Initial commit

typo3conf/ext/vhs/Classes/ViewHelpers/Render/CacheViewHelper.php

@@ -0,0 +1,132 @@
+<?php
+namespace FluidTYPO3\Vhs\ViewHelpers\Render;
+
+/*
+ * This file is part of the FluidTYPO3/Vhs project under GPLv2 or later.
+ *
+ * For the full copyright and license information, please read the
+ * LICENSE.md file that was distributed with this source code.
+ */
+
+use TYPO3\CMS\Core\Utility\GeneralUtility;
+use TYPO3\CMS\Extbase\DomainObject\DomainObjectInterface;
+
+/**
+ * ### Cache Rendering ViewHelper
+ *
+ * Caches the child content (any type supported as long as it
+ * can be serialized). Because of the added overhead you should
+ * only use this if what you are caching is complex enough that
+ * it performs many DB request (for example when displaying an
+ * object with many lazy properties which don't load until the
+ * template asks for the property value). In short, applies to
+ * just about the same use cases as any other cache - but remember
+ * that Fluid is already a very efficient rendering engine so don't
+ * just assume that using the ViewHelper will increase performance
+ * or decrease memory usage.
+ *
+ * Works forcibly, i.e. can only re-render its content if the
+ * cache is cleared. A CTRL+Refresh in the browser does nothing,
+ * even if a BE user is logged in. Only use this ViewHelper around
+ * content which you are absolutely sure it makes sense to cache
+ * along with an identity - for example, if rendering an uncached
+ * plugin which contains a Partial template that is in all aspects
+ * just a solid-state HTML representation of something like a list
+ * of current news.
+ *
+ * The cache behind this ViewHelper is the Extbase object cache,
+ * which is cleared when you clear the page content cache.
+ *
+ * Do not use on form elements, it will invalidate the checksum.
+ *
+ * Do not use around ViewHelpers which add header data or which
+ * interact with the PageRenderer or other "live" objects; this
+ * includes many of the VHS ViewHelpers!
+ *
+ * @author Claus Due <claus@namelesscoder.net>
+ * @package Vhs
+ * @subpackage ViewHelpers\Render
+ */
+class CacheViewHelper extends AbstractRenderViewHelper {
+
+	const ID_PREFIX = 'vhs-render-cache-viewhelper';
+
+	const ID_SEPARATOR = '-';
+
+	/**
+	 * @var \TYPO3\CMS\Core\Cache\Frontend\StringFrontend
+	 */
+	protected $cache;
+
+	/**
+	 * @return void
+	 */
+	public function initialize() {
+		$cacheManager = isset($GLOBALS['typo3CacheManager']) ? $GLOBALS['typo3CacheManager'] : GeneralUtility::makeInstance('TYPO3\\CMS\\Core\\Cache\\CacheManager');
+		$this->cache = $cacheManager->getCache('vhs_main');
+	}
+
+	/**
+	 * Render
+	 *
+	 * @param mixed $identity Identifier for the cached content (usage preferred)
+	 * @param mixed $content Value to be cached
+	 * @return mixed
+	 * @throws \RuntimeException
+	 */
+	public function render($identity, $content = NULL) {
+		if (FALSE === ctype_alnum(preg_replace('/[\-_]/i', '', $identity))) {
+			if (TRUE === $identity instanceof DomainObjectInterface) {
+				$identity = get_class($identity) . self::ID_SEPARATOR . $identity->getUid();
+			} elseif (TRUE === method_exists($identity, '__toString')) {
+				$identity = (string) $identity;
+			} else {
+				throw new \RuntimeException(
+					'Parameter $identity for Render/CacheViewHelper was not a string or a string-convertible object',
+					1352581782
+				);
+			}
+		}
+
+		// Hash the cache-key to circumvent disallowed chars
+		$identity = sha1($identity);
+
+		if (TRUE === $this->has($identity)) {
+			return $this->retrieve($identity);
+		}
+		if (NULL === $content) {
+			$content = $this->renderChildren();
+		}
+		$this->store($content, $identity);
+		return $content;
+	}
+
+	/**
+	 * @param string $id
+	 * @return boolean
+	 */
+	protected function has($id) {
+		return (boolean) $this->cache->has(self::ID_PREFIX . self::ID_SEPARATOR . $id);
+	}
+
+	/**
+	 * @param mixed $value
+	 * @param string $id
+	 * @return void
+	 */
+	protected function store($value, $id) {
+		$this->cache->set(self::ID_PREFIX . self::ID_SEPARATOR . $id, $value);
+	}
+
+	/**
+	 * @param string $id
+	 * @return mixed
+	 */
+	protected function retrieve($id) {
+		if ($this->cache->has(self::ID_PREFIX . self::ID_SEPARATOR . $id)) {
+			return $this->cache->get(self::ID_PREFIX . self::ID_SEPARATOR . $id);
+		}
+		return NULL;
+	}
+
+}