Initial commit

typo3conf/ext/vhs/Classes/ViewHelpers/Once/AbstractOnceViewHelper.php

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+<?php
+namespace FluidTYPO3\Vhs\ViewHelpers\Once;
+
+/*
+ * 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\Fluid\Core\ViewHelper\AbstractConditionViewHelper;
+
+/**
+ * Base class for "Render Once"-style ViewHelpers: session, cookie,
+ * request, template variable set, ViewHelper variable set etc.
+ *
+ * @author Claus Due <claus@namelesscoder.net>
+ * @package Vhs
+ * @subpackage ViewHelpers\Once
+ */
+abstract class AbstractOnceViewHelper extends AbstractConditionViewHelper {
+
+	/**
+	 * Standard storage - static variable meaning uniqueness of $identifier
+	 * across each Request, i.e. unique to each individual plugin/content.
+	 *
+	 * @var array
+	 */
+	protected static $identifiers = array();
+
+	/**
+	 * Initialize arguments
+	 *
+	 * @return void
+	 */
+	public function initializeArguments() {
+		parent::initializeArguments();
+		$this->registerArgument('identifier', 'string', 'Identity of this condition - if used in other places, the condition applies to the same identity in the storage (i.e. cookie name or session key)');
+		$this->registerArgument('lockToDomain', 'boolean', 'If TRUE, locks this condition to a specific domain, i.e. the storage of $identity is associated with a domain. If same identity is also used without domain lock, it matches any domain locked condition', FALSE, FALSE);
+		$this->registerArgument('ttl', 'integer', 'Time-to-live for skip registration, number of seconds. After this expires the registration is unset', FALSE, 86400);
+	}
+
+	/**
+	 * Standard render method. Implementers should override
+	 * the assertShouldSkip() method and/or the getIdentifier()
+	 * and storeIdentifier() methods as applies to each
+	 * implementers method of storing identifiers.
+	 *
+	 * @return string
+	 */
+	public function render() {
+		$this->removeIfExpired();
+		$evaluation = $this->assertShouldSkip();
+		if (FALSE === $evaluation) {
+			$content = $this->renderThenChild();
+		} else {
+			$content = $this->renderElseChild();
+		}
+		$this->storeIdentifier();
+		return $content;
+	}
+
+	/**
+	 * @return string
+	 */
+	protected function getIdentifier() {
+		if (TRUE === isset($this->arguments['identifier'])) {
+			return $this->arguments['identifier'];
+		}
+		return get_class($this);
+	}
+
+	/**
+	 * @retrun void
+	 */
+	protected function storeIdentifier() {
+		$identifier = $this->getIdentifier();
+		if (FALSE === isset(self::$identifiers[$identifier])) {
+			self::$identifiers[$identifier] = time();
+		}
+	}
+
+	/**
+	 * @return void
+	 */
+	protected function removeIfExpired() {
+		$identifier = $this->getIdentifier();
+		if (TRUE === isset(self::$identifiers[$identifier]) && self::$identifiers[$identifier] <= time() - $this->arguments['ttl']) {
+			unset(self::$identifiers[$identifier]);
+		}
+	}
+
+	/**
+	 * @return boolean
+	 */
+	protected function assertShouldSkip() {
+		$identifier = $this->getIdentifier();
+		return (TRUE === isset(self::$identifiers[$identifier]));
+	}
+
+	/**
+	 * Override: forcibly disables page caching - a TRUE condition
+	 * in this ViewHelper means page content would be depending on
+	 * the current visitor's session/cookie/auth etc.
+	 *
+	 * Returns value of "then" attribute.
+	 * If then attribute is not set, iterates through child nodes and renders ThenViewHelper.
+	 * If then attribute is not set and no ThenViewHelper and no ElseViewHelper is found, all child nodes are rendered
+	 *
+	 * @return string rendered ThenViewHelper or contents of <f:if> if no ThenViewHelper was found
+	 * @api
+	 */
+	protected function renderThenChild() {
+		$GLOBALS['TSFE']->no_cache = 1;
+		return parent::renderThenChild();
+	}
+
+}