:octocat: QRMarkup: extract CssColorModuleValueTrait to allow use in other output classes

src/Output/CssColorModuleValueTrait.php

@@ -0,0 +1,74 @@
+<?php
+/**
+ * CssColorModuleValueTrait.php
+ *
+ * @created      04.05.2024
+ * @author       smiley <smiley@chillerlan.net>
+ * @copyright    2024 smiley
+ * @license      MIT
+ */
+
+namespace chillerlan\QRCode\Output;
+
+use function is_string, preg_match, strip_tags, trim;
+
+/**
+ * Module value checks for output classes that use CSS colors
+ */
+trait CssColorModuleValueTrait{
+
+	/**
+	 * note: we're not necessarily validating the several values, just checking the general syntax
+	 * note: css4 colors are not included
+	 *
+	 * @todo: XSS proof
+	 *
+	 * @see https://developer.mozilla.org/en-US/docs/Web/CSS/color_value
+	 * @implements \chillerlan\QRCode\Output\QROutputInterface::moduleValueIsValid()
+	 * @inheritDoc
+	 */
+	public static function moduleValueIsValid(mixed $value):bool{
+
+		if(!is_string($value)){
+			return false;
+		}
+
+		$value = trim(strip_tags($value), " '\"\r\n\t");
+
+		// hex notation
+		// #rgb(a)
+		// #rrggbb(aa)
+		if(preg_match('/^#([\da-f]{3}){1,2}$|^#([\da-f]{4}){1,2}$/i', $value)){
+			return true;
+		}
+
+		// css: hsla/rgba(...values)
+		if(preg_match('#^(hsla?|rgba?)\([\d .,%/]+\)$#i', $value)){
+			return true;
+		}
+
+		// predefined css color
+		if(preg_match('/^[a-z]+$/i', $value)){
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	 * @implements \chillerlan\QRCode\Output\QROutputAbstract::prepareModuleValue()
+	 * @inheritDoc
+	 */
+	protected function prepareModuleValue(mixed $value):string{
+		return trim(strip_tags($value), " '\"\r\n\t");
+	}
+
+	/**
+	 * @implements \chillerlan\QRCode\Output\QROutputAbstract::getDefaultModuleValue()
+	 * @inheritDoc
+	 */
+	protected function getDefaultModuleValue(bool $isDark):string{
+		return ($isDark) ? '#000' : '#fff';
+	}
+
+}