Unique key for DataObject

src/ORM/DataObject.php

@@ -3236,9 +3236,10 @@ public static function get_one($callerClass = null, $filter = "", $cache = true,
         if ($callerClass === self::class) {
             throw new InvalidArgumentException('DataObject::get_one() cannot query non-subclass DataObject directly');
         }
-        $SNG = singleton($callerClass);
 
-        $cacheComponents = array($filter, $orderBy, $SNG->extend('cacheKeyComponent'));
+        /** @var DataObject $singleton */
+        $singleton = singleton($callerClass);
+        $cacheComponents = [$filter, $orderBy, $singleton->getCacheKeyComponent()];
         $cacheKey = md5(serialize($cacheComponents));
 
         $item = null;
@@ -4209,6 +4210,35 @@ public function mergeRelatedObjects($list, $items)
         return $added;
     }
 
+    /**
+     * Generate a unique key for data object
+     * the unique key uses the @see DataObject::getCacheKeyComponent() extension point so unique key modifiers
+     * such as versioned or fluent are covered
+     * i.e. same data object in different stages or different locales will produce different unique key
+     *
+     * recommended use:
+     * - when you need unique key for caching purposes
+     * - when you need unique id on the front end (for example JavaScript needs to target specific element)
+     *
+     * @return string
+     */
+    public function getUniqueKey(): string
+    {
+        // extract class name (remove namespaces)
+        $classSegments = explode('\\', $this->ClassName);
+
+        if (count($classSegments) === 0) {
+            return '';
+        }
+
+        $class = array_pop($classSegments);
+        $cacheKeys = $this->getCacheKeyComponent();
+        $cacheKeys = json_encode($cacheKeys);
+        $hash = md5(sprintf('%s-%s-%d', $cacheKeys, $this->ClassName, $this->ID));
+
+        return sprintf('ss-%s-%d-%s', $class, $this->ID, $hash);
+    }
+
     /**
      * Merge single object into a list, but ensures that existing objects are not
      * re-added.
@@ -4234,4 +4264,9 @@ protected function mergeRelatedObject($list, $added, $item)
             $this->mergeRelatedObject($list, $added, $joined);
         }
     }
+
+    protected function getCacheKeyComponent(): array
+    {
+        return $this->extend('cacheKeyComponent');
+    }
 }

tests/php/ORM/DataObjectTest.php

@@ -2536,4 +2536,26 @@ public function testShallowRecursiveWrite()
             'Root is 2 step remove from grand children. It was not written on a shallow recursive write.'
         );
     }
+
+    /**
+     * @param string $identifier
+     * @param string $class
+     * @param string $expected
+     * @dataProvider uniqueKeysProvider
+     */
+    public function testUniqueKey(string $identifier, string $class, string $expected): void
+    {
+        $object = $this->objFromFixture($class, $identifier);
+        $this->assertEquals($expected, $object->getUniqueKey());
+    }
+
+    public function uniqueKeysProvider(): array
+    {
+        return [
+            ['team1', DataObjectTest\Team::class, 'ss-Team-1-a4ec237d518051effd373f90dad9a1e2'],
+            ['team2', DataObjectTest\Team::class, 'ss-Team-2-69de0ff334cf4687a528c2dbbe198d7d'],
+            ['captain1', DataObjectTest\Player::class, 'ss-Player-1-8fdb4b4c871b413daa017f89e43aadd5'],
+            ['captain2', DataObjectTest\Player::class, 'ss-Player-2-096c7afa2396936b75e045a27b708f8b'],
+        ];
+    }
 }