From 7304acb17138d136f24e106b22ef3f5713aee4ec Mon Sep 17 00:00:00 2001
From: Steve Boyd <emteknetnz@gmail.com>
Date: Wed, 12 Aug 2020 12:14:05 +1200
Subject: [PATCH] NEW Cache embed shortcodes

---
 _config/cache.yml                             |  5 ++
 .../Shortcodes/EmbedShortcodeProvider.php     | 77 +++++++++++++++++--
 .../Shortcodes/EmbedShortcodeProviderTest.php | 29 +++++++
 3 files changed, 105 insertions(+), 6 deletions(-)

diff --git a/_config/cache.yml b/_config/cache.yml
index 14d65fcea..2372735a9 100644
--- a/_config/cache.yml
+++ b/_config/cache.yml
@@ -37,3 +37,8 @@ SilverStripe\Core\Injector\Injector:
     factory: SilverStripe\Core\Cache\CacheFactory
     constructor:
       namespace: 'DatabaseAdapterRegistry'
+  Psr\SimpleCache\CacheInterface.EmbedShortcodeProvider:
+    factory: SilverStripe\Core\Cache\CacheFactory
+    constructor:
+      namespace: 'EmbedShortcodeProvider'
+      defaultLifetime: 86400
diff --git a/src/View/Shortcodes/EmbedShortcodeProvider.php b/src/View/Shortcodes/EmbedShortcodeProvider.php
index f19529337..8f1cf1929 100644
--- a/src/View/Shortcodes/EmbedShortcodeProvider.php
+++ b/src/View/Shortcodes/EmbedShortcodeProvider.php
@@ -3,7 +3,11 @@
 namespace SilverStripe\View\Shortcodes;
 
 use Embed\Http\DispatcherInterface;
+use League\Flysystem\Exception;
+use Psr\SimpleCache\CacheInterface;
+use Psr\SimpleCache\InvalidArgumentException;
 use SilverStripe\Core\Convert;
+use SilverStripe\Core\Extensible;
 use SilverStripe\Core\Injector\Injector;
 use SilverStripe\ORM\ArrayList;
 use SilverStripe\ORM\FieldType\DBField;
@@ -13,7 +17,6 @@ use SilverStripe\View\Embed\EmbedResource;
 use SilverStripe\View\HTML;
 use SilverStripe\View\Parsers\ShortcodeHandler;
 use Embed\Adapters\Adapter;
-use Embed\Embed;
 use Embed\Exceptions\InvalidUrlException;
 use SilverStripe\View\Parsers\ShortcodeParser;
 use SilverStripe\Control\Director;
@@ -59,6 +62,16 @@ class EmbedShortcodeProvider implements ShortcodeHandler
             return '';
         }
 
+        // Try to use cached result
+        $cache = static::getCache();
+        $key = static::deriveCacheKey($serviceURL);
+        try {
+            if ($cache->has($key)) {
+                return $cache->get($key);
+            }
+        } catch (InvalidArgumentException $e) {
+        }
+
         // See https://github.com/oscarotero/Embed#example-with-all-options for service arguments
         $serviceArguments = [];
         if (!empty($arguments['width'])) {
@@ -113,13 +126,19 @@ class EmbedShortcodeProvider implements ShortcodeHandler
         // Convert embed object into HTML
         if ($embed && $embed instanceof Adapter) {
             $result = static::embedForTemplate($embed, $arguments);
-            if ($result) {
-                return $result;
+        }
+        // Fallback to link to service
+        if (!$result) {
+            $result = static::linkEmbed($arguments, $serviceURL, $serviceURL);
+        }
+        // Cache result
+        if ($result) {
+            try {
+                $cache->set($key, $result);
+            } catch (InvalidArgumentException $e) {
             }
         }
-
-        // Fallback to link to service
-        return static::linkEmbed($arguments, $serviceURL, $serviceURL);
+        return $result;
     }
 
     /**
@@ -242,4 +261,50 @@ class EmbedShortcodeProvider implements ShortcodeHandler
 
         return $attributes;
     }
+
+    /**
+     * @param ShortcodeParser $parser
+     * @param string $content
+     */
+    public static function flushCachedShortcodes(ShortcodeParser $parser, string $content): void
+    {
+        $cache = static::getCache();
+        $tags = $parser->extractTags($content);
+        foreach ($tags as $tag) {
+            if (!isset($tag['open']) || $tag['open'] != 'embed') {
+                continue;
+            }
+            $url = $tag['content'] ?? $tag['attrs']['url'] ?? null;
+            if (!$url) {
+                continue;
+            }
+            $key = static::deriveCacheKey($url);
+            try {
+                if (!$cache->has($key)) {
+                    continue;
+                }
+                $cache->delete($key);
+            } catch (InvalidArgumentException $e) {
+                continue;
+            }
+        }
+    }
+
+    /**
+     * @return CacheInterface
+     */
+    private static function getCache(): CacheInterface
+    {
+        return Injector::inst()->get(CacheInterface::class . '.EmbedShortcodeProvider');
+    }
+
+    /**
+     * @param string $url
+     * @return string
+     */
+    private static function deriveCacheKey(string $url): string
+    {
+        $key = 'embed-shortcode-' . preg_replace('/[^a-zA-Z0-9\-]/', '', $url);
+        return $key;
+    }
 }
diff --git a/tests/php/View/Shortcodes/EmbedShortcodeProviderTest.php b/tests/php/View/Shortcodes/EmbedShortcodeProviderTest.php
index 379970c68..b7d38eb1a 100644
--- a/tests/php/View/Shortcodes/EmbedShortcodeProviderTest.php
+++ b/tests/php/View/Shortcodes/EmbedShortcodeProviderTest.php
@@ -2,6 +2,8 @@
 
 namespace SilverStripe\View\Tests\Shortcodes;
 
+use Psr\SimpleCache\CacheInterface;
+use SilverStripe\View\Parsers\ShortcodeParser;
 use SilverStripe\View\Shortcodes\EmbedShortcodeProvider;
 use SilverStripe\Dev\SapphireTest;
 
@@ -119,4 +121,31 @@ EOS
             ]
         );
     }
+
+    public function testFlushCachedShortcodes()
+    {
+        /** @var CacheInterface $cache */
+        $url = 'http://www.test-service.com/abc123';
+        $content = '<p>Some content with an [embed url="' . $url . '" thumbnail="https://example.com/mythumb.jpg" ' .
+            'class="leftAlone ss-htmleditorfield-file embed" width="480" height="270"]' . $url . '[/embed]</p>';
+        $embedHtml = '<iframe myattr="something" />';
+        $parser = ShortcodeParser::get('default');
+
+        // use reflection to access private methods
+        $provider = new EmbedShortcodeProvider();
+        $reflector = new \ReflectionClass(EmbedShortcodeProvider::class);
+        $method = $reflector->getMethod('getCache');
+        $method->setAccessible(true);
+        $cache = $method->invokeArgs($provider, []);
+        $method = $reflector->getMethod('deriveCacheKey');
+        $method->setAccessible(true);
+        $key = $method->invokeArgs($provider, [$url]);
+
+        // assertions
+        $this->assertEquals('embed-shortcode-httpwwwtest-servicecomabc123', $key);
+        $cache->set($key, $embedHtml);
+        $this->assertTrue($cache->has($key));
+        EmbedShortcodeProvider::flushCachedShortcodes($parser, $content);
+        $this->assertFalse($cache->has($key));
+    }
 }