AbstractConditionViewHelper.php

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<?php

/*                                                                        *
 * This script belongs to the FLOW3 package "Fluid".                      *
 *                                                                        *
 * It is free software; you can redistribute it and/or modify it under    *
 * the terms of the GNU Lesser General Public License as published by the *
 * Free Software Foundation, either version 3 of the License, or (at your *
 * option) any later version.                                             *
 *                                                                        *
 * This script is distributed in the hope that it will be useful, but     *
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHAN-    *
 * TABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser       *
 * General Public License for more details.                               *
 *                                                                        *
 * You should have received a copy of the GNU Lesser General Public       *
 * License along with the script.                                         *
 * If not, see http://www.gnu.org/licenses/lgpl.html                      *
 *                                                                        *
 * The TYPO3 project - inspiring people to share!                         *
 *                                                                        */

/**
 * This view helper is an abstract ViewHelper which implements an if/else condition.
 * @see Tx_Fluid_Core_Parser_SyntaxTree_ViewHelperNode::convertArgumentValue() to find see how boolean arguments are evaluated
 *
 * = Usage =
 *
 * To create a custom Condition ViewHelper, you need to subclass this class, and
 * implement your own render() method. Inside there, you should call $this->renderThenChild()
 * if the condition evaluated to TRUE, and $this->renderElseChild() if the condition evaluated
 * to FALSE.
 *
 * Every Condition ViewHelper has a "then" and "else" argument, so it can be used like:
 * <[aConditionViewHelperName] .... then="condition true" else="condition false" />,
 * or as well use the "then" and "else" child nodes.
 *
 * @see Tx_Fluid_ViewHelpers_IfViewHelper for a more detailed explanation and a simple usage example.
 * Make sure to NOT OVERRIDE the constructor.
 *
 * @license http://www.gnu.org/licenses/lgpl.html GNU Lesser General Public License, version 3 or later
 * @api
 */
abstract class Tx_Fluid_Core_ViewHelper_AbstractConditionViewHelper extends Tx_Fluid_Core_ViewHelper_AbstractViewHelper implements Tx_Fluid_Core_ViewHelper_Facets_ChildNodeAccessInterface {

    /**
     * An array of Tx_Fluid_Core_Parser_SyntaxTree_AbstractNode
     * @var array
     */
    private $childNodes = array();

    /**
     * Setter for ChildNodes - as defined in ChildNodeAccessInterface
     *
     * @param array $childNodes Child nodes of this syntax tree node
     * @return void
     * @author Sebastian Kurfürst <sebastian@typo3.org>
     */
    public function setChildNodes(array $childNodes) {
        $this->childNodes = $childNodes;
    }

    /**
     * Initializes the "then" and "else" arguments
     *
     * @author Sebastian Kurfürst <sebastian@typo3.org>
     */
    public function __construct() {
        $this->registerArgument('then', 'mixed', 'Value to be returned if the condition if met.', FALSE);
        $this->registerArgument('else', 'mixed', 'Value to be returned if the condition if not met.', FALSE);
    }

    /**
     * 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 is found, all child nodes are rendered
     *
     * @return string rendered ThenViewHelper or contents of <f:if> if no ThenViewHelper was found
     * @author Sebastian Kurfürst <sebastian@typo3.org>
     * @author Bastian Waidelich <bastian@typo3.org>
     * @api
     */
    protected function renderThenChild() {
        if ($this->arguments->hasArgument('then')) {
            return $this->arguments['then'];
        }
        foreach ($this->childNodes as $childNode) {
            if ($childNode instanceof Tx_Fluid_Core_Parser_SyntaxTree_ViewHelperNode
                && $childNode->getViewHelperClassName() === 'Tx_Fluid_ViewHelpers_ThenViewHelper') {
                $data = $childNode->evaluate($this->getRenderingContext());
                return $data;
            }
        }
        return $this->renderChildren();
    }

    /**
     * Returns value of "else" attribute.
     * If else attribute is not set, iterates through child nodes and renders ElseViewHelper.
     * If else attribute is not set and no ElseViewHelper is found, an empty string will be returned.
     *
     * @return string rendered ElseViewHelper or an empty string if no ThenViewHelper was found
     * @author Sebastian Kurfürst <sebastian@typo3.org>
     * @author Bastian Waidelich <bastian@typo3.org>
     * @api
     */
    protected function renderElseChild() {
        foreach ($this->childNodes as $childNode) {
            if ($childNode instanceof Tx_Fluid_Core_Parser_SyntaxTree_ViewHelperNode
                && $childNode->getViewHelperClassName() === 'Tx_Fluid_ViewHelpers_ElseViewHelper') {
                return $childNode->evaluate($this->getRenderingContext());
            }
        }
        if ($this->arguments->hasArgument('else')) {
            return $this->arguments['else'];
        }
        return '';
    }
}

?>