From 158bc006a5b72ea64445caa8c77dab7dfd074b49 Mon Sep 17 00:00:00 2001
From: Guy Sartorelli <guy.sartorelli@silverstripe.com>
Date: Mon, 17 Apr 2023 13:45:22 +1200
Subject: [PATCH] FIX Format value to string for readonly transformation

Co-authored-by: Werner Huber <w.huber@byro13.de>
---
 src/StringTagField.php       |  7 +++++++
 tests/StringTagFieldTest.php | 34 +++++++++++++++++++---------------
 2 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/src/StringTagField.php b/src/StringTagField.php
index 556286f..57ebd61 100644
--- a/src/StringTagField.php
+++ b/src/StringTagField.php
@@ -412,4 +412,11 @@ public function setCanCreate($canCreate)
 
         return $this;
     }
+
+    public function performReadonlyTransformation()
+    {
+        $field = parent::performReadonlyTransformation();
+        $field->setValue(implode(', ', $this->Value()));
+        return $field;
+    }
 }
diff --git a/tests/StringTagFieldTest.php b/tests/StringTagFieldTest.php
index 024fd71..254041b 100755
--- a/tests/StringTagFieldTest.php
+++ b/tests/StringTagFieldTest.php
@@ -171,22 +171,26 @@ public function testSchemaIsAddedToAttributes()
         $this->assertNotEmpty($attributes['data-schema']);
     }
 
-    /**
-     * Ensure a source of tags matches the given string tag names
-     *
-     * @param array $expected
-     * @param DataList $actualSource
-     */
-    protected function compareTagLists(array $expected, DataList $actualSource)
+    public function testPerformReadonlyTransformation()
     {
-        $actual = array_keys($actualSource->map('ID', 'Title')->toArray());
-        sort($expected);
-        sort($actual);
-
-        $this->assertEquals(
-            $expected,
-            $actual
-        );
+        $field = new StringTagField('Tags');
+        $field->setSource(['Test1', 'Test2', 'Test3']);
+
+        // Ensure a single value can be rendered
+        $field->setValue(['Test2']);
+        $field_readonly = $field->performReadonlyTransformation();
+        $this->assertEquals('Test2', $field_readonly->Value());
+
+        // Ensure multiple valid values are rendered
+        $field->setValue(['Test1', 'Test2']);
+        $field_readonly = $field->performReadonlyTransformation();
+        $this->assertEquals('Test1, Test2', $field_readonly->Value());
+
+        // Ensure an value not in the source array is still rendered
+        // (because e.g. in history view it must have been a valid value when it was set)
+        $field->setValue(['Test', 'Test1']);
+        $field_readonly = $field->performReadonlyTransformation();
+        $this->assertEquals('Test, Test1', $field_readonly->Value());
     }
 
     /**