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typo3conf/ext/vhs/Classes/ViewHelpers/Math/AverageViewHelper.php

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+<?php
+namespace FluidTYPO3\Vhs\ViewHelpers\Math;
+
+/*
+ * 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.
+ */
+
+/**
+ * Math: Average
+ *
+ * Performs average across an array. If $a is an array and
+ * $b is an array, each member of $a is averaged against the
+ * same member in $b. If $a is an array and $b is a number,
+ * each member of $a is averaged agained $b. If $a is an array
+ * this array is averaged to one number. If $a is a number and
+ * $b is not provided or NULL, $a is gracefully returned as an
+ * average value of itself.
+ *
+ * @author Claus Due <claus@namelesscoder.net>
+ * @package Vhs
+ * @subpackage ViewHelpers\Math
+ */
+class AverageViewHelper extends AbstractMultipleMathViewHelper {
+
+	/**
+	 * @return void
+	 */
+	public function initializeArguments() {
+		parent::initializeArguments();
+		$this->overrideArgument('b', 'mixed', 'Optional: Second number or Iterator/Traversable/Array for calculation', FALSE, NULL);
+	}
+
+	/**
+	 * @return mixed
+	 * @throw Exception
+	 */
+	public function render() {
+		$a = $this->getInlineArgument();
+		$b = $this->arguments['b'];
+		$aIsIterable = $this->assertIsArrayOrIterator($a);
+		$bIsIterable = $this->assertIsArrayOrIterator($b);
+		if (TRUE === $aIsIterable && NULL === $b) {
+			$a = $this->arrayFromArrayOrTraversableOrCSV($a);
+			$sum = array_sum($a);
+			$distribution = count($a);
+			return $sum / $distribution;
+		} elseif (TRUE === $aIsIterable && FALSE === $bIsIterable) {
+			$a = $this->arrayFromArrayOrTraversableOrCSV($a);
+			foreach ($a as $index => $value) {
+				$a[$index] = $this->calculateAction($value, $b);
+			}
+			return $a;
+		} elseif (TRUE === isset($a) && NULL === $b) {
+			return $a;
+		}
+		return $this->calculate($a, $b);
+	}
+
+	/**
+	 * @param mixed $a
+	 * @param $b
+	 * @return mixed
+	 */
+	protected function calculateAction($a, $b) {
+		return ($a + $b) / 2;
+	}
+
+}