[Form] Cast choices value callback result to string

Matth-- · nicolas-grekas · commit be580488c775 · 2023-04-17T16:07:13.000+02:00
If using "multiple" and "choice_value" on a CollectionType or EntityType, the result for the callback needs to be a string. By forcing a string cast, default values will show up in the form view.
diff --git a/src/Symfony/Component/Form/ChoiceList/Loader/AbstractChoiceLoader.php b/src/Symfony/Component/Form/ChoiceList/Loader/AbstractChoiceLoader.php
@@ -59,7 +59,7 @@ public function loadValuesForChoices(array $choices, callable $value = null)
 
         if ($value) {
             // if a value callback exists, use it
-            return array_map($value, $choices);
+            return array_map(function ($item) use ($value): string { return $value($item); }, $choices);
         }
 
         return $this->doLoadValuesForChoices($choices);
diff --git a/src/Symfony/Component/Form/Tests/ChoiceList/Loader/CallbackChoiceLoaderTest.php b/src/Symfony/Component/Form/Tests/ChoiceList/Loader/CallbackChoiceLoaderTest.php
@@ -90,6 +90,18 @@ public function testLoadChoicesForValuesLoadsChoiceListOnFirstCall()
         );
     }
 
+    public function testLoadValuesForChoicesCastsCallbackItemsToString()
+    {
+        $choices = [
+           (object) ['id' => 2],
+           (object) ['id' => 3],
+        ];
+
+        $value = function ($item) { return $item->id; };
+
+        $this->assertSame(['2', '3'], self::$loader->loadValuesForChoices($choices, $value));
+    }
+
     public function testLoadValuesForChoicesLoadsChoiceListOnFirstCall()
     {
         $this->assertSame(

Original file line number	Diff line number	Diff line change
`@@ -59,7 +59,7 @@ public function loadValuesForChoices(array $choices, callable $value = null)`
`59`	`59`
`60`	`60`	`if ($value) {`
`61`	`61`	`// if a value callback exists, use it`
`62`		`- return array_map($value, $choices);`
	`62`	`+ return array_map(function ($item) use ($value): string { return $value($item); }, $choices);`
`63`	`63`	`}`
`64`	`64`
`65`	`65`	`return $this->doLoadValuesForChoices($choices);`