AbstractConditionViewHelper.php

Go to the documentation of this file.

<?php
namespace TYPO3\CMS\Fluid\Core\ViewHelper;

/*                                                                        *
 * This script is backported from the TYPO3 Flow package "TYPO3.Fluid".   *
 *                                                                        *
 * It is free software; you can redistribute it and/or modify it under    *
 * the terms of the GNU Lesser General Public License, either version 3   *
 *  of the License, or (at your option) any later version.                *
 *                                                                        *
 * The TYPO3 project - inspiring people to share!                         *
 *                                                                        */

use TYPO3\CMS\Fluid\ViewHelpers\ThenViewHelper;
use TYPO3\CMS\Fluid\ViewHelpers\ElseViewHelper;
use TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\ViewHelperNode;

abstract class AbstractConditionViewHelper extends \TYPO3\CMS\Fluid\Core\ViewHelper\AbstractViewHelper implements \TYPO3\CMS\Fluid\Core\ViewHelper\Facets\ChildNodeAccessInterface, \TYPO3\CMS\Fluid\Core\ViewHelper\Facets\CompilableInterface
{
    private $childNodes = array();

    public function setChildNodes(array $childNodes)
    {
        $this->childNodes = $childNodes;
    }

    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);
    }

    public function render()
    {
        if (static::evaluateCondition($this->arguments)) {
            return $this->renderThenChild();
        } else {
            return $this->renderElseChild();
        }
    }

    protected function renderThenChild()
    {
        $hasEvaluated = true;
        $result = static::renderStaticThenChild($this->arguments, $hasEvaluated);
        if ($hasEvaluated) {
            return $result;
        }

        $elseViewHelperEncountered = false;
        foreach ($this->childNodes as $childNode) {
            if ($childNode instanceof ViewHelperNode
                && $childNode->getViewHelperClassName() === ThenViewHelper::class) {
                $data = $childNode->evaluate($this->renderingContext);
                return $data;
            }
            if ($childNode instanceof ViewHelperNode
                && $childNode->getViewHelperClassName() === ElseViewHelper::class) {
                $elseViewHelperEncountered = true;
            }
        }

        if ($elseViewHelperEncountered) {
            return '';
        } else {
            return $this->renderChildren();
        }
    }

    protected static function renderStaticThenChild($arguments, &$hasEvaluated)
    {
        if (isset($arguments['then'])) {
            return $arguments['then'];
        }
        if (isset($arguments['__thenClosure'])) {
            $thenClosure = $arguments['__thenClosure'];
            return $thenClosure();
        } elseif (isset($arguments['__elseClosure'])) {
            return '';
        }

        $hasEvaluated = false;
    }

    protected function renderElseChild()
    {
        $hasEvaluated = true;
        $result = static::renderStaticElseChild($this->arguments, $hasEvaluated);
        if ($hasEvaluated) {
            return $result;
        }

        foreach ($this->childNodes as $childNode) {
            if ($childNode instanceof ViewHelperNode
                && $childNode->getViewHelperClassName() === ElseViewHelper::class) {
                return $childNode->evaluate($this->renderingContext);
            }
        }

        return '';
    }


    protected static function renderStaticElseChild($arguments, &$hasEvaluated)
    {
        if (isset($arguments['else'])) {
            return $arguments['else'];
        }
        if (isset($arguments['__elseClosure'])) {
            $elseClosure = $arguments['__elseClosure'];
            return $elseClosure();
        }

        $hasEvaluated = false;
    }

    public function compile($argumentsVariableName, $renderChildrenClosureVariableName, &$initializationPhpCode, \TYPO3\CMS\Fluid\Core\Parser\SyntaxTree\AbstractNode $syntaxTreeNode, \TYPO3\CMS\Fluid\Core\Compiler\TemplateCompiler $templateCompiler)
    {
        foreach ($syntaxTreeNode->getChildNodes() as $childNode) {
            if ($childNode instanceof ViewHelperNode
                && $childNode->getViewHelperClassName() === ThenViewHelper::class) {
                $childNodesAsClosure = $templateCompiler->wrapChildNodesInClosure($childNode);
                $initializationPhpCode .= sprintf('%s[\'__thenClosure\'] = %s;', $argumentsVariableName, $childNodesAsClosure) . LF;
            }
            if ($childNode instanceof ViewHelperNode
                && $childNode->getViewHelperClassName() === ElseViewHelper::class) {
                $childNodesAsClosure = $templateCompiler->wrapChildNodesInClosure($childNode);
                $initializationPhpCode .= sprintf('%s[\'__elseClosure\'] = %s;', $argumentsVariableName, $childNodesAsClosure) . LF;
            }
        }

        return sprintf('%s::renderStatic(%s, %s, $renderingContext)',
            get_class($this), $argumentsVariableName, $renderChildrenClosureVariableName);
    }

    public static function renderStatic(array $arguments, \Closure $renderChildrenClosure, \TYPO3\CMS\Fluid\Core\Rendering\RenderingContextInterface $renderingContext)
    {
        $hasEvaluated = true;
        if (static::evaluateCondition($arguments)) {
            $result = static::renderStaticThenChild($arguments, $hasEvaluated);
            if ($hasEvaluated) {
                return $result;
            }

            return $renderChildrenClosure();
        } else {
            $result = static::renderStaticElseChild($arguments, $hasEvaluated);
            if ($hasEvaluated) {
                return $result;
            }
        }

        return '';
    }

    protected static function evaluateCondition($arguments = null)
    {
        return (isset($arguments['condition']) && $arguments['condition']);
    }
}