diff --git a/src/Exceptions/InvalidDataException.php b/src/Exceptions/InvalidDataException.php
new file mode 100644
index 0000000..7ed3b11
--- /dev/null
+++ b/src/Exceptions/InvalidDataException.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace MiroClipboard\Exceptions;
+
+use Throwable;
+
+class InvalidDataException extends MiroDataException
+{
+    public function __construct(int $code = 0, ?Throwable $previous = null)
+    {
+        parent::__construct('Unable to parse miro clipboard data', $code, $previous);
+    }
+}
diff --git a/src/Exceptions/MiroDataException.php b/src/Exceptions/MiroDataException.php
new file mode 100644
index 0000000..202aafe
--- /dev/null
+++ b/src/Exceptions/MiroDataException.php
@@ -0,0 +1,7 @@
+<?php
+
+namespace MiroClipboard\Exceptions;
+
+class MiroDataException extends \Exception
+{
+}
diff --git a/src/Exceptions/ParserNotResolvedException.php b/src/Exceptions/ParserNotResolvedException.php
index 0276d8b..aa59359 100644
--- a/src/Exceptions/ParserNotResolvedException.php
+++ b/src/Exceptions/ParserNotResolvedException.php
@@ -4,7 +4,7 @@
 
 use Throwable;
 
-class ParserNotResolvedException extends \Exception
+class ParserNotResolvedException extends MiroDataException
 {
     public function __construct(string $parserType, int $code = 0, ?Throwable $previous = null)
     {
diff --git a/src/MiroParser.php b/src/MiroParser.php
index 65df4e9..74961c1 100644
--- a/src/MiroParser.php
+++ b/src/MiroParser.php
@@ -9,6 +9,7 @@
 use MiroClipboard\Parsers\LineParser;
 use MiroClipboard\Parsers\MiroParserInterface;
 use MiroClipboard\Parsers\ShapeParser;
+use MiroClipboard\Utility\HasGroup;
 
 use function MiroClipboard\MiroUtility\decodeMiroDataString;
 
@@ -40,6 +41,9 @@ public static function parse(string|array $data): MiroClipboardData
             if (method_exists($object, 'resolveClipboardDataReferences')) {
                 $object->resolveClipboardDataReferences($newClipboardData);
             }
+            if (in_array(HasGroup::class, class_uses($object))) {
+                $object->resolveGroupClipboardDataReferences($newClipboardData);
+            }
         }
 
         return $newClipboardData;
diff --git a/src/Objects/MiroGroup.php b/src/Objects/MiroGroup.php
index 612fc9c..7f0ef66 100644
--- a/src/Objects/MiroGroup.php
+++ b/src/Objects/MiroGroup.php
@@ -4,6 +4,7 @@
 
 use MiroClipboard\Enums\ObjectType;
 use MiroClipboard\MiroClipboardData;
+use MiroClipboard\Utility\HasGroup;
 use MiroClipboard\Utility\Makeable;
 
 class MiroGroup extends MiroObject
@@ -33,6 +34,10 @@ public function __construct()
     public function add(int|MiroObject $object): static
     {
         if ($object instanceof MiroObject) {
+            if (in_array(HasGroup::class, class_uses($object))) {
+                $object->setGroup($this);
+            }
+
             $this->objects[] = $object;
             $this->ids[]     = $object->id;
         } else {
@@ -50,6 +55,18 @@ public function getObjects(): array
         return $this->objects;
     }
 
+    public function findObject(int|MiroObject $object): false|MiroObject
+    {
+        $searchId = is_int($object) ? $object : $object->getId();
+        foreach ($this->objects as $existing) {
+            if ($existing->getId() === $searchId) {
+                return $existing;
+            }
+        }
+
+        return false;
+    }
+
     /**
      * @param MiroClipboardData $clipboardData
      *
diff --git a/src/Objects/MiroLine.php b/src/Objects/MiroLine.php
index 14c6c10..a057c1b 100644
--- a/src/Objects/MiroLine.php
+++ b/src/Objects/MiroLine.php
@@ -7,10 +7,12 @@
 use MiroClipboard\MiroClipboardData;
 use MiroClipboard\MiroWidget;
 use MiroClipboard\Styles\MiroLineStyle;
+use MiroClipboard\Utility\HasGroup;
 use MiroClipboard\Utility\SetPropertiesFromArray;
 
 class MiroLine extends MiroWidget
 {
+    use HasGroup;
     use SetPropertiesFromArray;
 
     private MiroLineStyle $lineStyle;
diff --git a/src/Objects/MiroShape.php b/src/Objects/MiroShape.php
index a6b389b..0e06143 100644
--- a/src/Objects/MiroShape.php
+++ b/src/Objects/MiroShape.php
@@ -6,10 +6,12 @@
 use MiroClipboard\Enums\WidgetType;
 use MiroClipboard\MiroWidget;
 use MiroClipboard\Styles\MiroShapeStyle;
+use MiroClipboard\Utility\HasGroup;
 use MiroClipboard\Utility\SetPropertiesFromArray;
 
 class MiroShape extends MiroWidget
 {
+    use HasGroup;
     use SetPropertiesFromArray;
 
     private MiroShapeStyle $shapeStyle;
diff --git a/src/Utility/HasGroup.php b/src/Utility/HasGroup.php
new file mode 100644
index 0000000..2b3b147
--- /dev/null
+++ b/src/Utility/HasGroup.php
@@ -0,0 +1,46 @@
+<?php
+
+namespace MiroClipboard\Utility;
+
+use MiroClipboard\MiroClipboardData;
+use MiroClipboard\Objects\MiroGroup;
+
+trait HasGroup
+{
+    protected ?MiroGroup $group = null;
+
+    public function group(): ?MiroGroup
+    {
+        return $this->group;
+    }
+
+    /**
+     * @internal
+     */
+    public function setGroup(MiroGroup $group): static
+    {
+        $this->group = $group;
+
+        return $this;
+    }
+
+    /**
+     * @param MiroClipboardData $clipboardData
+     *
+     * @return void
+     *
+     * @internal
+     */
+    public function resolveGroupClipboardDataReferences(MiroClipboardData $clipboardData): void
+    {
+        foreach ($clipboardData->getObjects() as $object) {
+            if ($object instanceof MiroGroup) {
+                if (in_array($this->getId(), $found = $object->toArray()['items'])) {
+                    if (in_array(HasGroup::class, class_uses(static::class))) {
+                        $this->group = $object;
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/src/Utility/MiroUtility.php b/src/Utility/MiroUtility.php
index 5285fcd..f88fb20 100644
--- a/src/Utility/MiroUtility.php
+++ b/src/Utility/MiroUtility.php
@@ -2,6 +2,8 @@
 
 namespace MiroClipboard\MiroUtility;
 
+use MiroClipboard\Exceptions\InvalidDataException;
+
 use function MiroClipboard\Utility\stringToByteArray;
 
 function encodeMiroData(array $data, int $encodingOffset = 59): string
@@ -21,9 +23,12 @@ function encodeMiroData(array $data, int $encodingOffset = 59): string
 
 function decodeMiroDataString(string $text, int $encodingOffset = 59): array
 {
-    $isHtml = preg_match('/(?:^.*?\(miro-data-v[0-9]+\))(.*?)(?:\(\/miro-data-v[0-9]+\).*?$)/', $text, $matches);
+    $isHtml = preg_match('/(?:^.*?\(miro-data-v[0-9]+\))(.*?)(?:\(\/miro-data-v[0-9]+\).*?$)/m', $text, $matches);
+
     if ($isHtml) {
         $text = $matches[1];
+    } else {
+        throw new InvalidDataException();
     }
 
     $text = base64_decode($text);
diff --git a/src/Utility/SetPropertiesFromArray.php b/src/Utility/SetPropertiesFromArray.php
index fa7edb4..4d6ef8b 100644
--- a/src/Utility/SetPropertiesFromArray.php
+++ b/src/Utility/SetPropertiesFromArray.php
@@ -32,6 +32,8 @@ enum_exists($enumName = $propType->getName()) &&
                 ) {
                     /** @phpstan-ignore-next-line */
                     $this->$key = $enumName::from($val);
+                } elseif ($propType->allowsNull() && empty($val)) {
+                    $this->$key = null;
                 } else {
                     $this->$key = $val;
                 }
diff --git a/tests/Unit/MiroGroupTest.php b/tests/Unit/MiroGroupTest.php
index e1d0dfc..b18ee5f 100644
--- a/tests/Unit/MiroGroupTest.php
+++ b/tests/Unit/MiroGroupTest.php
@@ -8,22 +8,35 @@
 test('create group from array', function() {
     $clipboardData = MiroClipboardData::make()
         ->addGroup([
-            MiroWidget::make()->shape()->text('hello')->position(100, 100),
-            MiroWidget::make()->shape()->text('world')->position(200, 200),
+            $shape1 = MiroWidget::make()->shape()->text('hello')->position(100, 100),
+            $shape2 = MiroWidget::make()->shape()->text('world')->position(200, 200),
         ]);
 
     expect($clipboardData->getObjects())->toHaveCount(3);
+
+    expect($shape1->group())->toEqual($clipboardData->getObjects()[2]);
+    expect($shape2->group())->toEqual($clipboardData->getObjects()[2]);
 });
 
 test('create group from object', function() {
     $group = MiroGroup::make()
-        ->add(MiroWidget::make()->shape()->text('test1')->position(100, 100))
-        ->add(MiroWidget::make()->shape()->text('test2')->position(200, 200));
+        ->add($shape1 = MiroWidget::make()->shape()->text('test1')->position(100, 100))
+        ->add($shape2 = MiroWidget::make()->shape()->text('test2')->position(200, 200));
 
     $clipboardData = MiroClipboardData::make()->addObject($group);
 
     expect($clipboardData->getObjects())->toHaveCount(3);
     expect(array_map(fn($x) => get_class($x), $clipboardData->getObjects()))->toBe([MiroShape::class, MiroShape::class, MiroGroup::class]);
+
+    expect($shape1->group())->toEqual($group);
+    expect($shape2->group())->toEqual($group);
+});
+
+test('can get group of object', function() {
+    $group = MiroGroup::make()
+        ->add($shape = MiroWidget::make()->shape()->text('test1')->position(100, 100));
+
+    expect($shape->group())->toEqual($group);
 });
 
 test('group to array', function() {
@@ -34,3 +47,13 @@
 
     expect($group->toArray()['items'])->toBe([123, 456, 987]);
 });
+
+test('find object in group', function() {
+    $group = MiroGroup::make();
+
+    expect($group->findObject(123))->toBeFalse();
+
+    $group->add(MiroWidget::make()->id(123)->shape()->text('test1')->position(100, 100));
+
+    expect($group->findObject(123))->toBeInstanceOf(MiroShape::class);
+});
diff --git a/tests/Unit/ParserTest.php b/tests/Unit/ParserTest.php
index 5f25b92..ab190fb 100644
--- a/tests/Unit/ParserTest.php
+++ b/tests/Unit/ParserTest.php
@@ -20,6 +20,7 @@
 use MiroClipboard\Parsers\ShapeParser;
 use MiroClipboard\Styles\MiroLineStyle;
 use MiroClipboard\Styles\MiroShapeStyle;
+use MiroClipboard\Utility\SetPropertiesFromArray;
 
 test('parse string', function() {
     $shape = MiroWidget::make()->shape()->position(1.1, 1.1);
@@ -142,6 +143,19 @@
     expect(invade($parsedData->getObjects()[2])->objects)->toHaveCount(2);
 });
 
+test('parsed objects part of a group have a group reference', function() {
+    $clipboardData = MiroClipboardData::make()
+        ->addGroup(MiroGroup::make()
+            ->add(MiroWidget::make()->shape()->text('hello')->position(100, 100))
+        );
+
+    $parsedData = MiroClipboardData::parse($clipboardData->toHTML());
+
+    expect($shape = $parsedData->getObjects()[0])->toBeInstanceOf(MiroShape::class);
+
+    expect($shape->group())->toEqual($parsedData->getObjects()[1]);
+});
+
 test('line object to and from objects are set', function() {
     $clipboardData = MiroClipboardData::make()
         ->addObject(MiroLine::make()->id(1)
@@ -159,3 +173,19 @@
     expect(invade($line)->fromObject)->toBeInstanceOf(MiroShape::class);
     expect(invade($line)->toObject)->toBeInstanceOf(MiroShape::class);
 });
+
+test('throws with invalid data', function() {
+    MiroParser::parse('test');
+})->throws(\MiroClipboard\Exceptions\InvalidDataException::class);
+
+test('parsing empty string into nullable field', function() {
+    $instance = new class()
+    {
+        public ?string $field;
+        use SetPropertiesFromArray;
+    };
+
+    $instance->setPropertiesFromArray(['field' => '']);
+
+    expect($instance->field)->toBeNull();
+});