From 404f450ac395143eee6bedd131b1c80f5742f8bd Mon Sep 17 00:00:00 2001
From: Martin Heise <info@martinheise.de>
Date: Thu, 16 Jul 2020 14:40:10 +0200
Subject: [PATCH] BUG Readonly version of GroupedDropdownField

GroupedDropdownField was showing empty values in Readonly mode due to not correctly handling the hierarchical source array.
Uses flattened source now in GroupedDropdownField->performReadonlyTransformation()
---
 src/Forms/GroupedDropdownField.php           | 11 ++++++
 tests/php/Forms/GroupedDropdownFieldTest.php | 35 ++++++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/src/Forms/GroupedDropdownField.php b/src/Forms/GroupedDropdownField.php
index 2dfd1e974..feb758361 100644
--- a/src/Forms/GroupedDropdownField.php
+++ b/src/Forms/GroupedDropdownField.php
@@ -2,6 +2,7 @@
 
 namespace SilverStripe\Forms;
 
+use SilverStripe\ORM\ArrayLib;
 use SilverStripe\ORM\ArrayList;
 use SilverStripe\View\ArrayData;
 
@@ -104,4 +105,14 @@ class GroupedDropdownField extends DropdownField
         );
         return $values;
     }
+
+    /**
+     * @return SingleLookupField
+     */
+    public function performReadonlyTransformation()
+    {
+        $field = parent::performReadonlyTransformation();
+        $field->setSource(ArrayLib::flatten($this->getSource()));
+        return $field;
+    }
 }
diff --git a/tests/php/Forms/GroupedDropdownFieldTest.php b/tests/php/Forms/GroupedDropdownFieldTest.php
index 47fb93fcc..fabb419b0 100644
--- a/tests/php/Forms/GroupedDropdownFieldTest.php
+++ b/tests/php/Forms/GroupedDropdownFieldTest.php
@@ -129,4 +129,39 @@ class GroupedDropdownFieldTest extends SapphireTest
             preg_replace('/\s+/', ' ', (string)$field->Field())
         );
     }
+
+    /**
+     * Test that readonly version of GroupedDropdownField displays all values
+     */
+    public function testReadonlyValue()
+    {
+        $field = GroupedDropdownField::create(
+            'Test',
+            'Testing',
+            [
+                "1" => "One",
+                "Group One" => [
+                    "2" => "Two",
+                    "3" => "Three"
+                ],
+                "Group Two" => [
+                    "4" => "Four"
+                ],
+            ]
+        );
+
+        // value on first level
+        $field->setValue("1");
+        $this->assertRegExp(
+            '/<span class="readonly" id="Test">One<\/span><input type="hidden" name="Test" value="1" \/>/',
+            (string)$field->performReadonlyTransformation()->Field()
+        );
+
+        // value on first level
+        $field->setValue("2");
+        $this->assertRegExp(
+            '/<span class="readonly" id="Test">Two<\/span><input type="hidden" name="Test" value="2" \/>/',
+            (string)$field->performReadonlyTransformation()->Field()
+        );
+    }
 }