[LazyImage] Abstract image content fetching

Author: Kocal

src/LazyImage/doc/index.rst

@@ -99,10 +99,38 @@ blurred, data-uri thumbnail of the image:
 
 The ``data_uri_thumbnail`` function receives 3 arguments:
 
--  the server path to the image to generate the data-uri thumbnail for ;
+-  the path to the image to generate the data-uri thumbnail for ;
 -  the width of the BlurHash to generate
 -  the height of the BlurHash to generate
 
+Customizing images fetching
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+By default, ``data_uri_thumbnail`` fetches images using the `file_get_contents`_ function.
+It works well for local files, but you may want to customize it to fetch images from a remote server, `Flysystem`_, etc.
+
+To do so you can create a invokable class, the first argument is the filename to fetch:
+
+.. ::
+
+    namespace App\BlurHash;
+
+    class FetchImageContent
+    {
+        public function __invoke(string $filename): string
+        {
+            // Your custom implementation here to fetch the image content
+        }
+    }
+
+Then you must configure the service in your Symfony configuration:
+
+.. code-block:: yaml
+
+    # config/packages/lazy_image.yaml
+    lazy_image:
+        fetch_image_content: 'App\BlurHash\FetchImageContent'
+
 Performance considerations
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -190,3 +218,5 @@ https://symfony.com/doc/current/contributing/code/bc.html
 .. _`BlurHash implementation`: https://blurha.sh
 .. _`StimulusBundle`: https://symfony.com/bundles/StimulusBundle/current/index.html
 .. _StimulusBundle configured in your app: https://symfony.com/bundles/StimulusBundle/current/index.html
+.. _`file_get_contents`: https://www.php.net/manual/en/function.file-get-contents.php
+.. _`Flysystem`: https://flysystem.thephpleague.com

src/LazyImage/src/BlurHash/BlurHash.php

@@ -25,10 +25,17 @@
  */
 class BlurHash implements BlurHashInterface
 {
+    private \Closure $fetchImageContent;
+
+    /**
+     * @param (\Closure(string): string)|null $fetchImageContent
+     */
     public function __construct(
         private ?ImageManager $imageManager = null,
         private ?CacheInterface $cache = null,
+        ?callable $fetchImageContent = null,
     ) {
+        $this->fetchImageContent = $fetchImageContent ? $fetchImageContent(...) : file_get_contents(...);
     }
 
     public static function intervention3(): bool
@@ -74,8 +81,10 @@ private function doEncode(string $filename, int $encodingWidth = 75, int $encodi
 
     private function generatePixels(string $filename, int $encodingWidth, int $encodingHeight): array
     {
+        $imageContent = ($this->fetchImageContent)($filename);
+
         if (self::intervention3()) {
-            $image = $this->imageManager->read($filename)->scale($encodingWidth, $encodingHeight);
+            $image = $this->imageManager->read($imageContent)->scale($encodingWidth, $encodingHeight);
             $width = $image->width();
             $height = $image->height();
             $pixels = [];
@@ -93,7 +102,7 @@ private function generatePixels(string $filename, int $encodingWidth, int $encod
         }
 
         // Resize image to increase encoding performance
-        $image = $this->imageManager->make(file_get_contents($filename));
+        $image = $this->imageManager->make($imageContent);
         $image->resize($encodingWidth, $encodingHeight, static function ($constraint) {
             $constraint->aspectRatio();
             $constraint->upsize();

src/LazyImage/src/DependencyInjection/Configuration.php

@@ -28,6 +28,7 @@ public function getConfigTreeBuilder(): TreeBuilder
         $rootNode
             ->children()
                 ->scalarNode('cache')->end()
+                ->scalarNode('fetch_image_content')->defaultNull()->end()
             ->end()
         ;
 

src/LazyImage/src/DependencyInjection/LazyImageExtension.php

@@ -46,7 +46,11 @@ public function load(array $configs, ContainerBuilder $container)
 
         $container
             ->setDefinition('lazy_image.blur_hash', new Definition(BlurHash::class))
-            ->setArgument(0, new Reference('lazy_image.image_manager', ContainerInterface::NULL_ON_INVALID_REFERENCE))
+            ->setArguments([
+                new Reference('lazy_image.image_manager', ContainerInterface::NULL_ON_INVALID_REFERENCE),
+                null, // $cache
+                null, // $fetchImageContent
+            ])
         ;
 
         if (isset($config['cache'])) {
@@ -56,6 +60,13 @@ public function load(array $configs, ContainerBuilder $container)
             ;
         }
 
+        if (isset($config['fetch_image_content'])) {
+            $container
+                ->getDefinition('lazy_image.blur_hash')
+                ->setArgument(2, new Reference($config['fetch_image_content']))
+            ;
+        }
+
         $container->setAlias(BlurHashInterface::class, 'lazy_image.blur_hash')->setPublic(false);
 
         $container

src/LazyImage/tests/BlurHash/BlurHashTest.php

@@ -15,9 +15,11 @@
 use Symfony\Component\Cache\Adapter\ArrayAdapter;
 use Symfony\Component\Config\Loader\LoaderInterface;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Definition;
 use Symfony\Contracts\Cache\CacheInterface;
 use Symfony\UX\LazyImage\BlurHash\BlurHash;
 use Symfony\UX\LazyImage\BlurHash\BlurHashInterface;
+use Symfony\UX\LazyImage\Tests\Fixtures\BlurHash\LoggedFetchImageContent;
 use Symfony\UX\LazyImage\Tests\Kernel\TwigAppKernel;
 
 /**
@@ -42,6 +44,45 @@ public function testEncode()
         );
     }
 
+    public function testWithCustomGetImageContent(): void
+    {
+        $kernel = new class('test', true) extends TwigAppKernel {
+            public function registerContainerConfiguration(LoaderInterface $loader)
+            {
+                parent::registerContainerConfiguration($loader);
+
+                $loader->load(static function (ContainerBuilder $container) {
+                    $container->loadFromExtension('lazy_image', [
+                        'fetch_image_content' => 'logged_get_image_content',
+                    ]);
+
+                    $container
+                        ->setDefinition('logged_get_image_content', new Definition(LoggedFetchImageContent::class))
+                        ->setPublic('true')
+                    ;
+                });
+            }
+        };
+
+        $kernel->boot();
+        $container = $kernel->getContainer()->get('test.service_container');
+
+        /** @var BlurHashInterface $blurHash */
+        $blurHash = $container->get('test.lazy_image.blur_hash');
+
+        $loggedGetImageContent = $container->get('logged_get_image_content');
+        $this->assertInstanceOf(LoggedFetchImageContent::class, $loggedGetImageContent);
+        $this->assertEmpty($loggedGetImageContent->logs);
+
+        $this->assertSame(
+            BlurHash::intervention3() ? 'LnMtaO9FD%IU%MRjayRj~qIUM{of' : 'L54ec*~q_3?bofoffQWB9F9FD%IU',
+            $blurHash->encode(__DIR__.'/../Fixtures/logo.png')
+        );
+
+        $this->assertCount(1, $loggedGetImageContent->logs);
+        $this->assertSame(__DIR__.'/../Fixtures/logo.png', $loggedGetImageContent->logs[0]);
+    }
+
     public function testEnsureCacheIsNotUsedWhenNotConfigured()
     {
         $kernel = new TwigAppKernel('test', true);

src/LazyImage/tests/Fixtures/BlurHash/LoggedFetchImageContent.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace Symfony\UX\LazyImage\Tests\Fixtures\BlurHash;
+
+final class LoggedFetchImageContent
+{
+    public array $logs = [];
+
+    public function __invoke(string $filename): string
+    {
+        $this->logs[] = $filename;
+
+        return file_get_contents($filename);
+    }
+}