[LiveComponent] Fix data model radio checkbox

src/LiveComponent/src/EventListener/DataModelPropsSubscriber.php

@@ -64,8 +64,21 @@ public function onPreMount(PreMountEvent $event): void
         foreach ($bindings as $binding) {
             $childModel = $binding['child'];
             $parentModel = $binding['parent'];
+            $propValue = $this->propertyAccessor->getValue($parentMountedComponent->getComponent(), $parentModel);
 
-            $data[$childModel] = $this->propertyAccessor->getValue($parentMountedComponent->getComponent(), $parentModel);
+            if ('value' === $childModel && \array_key_exists('value', $data)) {
+                // Radio or checkbox group: an explicit option value was passed (e.g. value="a").
+                // Preserve it and derive the checked state from the parent prop instead.
+                $data['checked'] = \is_array($propValue)
+                    ? \in_array($data['value'], $propValue, false)
+                    : ($data['value'] == $propValue);
+            } elseif ('value' === $childModel && isset($data['type']) && 'checkbox' === $data['type']) {
+                // Boolean checkbox: type="checkbox" declared at call site but no explicit value.
+                // Set checked directly from the boolean prop; do not write a value attribute.
+                $data['checked'] = (bool) $propValue;
+            } else {
+                $data[$childModel] = $propValue;
+            }
         }
 
         $event->setData($data);

src/LiveComponent/tests/Fixtures/Component/CheckboxInputComponent.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace Symfony\UX\LiveComponent\Tests\Fixtures\Component;
+
+use Symfony\UX\TwigComponent\Attribute\AsTwigComponent;
+
+#[AsTwigComponent('checkbox_input')]
+final class CheckboxInputComponent
+{
+}

src/LiveComponent/tests/Fixtures/Component/ParentWithBoolCheckboxComponent.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Symfony\UX\LiveComponent\Tests\Fixtures\Component;
+
+use Symfony\UX\LiveComponent\Attribute\AsLiveComponent;
+use Symfony\UX\LiveComponent\Attribute\LiveProp;
+use Symfony\UX\LiveComponent\DefaultActionTrait;
+
+#[AsLiveComponent('parent_with_bool_checkbox')]
+final class ParentWithBoolCheckboxComponent
+{
+    use DefaultActionTrait;
+
+    #[LiveProp(writable: true)]
+    public bool $isActive = true;
+}

src/LiveComponent/tests/Fixtures/Component/ParentWithCheckboxGroupComponent.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Symfony\UX\LiveComponent\Tests\Fixtures\Component;
+
+use Symfony\UX\LiveComponent\Attribute\AsLiveComponent;
+use Symfony\UX\LiveComponent\Attribute\LiveProp;
+use Symfony\UX\LiveComponent\DefaultActionTrait;
+
+#[AsLiveComponent('parent_with_checkbox_group')]
+final class ParentWithCheckboxGroupComponent
+{
+    use DefaultActionTrait;
+
+    #[LiveProp(writable: true)]
+    public array $selected = ['a', 'c'];
+}

src/LiveComponent/tests/Fixtures/Component/ParentWithRadioGroupComponent.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Symfony\UX\LiveComponent\Tests\Fixtures\Component;
+
+use Symfony\UX\LiveComponent\Attribute\AsLiveComponent;
+use Symfony\UX\LiveComponent\Attribute\LiveProp;
+use Symfony\UX\LiveComponent\DefaultActionTrait;
+
+#[AsLiveComponent('parent_with_radio_group')]
+final class ParentWithRadioGroupComponent
+{
+    use DefaultActionTrait;
+
+    #[LiveProp(writable: true)]
+    public string $selected = 'b';
+}

src/LiveComponent/tests/Fixtures/Component/RadioInputComponent.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace Symfony\UX\LiveComponent\Tests\Fixtures\Component;
+
+use Symfony\UX\TwigComponent\Attribute\AsTwigComponent;
+
+#[AsTwigComponent('radio_input')]
+final class RadioInputComponent
+{
+}

src/LiveComponent/tests/Fixtures/templates/components/checkbox_input.html.twig

@@ -0,0 +1 @@
+<input{{ attributes }} />

src/LiveComponent/tests/Fixtures/templates/components/parent_with_bool_checkbox.html.twig

@@ -0,0 +1 @@
+{% component checkbox_input with { 'data-model': 'isActive', type: 'checkbox' } %}{% endcomponent %}

src/LiveComponent/tests/Fixtures/templates/components/parent_with_checkbox_group.html.twig

@@ -0,0 +1,3 @@
+{% component checkbox_input with { 'data-model': 'selected', value: 'a', type: 'checkbox' } %}{% endcomponent %}
+{% component checkbox_input with { 'data-model': 'selected', value: 'b', type: 'checkbox' } %}{% endcomponent %}
+{% component checkbox_input with { 'data-model': 'selected', value: 'c', type: 'checkbox' } %}{% endcomponent %}

src/LiveComponent/tests/Fixtures/templates/components/parent_with_radio_group.html.twig

@@ -0,0 +1,3 @@
+{% component radio_input with { 'data-model': 'selected', value: 'a', type: 'radio' } %}{% endcomponent %}
+{% component radio_input with { 'data-model': 'selected', value: 'b', type: 'radio' } %}{% endcomponent %}
+{% component radio_input with { 'data-model': 'selected', value: 'c', type: 'radio' } %}{% endcomponent %}

src/LiveComponent/tests/Fixtures/templates/components/radio_input.html.twig

@@ -0,0 +1 @@
+<input{{ attributes }} />

src/LiveComponent/tests/Integration/EventListener/DataModelPropsSubscriberTest.php

@@ -54,4 +54,66 @@ public function testDataModelPropsAreAvailableInEmbeddedComponents()
         $this->assertStringContainsString('<textarea data-model="content">default content on mount</textarea>', $html);
         $this->assertStringContainsString('<input data-model="content" value="default content on mount" />', $html);
     }
+
+    public function testRadioGroupPreservesValueAndSetsChecked()
+    {
+        /** @var ComponentRenderer $renderer */
+        $renderer = self::getContainer()->get('ux.twig_component.component_renderer');
+
+        $html = $renderer->createAndRender('parent_with_radio_group', [
+            'selected' => 'b',
+            'attributes' => ['id' => 'dummy-live-id'],
+        ]);
+
+        // value attributes must be preserved as-is
+        $this->assertStringContainsString('value="a"', $html);
+        $this->assertStringContainsString('value="b"', $html);
+        $this->assertStringContainsString('value="c"', $html);
+
+        // only the matching radio gets checked
+        $this->assertStringContainsString('value="b" type="radio" checked', $html);
+
+        // non-matching radios must not get checked
+        $this->assertStringNotContainsString('value="a" type="radio" checked', $html);
+        $this->assertStringNotContainsString('value="c" type="radio" checked', $html);
+    }
+
+    public function testCheckboxGroupPreservesValueAndSetsChecked()
+    {
+        /** @var ComponentRenderer $renderer */
+        $renderer = self::getContainer()->get('ux.twig_component.component_renderer');
+
+        $html = $renderer->createAndRender('parent_with_checkbox_group', [
+            'selected' => ['a', 'c'],
+            'attributes' => ['id' => 'dummy-live-id'],
+        ]);
+
+        // value attributes must be preserved as-is
+        $this->assertStringContainsString('value="a"', $html);
+        $this->assertStringContainsString('value="b"', $html);
+        $this->assertStringContainsString('value="c"', $html);
+
+        // selected checkboxes ('a' and 'c') get checked; unselected ('b') does not
+        $this->assertStringContainsString('value="a" type="checkbox" checked', $html);
+        $this->assertStringNotContainsString('value="b" type="checkbox" checked', $html);
+        $this->assertStringContainsString('value="c" type="checkbox" checked', $html);
+    }
+
+    public function testBooleanCheckboxSetsCheckedWithoutValueOverwrite()
+    {
+        /** @var ComponentRenderer $renderer */
+        $renderer = self::getContainer()->get('ux.twig_component.component_renderer');
+
+        $html = $renderer->createAndRender('parent_with_bool_checkbox', [
+            'isActive' => true,
+            'attributes' => ['id' => 'dummy-live-id'],
+        ]);
+
+        // checked attribute must be present (positive assertion — the fix works)
+        $this->assertStringContainsString(' checked', $html);
+
+        // pre-fix symptoms: subscriber must NOT have written value="1" (true cast) or value="" (false cast)
+        $this->assertStringNotContainsString('value="1"', $html);
+        $this->assertStringNotContainsString('value=""', $html);
+    }
 }