+
+    // Sort open times in descending manner. The earlier open time gets higher priority.
+    rsort($grouptimeopen);
+    // Set priorities.
+    $opengrouppriorities = [];
+    $openpriority = 1;
+    foreach ($grouptimeopen as $timeopen) {
+        $opengrouppriorities[$timeopen] = $openpriority++;
+    }
+
+    // Sort close times in ascending manner. The later close time gets higher priority.
+    sort($grouptimeclose);
+    // Set priorities.
+    $closegrouppriorities = [];
+    $closepriority = 1;
+    foreach ($grouptimeclose as $timeclose) {
+        $closegrouppriorities[$timeclose] = $closepriority++;
+    }
+
+    return [
+        'open' => $opengrouppriorities,
+        'close' => $closegrouppriorities
+    ];
+}
+
 /**
  * List the actions that correspond to a view of this module.
  * This is used by the participation report.

mod/quiz/overrideedit.php

@@ -198,7 +198,13 @@ if ($mform->is_cancelled()) {
     }
 
     quiz_update_open_attempts(array('quizid'=>$quiz->id));
-    quiz_update_events($quiz, $fromform);
+    if ($groupmode) {
+        // Priorities may have shifted, so we need to update all of the calendar events for group overrides.
+        quiz_update_events($quiz);
+    } else {
+        // User override. We only need to update the calendar event for this user override.
+        quiz_update_events($quiz, $fromform);
+    }
 
     if (!empty($fromform->submitbutton)) {
         redirect($overridelisturl);

mod/quiz/tests/lib_test.php

@@ -449,4 +449,52 @@ class mod_quiz_lib_testcase extends advanced_testcase {
         $this->assertEquals($quiz2->id, $attempt->quiz);
     }
 
+    /**
+     * Test for quiz_get_group_override_priorities().
+     */
+    public function test_quiz_get_group_override_priorities() {
+        global $DB;
+        $this->resetAfterTest();
+
+        $dg = $this->getDataGenerator();
+        $quizgen = $dg->get_plugin_generator('mod_quiz');
+        $course = $dg->create_course();
+
+        $quiz = $quizgen->create_instance(['course' => $course->id, 'sumgrades' => 2]);
+
+        $this->assertNull(quiz_get_group_override_priorities($quiz->id));
+
+        $group1 = $this->getDataGenerator()->create_group(array('courseid' => $course->id));
+        $group2 = $this->getDataGenerator()->create_group(array('courseid' => $course->id));
+
+        $now = 100;
+        $override1 = (object)[
+            'quiz' => $quiz->id,
+            'groupid' => $group1->id,
+            'timeopen' => $now,
+            'timeclose' => $now + 20
+        ];
+        $DB->insert_record('quiz_overrides', $override1);
+
+        $override2 = (object)[
+            'quiz' => $quiz->id,
+            'groupid' => $group2->id,
+            'timeopen' => $now - 10,
+            'timeclose' => $now + 10
+        ];
+        $DB->insert_record('quiz_overrides', $override2);
+
+        $priorities = quiz_get_group_override_priorities($quiz->id);
+        $this->assertNotEmpty($priorities);
+
+        $openpriorities = $priorities['open'];
+        // Override 2's time open has higher priority since it is sooner than override 1's.
+        $this->assertEquals(1, $openpriorities[$override1->timeopen]);
+        $this->assertEquals(2, $openpriorities[$override2->timeopen]);
+
+        $closepriorities = $priorities['close'];
+        // Override 1's time close has higher priority since it is later than override 2's.
+        $this->assertEquals(2, $closepriorities[$override1->timeclose]);
+        $this->assertEquals(1, $closepriorities[$override2->timeclose]);
+    }
 }

version.php

@@ -29,7 +29,7 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$version  = 2017030600.00;              // YYYYMMDD      = weekly release date of this DEV branch.
+$version  = 2017030700.00;              // YYYYMMDD      = weekly release date of this DEV branch.
                                         //         RR    = release increments - 00 in DEV branches.
                                         //           .XX = incremental changes.