symfony · weaverryan · Aug 18, 2023 · May 30, 2023
diff --git a/src/LiveComponent/src/DependencyInjection/LiveComponentExtension.php b/src/LiveComponent/src/DependencyInjection/LiveComponentExtension.php
@@ -37,6 +37,8 @@
 use Symfony\UX\LiveComponent\Twig\DeterministicTwigIdCalculator;
 use Symfony\UX\LiveComponent\Twig\LiveComponentExtension as LiveComponentTwigExtension;
 use Symfony\UX\LiveComponent\Twig\LiveComponentRuntime;
+use Symfony\UX\LiveComponent\Twig\TemplateCacheWarmer;
+use Symfony\UX\LiveComponent\Twig\TemplateMap;
 use Symfony\UX\LiveComponent\Util\ChildComponentPartialRenderer;
 use Symfony\UX\LiveComponent\Util\FingerprintCalculator;
 use Symfony\UX\LiveComponent\Util\LiveControllerAttributesCreator;
@@ -55,6 +57,8 @@
  */
 final class LiveComponentExtension extends Extension implements PrependExtensionInterface
 {
+    public const TEMPLATES_MAP_FILENAME = 'live_components_twig_templates.map';
+
     public function prepend(ContainerBuilder $container)
     {
         // Register the form theme if TwigBundle is available
@@ -190,12 +194,14 @@ function (ChildDefinition $definition, AsLiveComponent $attribute) {
                 new Reference('router'),
                 new Reference('ux.live_component.live_responder'),
                 new Reference('security.csrf.token_manager', ContainerInterface::NULL_ON_INVALID_REFERENCE),
+                new Reference('ux.live_component.twig.template_mapper'),
             ])
         ;
 
         $container->register('ux.live_component.add_attributes_subscriber', AddLiveAttributesSubscriber::class)
             ->setArguments([
                 new Reference('ux.twig_component.component_stack'),
+                new Reference('ux.live_component.twig.template_mapper'),
             ])
             ->addTag('kernel.event_subscriber')
             ->addTag('container.service_subscriber', ['key' => LiveControllerAttributesCreator::class, 'id' => 'ux.live_component.live_controller_attributes_creator'])
@@ -212,6 +218,13 @@ function (ChildDefinition $definition, AsLiveComponent $attribute) {
             ->addTag('form.type')
             ->setPublic(false)
         ;
+
+        $container->register('ux.live_component.twig.template_mapper', TemplateMap::class)
+            ->setArguments(['%kernel.cache_dir%/'.self::TEMPLATES_MAP_FILENAME]);
+
+        $container->register('ux.live_component.twig.cache_warmer', TemplateCacheWarmer::class)
+            ->setArguments([new Reference('twig.template_iterator'), self::TEMPLATES_MAP_FILENAME])
+            ->addTag('kernel.cache_warmer');
     }
 
     private function isAssetMapperAvailable(ContainerBuilder $container): bool

diff --git a/src/LiveComponent/src/EventListener/AddLiveAttributesSubscriber.php b/src/LiveComponent/src/EventListener/AddLiveAttributesSubscriber.php
@@ -14,6 +14,7 @@
 use Psr\Container\ContainerInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Contracts\Service\ServiceSubscriberInterface;
+use Symfony\UX\LiveComponent\Twig\TemplateMap;
 use Symfony\UX\LiveComponent\Util\LiveControllerAttributesCreator;
 use Symfony\UX\TwigComponent\ComponentAttributes;
 use Symfony\UX\TwigComponent\ComponentMetadata;
@@ -36,7 +37,8 @@ final class AddLiveAttributesSubscriber implements EventSubscriberInterface, Ser
 {
     public function __construct(
         private ComponentStack $componentStack,
-        private ContainerInterface $container
+        private TemplateMap $templateMap,
+        private ContainerInterface $container,
     ) {
     }
 
@@ -47,10 +49,6 @@ public function onPreRender(PreRenderEvent $event): void
             return;
         }
 
-        if ($event->isEmbedded()) {
-            throw new \LogicException('Embedded components cannot be live.');
-        }
-
         $metadata = $event->getMetadata();
         $attributes = $this->getLiveAttributes($event->getMountedComponent(), $metadata);
         $variables = $event->getVariables();
@@ -60,8 +58,21 @@ public function onPreRender(PreRenderEvent $event): void
         // onto the variables. So, we manually merge our new attributes in and
         // override that variable.
         if (isset($variables[$attributesKey]) && $variables[$attributesKey] instanceof ComponentAttributes) {
+            $originalAttributes = $variables[$attributesKey]->all();
+
             // merge with existing attributes if available
-            $attributes = $attributes->defaults($variables[$attributesKey]->all());
+            $attributes = $attributes->defaults($originalAttributes);
+
+            if (isset($originalAttributes['data-host-template'], $originalAttributes['data-embedded-template-index'])) {
+                // This component is an embedded component, that's being re-rendered.
+                // We'll change the template that will be used to render it to
+                // the embedded template so that the blocks from that template
+                // will be used, if any, instead of the originals.
+                $event->setTemplate(
+                    $this->templateMap->resolve($originalAttributes['data-host-template']),
+                    $originalAttributes['data-embedded-template-index'],
+                );
+            }
         }
 
         // "key" is a special attribute: don't actually render it

diff --git a/src/LiveComponent/src/Twig/TemplateCacheWarmer.php b/src/LiveComponent/src/Twig/TemplateCacheWarmer.php
@@ -0,0 +1,43 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\UX\LiveComponent\Twig;
+
+use Symfony\Component\Cache\Adapter\NullAdapter;
+use Symfony\Component\Cache\Adapter\PhpArrayAdapter;
+use Symfony\Component\HttpKernel\CacheWarmer\CacheWarmerInterface;
+
+/**
+ * @author Bart Vanderstukken <bart.vanderstukken@gmail.com>
+ *
+ * @internal
+ */
+final class TemplateCacheWarmer implements CacheWarmerInterface
+{
+    public function __construct(private \IteratorAggregate $templateIterator, private readonly string $cacheFilename)
+    {
+    }
+
+    public function warmUp(string $cacheDir): void
+    {
+        $map = [];
+        foreach ($this->templateIterator as $item) {
+            $map[bin2hex(random_bytes(16))] = $item;
+        }
+
+        (new PhpArrayAdapter($cacheDir.'/'.$this->cacheFilename, new NullAdapter()))->warmUp(['map' => $map]);
+    }
+
+    public function isOptional(): bool
+    {
+        return false;
+    }
+}
diff --git a/src/LiveComponent/src/Twig/TemplateMap.php b/src/LiveComponent/src/Twig/TemplateMap.php
@@ -0,0 +1,45 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\UX\LiveComponent\Twig;
+
+use Symfony\Component\Cache\Adapter\NullAdapter;
+use Symfony\Component\Cache\Adapter\PhpArrayAdapter;
+
+/**
+ * @author Bart Vanderstukken <bart.vanderstukken@gmail.com>
+ *
+ * @internal
+ */
+final class TemplateMap
+{
+    private readonly array $map;
+
+    public function __construct(string $cacheFile)
+    {
+        $this->map = (new PhpArrayAdapter($cacheFile, new NullAdapter()))->getItem('map')->get();
+    }
+
+    public function resolve(string $obscuredName)
+    {
+        return $this->map[$obscuredName] ?? throw new \RuntimeException(sprintf('Cannot find a template matching "%s". Cache may be corrupt.', $obscuredName));
+    }
+
+    public function obscuredName(string $templateName): string
+    {
+        $obscuredName = array_search($templateName, $this->map, true);
+        if (false === $obscuredName) {
+            throw new \RuntimeException(sprintf('Cannot find a match for template "%s". Cache may be corrupt.', $templateName));
+        }
+
+        return $obscuredName;
+    }
+}
diff --git a/src/LiveComponent/src/Util/LiveControllerAttributesCreator.php b/src/LiveComponent/src/Util/LiveControllerAttributesCreator.php
@@ -18,6 +18,7 @@
 use Symfony\UX\LiveComponent\LiveResponder;
 use Symfony\UX\LiveComponent\Metadata\LiveComponentMetadataFactory;
 use Symfony\UX\LiveComponent\Twig\DeterministicTwigIdCalculator;
+use Symfony\UX\LiveComponent\Twig\TemplateMap;
 use Symfony\UX\TwigComponent\ComponentAttributes;
 use Symfony\UX\TwigComponent\ComponentMetadata;
 use Symfony\UX\TwigComponent\MountedComponent;
@@ -47,6 +48,7 @@ public function __construct(
         private UrlGeneratorInterface $urlGenerator,
         private LiveResponder $liveResponder,
         private ?CsrfTokenManagerInterface $csrfTokenManager,
+        private TemplateMap $templateMap,
     ) {
     }
 
@@ -80,16 +82,23 @@ public function attributesForRendering(MountedComponent $mounted, ComponentMetad
 
         $mountedAttributes = $mounted->getAttributes();
 
-        if ($isChildComponent) {
-            if (!isset($mountedAttributes->all()['data-live-id'])) {
-                $id = $deterministicId ?: $this->idCalculator
-                    ->calculateDeterministicId(key: $mounted->getInputProps()[self::KEY_PROP_NAME] ?? null);
-                $attributesCollection->setLiveId($id);
-                // we need to add this to the mounted attributes so that it is
-                // will be included in the "attributes" part of the props data.
-                $mountedAttributes = $mountedAttributes->defaults(['data-live-id' => $id]);
-            }
+        if ($mounted->hasExtraMetadata('hostTemplate') && $mounted->hasExtraMetadata('embeddedTemplateIndex')) {
+            $mountedAttributes = $mountedAttributes->defaults([
+                'data-host-template' => $this->templateMap->obscuredName($mounted->getExtraMetadata('hostTemplate')),
+                'data-embedded-template-index' => $mounted->getExtraMetadata('embeddedTemplateIndex'),
+            ]);
+        }
 
+        if (!isset($mountedAttributes->all()['data-live-id'])) {
+            $id = $deterministicId ?: $this->idCalculator
+                ->calculateDeterministicId(key: $mounted->getInputProps()[self::KEY_PROP_NAME] ?? null);
+            $attributesCollection->setLiveId($id);
+            // we need to add this to the mounted attributes so that it is
+            // will be included in the "attributes" part of the props data.
+            $mountedAttributes = $mountedAttributes->defaults(['data-live-id' => $id]);
+        }
+
+        if ($isChildComponent) {
             $fingerprint = $this->fingerprintCalculator->calculateFingerprint(
                 $mounted->getInputProps(),
                 $this->metadataFactory->getMetadata($mounted->getName())

diff --git a/src/LiveComponent/tests/Fixtures/templates/components/component2.html.twig b/src/LiveComponent/tests/Fixtures/templates/components/component2.html.twig
@@ -1,4 +1,6 @@
-<div{{ attributes }}>
+<div{{ attributes.defaults({class: 'component2'}) }} >
+    {% block content %}
     Count: {{ this.count }}
     PreReRenderCalled: {{ this.preReRenderCalled ? 'Yes' : 'No' }}
+    {% endblock %}
 </div>
diff --git a/src/LiveComponent/tests/Fixtures/templates/components/todo_list.html.twig b/src/LiveComponent/tests/Fixtures/templates/components/todo_list.html.twig
@@ -7,7 +7,11 @@
         {% if includeDataLiveId %}
             {% set componentProps = componentProps|merge({'data-live-id': ('todo-item-' ~ loop.index) }) %}
         {% endif %}
-        {{ component('todo_item', componentProps) }}
+        {% if loop.index is odd %}
+            {{ component('todo_item', componentProps) }}
+        {% else %}
+            {% component 'todo_item' with componentProps %}{% endcomponent %}
+        {% endif %}
     {% endfor %}
     </ul>
 </div>
diff --git a/src/LiveComponent/tests/Fixtures/templates/components/todo_list_with_keys.html.twig b/src/LiveComponent/tests/Fixtures/templates/components/todo_list_with_keys.html.twig
@@ -3,7 +3,11 @@
 
     <ul>
     {% for key, item in items %}
-        {{ component('todo_item', { text: item.text, textLength: item.text|length, key: 'the-key'~key }) }}
+        {% if loop.index is odd %}
+            {{ component('todo_item', { text: item.text, textLength: item.text|length, key: 'the-key'~key }) }}
+        {% else %}
+            {% component 'todo_item' with { text: item.text, textLength: item.text|length, key: 'the-key'~key } %}{% endcomponent %}
+        {% endif %}
     {% endfor %}
     </ul>
 </div>
diff --git a/src/LiveComponent/tests/Fixtures/templates/render_embedded_with_blocks.html.twig b/src/LiveComponent/tests/Fixtures/templates/render_embedded_with_blocks.html.twig
@@ -0,0 +1,6 @@
+{% component component2 %}
+    {% block content %}
+        {{ parent() }}
+        Embedded content with access to context, like count={{ this.count }}
+    {% endblock %}
+{% endcomponent %}
diff --git a/src/LiveComponent/tests/Fixtures/templates/render_multiple_embedded_with_blocks.html.twig b/src/LiveComponent/tests/Fixtures/templates/render_multiple_embedded_with_blocks.html.twig
@@ -0,0 +1,2 @@
+<div id="component1">{% component component2 %}{% block content %}Overridden content from component 1{% endblock %}{% endcomponent %}</div><div id="component2">{% component component2 %}{% block content %}Overridden content from component 2 on same line - count: {{ this.count }}{% endblock %}{% endcomponent %}</div>
+<div id="component3">Not overriding{% component component2 %}{% endcomponent %}</div>
diff --git a/src/LiveComponent/tests/Functional/EventListener/AddLiveAttributesSubscriberTest.php b/src/LiveComponent/tests/Functional/EventListener/AddLiveAttributesSubscriberTest.php
@@ -12,6 +12,7 @@
 namespace Symfony\UX\LiveComponent\Tests\Functional\EventListener;
 
 use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
+use Symfony\UX\LiveComponent\Tests\LiveComponentTestHelper;
 use Zenstruck\Browser\Test\HasBrowser;
 
 /**
@@ -20,11 +21,14 @@
 final class AddLiveAttributesSubscriberTest extends KernelTestCase
 {
     use HasBrowser;
+    use LiveComponentTestHelper;
+
     /**
      * The deterministic id of the "todo_item" components in todo_list.html.twig.
      * If that template changes, this will need to be updated.
      */
-    public const TODO_ITEM_DETERMINISTIC_PREFIX = 'live-289310975-';
+    public const TODO_ITEM_DETERMINISTIC_PREFIX = 'live-1715058793-';
+    public const TODO_ITEM_DETERMINISTIC_PREFIX_EMBEDDED = 'live-2285361477-';
 
     public function testInitLiveComponent(): void
     {
@@ -40,10 +44,12 @@ public function testInitLiveComponent(): void
         $this->assertSame('live', $div->attr('data-controller'));
         $this->assertSame('/_components/component_with_writable_props', $div->attr('data-live-url-value'));
         $this->assertNotNull($div->attr('data-live-csrf-value'));
-        $this->assertCount(3, $props);
+        $this->assertCount(4, $props);
         $this->assertSame(5, $props['max']);
         $this->assertSame(1, $props['count']);
         $this->assertArrayHasKey('@checksum', $props);
+        $this->assertArrayHasKey('@attributes', $props);
+        $this->assertArrayHasKey('data-live-id', $props['@attributes']);
     }
 
     public function testCanUseCustomAttributesVariableName(): void
@@ -79,6 +85,10 @@ public function testCanDisableCsrf(): void
 
     public function testItAddsIdAndFingerprintToChildComponent(): void
     {
+        $templateName = 'components/todo_list.html.twig';
+        $obscuredName = 'd9bcb8935cbb4282ac5d227fc82ae782';
+        $this->addTemplateMap($obscuredName, $templateName);
+
         $ul = $this->browser()
             ->visit('/render-template/render_todo_list')
             ->assertSuccessful()
@@ -89,7 +99,7 @@ public function testItAddsIdAndFingerprintToChildComponent(): void
         $lis = $ul->children('li');
         // deterministic id: should not change, and counter should increase
         $this->assertSame(self::TODO_ITEM_DETERMINISTIC_PREFIX.'0', $lis->first()->attr('data-live-id'));
-        $this->assertSame(self::TODO_ITEM_DETERMINISTIC_PREFIX.'2', $lis->last()->attr('data-live-id'));
+        $this->assertSame(self::TODO_ITEM_DETERMINISTIC_PREFIX.'1', $lis->last()->attr('data-live-id'));
 
         // the data-live-id attribute also needs to be part of the "props" so that it persists on renders
         $props = json_decode($lis->first()->attr('data-live-props-value'), true);
@@ -107,6 +117,10 @@ public function testItAddsIdAndFingerprintToChildComponent(): void
 
     public function testItDoesNotOverrideDataLiveIdIfSpecified(): void
     {
+        $templateName = 'components/todo_list.html.twig';
+        $obscuredName = 'a643d58357b14c9bb077f0c00a742059';
+        $this->addTemplateMap($obscuredName, $templateName);
+
         $ul = $this->browser()
             ->visit('/render-template/render_todo_list_with_live_id')
             ->assertSuccessful()
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		<div id="component1">{% component component2 %}{% block content %}Overridden content from component 1{% endblock %}{% endcomponent %}</div><div id="component2">{% component component2 %}{% block content %}Overridden content from component 2 on same line - count: {{ this.count }}{% endblock %}{% endcomponent %}</div>
		<div id="component3">Not overriding{% component component2 %}{% endcomponent %}</div>