From ab60a167e6ceeef2903db2eee09f31d35ed080e8 Mon Sep 17 00:00:00 2001
From: Andrew Aitken-Fincham <andrew@silverstripe.com>
Date: Wed, 21 Jun 2017 16:13:55 +0100
Subject: [PATCH] add inGroup(s) methods to Group

---
 src/Security/Group.php           | 58 ++++++++++++++++++++++++++++++++
 tests/php/Security/GroupTest.php | 31 +++++++++++++++++
 2 files changed, 89 insertions(+)

diff --git a/src/Security/Group.php b/src/Security/Group.php
index 4382366f5..ea61018d1 100755
--- a/src/Security/Group.php
+++ b/src/Security/Group.php
@@ -376,6 +376,64 @@ class Group extends DataObject
         return $items;
     }
 
+    /**
+     * Check if the group is a child of the given group or any parent groups
+     *
+     * @param string|int|Group $group Group instance, Group Code or ID
+     * @return bool Returns TRUE if the Group is a child of the given group, otherwise FALSE
+     */
+    public function inGroup($group)
+    {
+        return in_array($this->identifierToGroupID($group), $this->collateAncestorIDs());
+    }
+
+    /**
+     * Check if the group is a child of the given groups or any parent groups
+     *
+     * @param (string|int|Group)[] $groups
+     * @param bool $requireAll set to TRUE if must be in ALL groups, or FALSE if must be in ANY
+     * @return bool Returns TRUE if the Group is a child of any of the given groups, otherwise FALSE
+     */
+    public function inGroups($groups, $requireAll = false)
+    {
+        $ancestorIDs = $this->collateAncestorIDs();
+        $candidateIDs = [];
+        foreach ($groups as $group) {
+            $groupID = $this->identifierToGroupID($group);
+            if ($groupID) {
+                $candidateIDs[] = $groupID;
+            } elseif ($requireAll) {
+                return false;
+            }
+        }
+        if (empty($candidateIDs)) {
+            return false;
+        }
+        $matches = array_intersect($candidateIDs, $ancestorIDs);
+        if ($requireAll) {
+            return count($candidateIDs) === count($matches);
+        }
+        return !empty($matches);
+    }
+
+    /**
+     * Turn a string|int|Group into a GroupID
+     *
+     * @param string|int|Group $groupID Group instance, Group Code or ID
+     * @return int|null the Group ID or NULL if not found
+     */
+    protected function identifierToGroupID($groupID)
+    {
+        if (is_numeric($groupID) && Group::get()->byID($groupID)) {
+            return $groupID;
+        } elseif (is_string($groupID) && $groupByCode = Group::get()->filter(['Code' => $groupID])->first()) {
+            return $groupByCode->ID;
+        } elseif ($groupID instanceof Group && $groupID->exists()) {
+            return $groupID->ID;
+        }
+        return null;
+    }
+
     /**
      * This isn't a decendant of SiteTree, but needs this in case
      * the group is "reorganised";
diff --git a/tests/php/Security/GroupTest.php b/tests/php/Security/GroupTest.php
index 0b8e9f727..17068af8a 100644
--- a/tests/php/Security/GroupTest.php
+++ b/tests/php/Security/GroupTest.php
@@ -171,6 +171,37 @@ class GroupTest extends FunctionalTest
         $this->assertSame(['childgroup', 'grandchildgroup'], $children->column('Code'));
     }
 
+    public function testGroupInGroupMethods()
+    {
+        $parentGroup = $this->objFromFixture(Group::class, 'parentgroup');
+        $childGroup = $this->objFromFixture(Group::class, 'childgroup');
+        $grandchildGroup = $this->objFromFixture(Group::class, 'grandchildgroup');
+        $adminGroup = $this->objFromFixture(Group::class, 'admingroup');
+        $group1 = $this->objFromFixture(Group::class, 'group1');
+
+        $this->assertTrue($grandchildGroup->inGroup($childGroup));
+        $this->assertTrue($grandchildGroup->inGroup($childGroup->ID));
+        $this->assertTrue($grandchildGroup->inGroup($childGroup->Code));
+
+        $this->assertTrue($grandchildGroup->inGroup($parentGroup));
+        $this->assertTrue($grandchildGroup->inGroups([$parentGroup, $childGroup]));
+        $this->assertTrue($grandchildGroup->inGroups([$childGroup, $parentGroup]));
+        $this->assertTrue($grandchildGroup->inGroups([$parentGroup, $childGroup], true));
+
+        $this->assertFalse($grandchildGroup->inGroup($adminGroup));
+        $this->assertFalse($grandchildGroup->inGroups([$adminGroup, $group1]));
+        $this->assertFalse($grandchildGroup->inGroups([$adminGroup, $childGroup], true));
+
+        $this->assertFalse($grandchildGroup->inGroup('NotARealGroup'));
+        $this->assertFalse($grandchildGroup->inGroup(99999999999));
+        $this->assertFalse($grandchildGroup->inGroup(new TestMember()));
+
+        // Edgecases
+        $this->assertTrue($grandchildGroup->inGroup($grandchildGroup));
+        $this->assertFalse($grandchildGroup->inGroups([]));
+        $this->assertFalse($grandchildGroup->inGroups([], true));
+    }
+
     public function testDelete()
     {
         $group = $this->objFromFixture(Group::class, 'parentgroup');