From 1e0aa82a5d130b75fb8230c2fdc44719c79964d0 Mon Sep 17 00:00:00 2001
From: Hannes Papenberg <info@joomlager.de>
Date: Mon, 24 Apr 2023 14:14:12 +0200
Subject: [PATCH] Adding OutputFilter::stringJSSafe()

---
 Tests/OutputFilterTest.php | 12 ++++++++++++
 src/OutputFilter.php       | 31 +++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/Tests/OutputFilterTest.php b/Tests/OutputFilterTest.php
index 24bdd39d..de82aaf7 100644
--- a/Tests/OutputFilterTest.php
+++ b/Tests/OutputFilterTest.php
@@ -101,6 +101,18 @@ public function testLinkXhtmlSafe()
 		);
 	}
 
+	/**
+	 * Tests making strings safe for usage in JS
+	 */
+	public function testStringJSSafe()
+	{
+		$this->assertEquals(
+			'\u0054\u0065\u0073\u0074\u0020\u0073\u0074\u0072\u0069\u006e\u0067\u0020\u0045\u0073\u0070\u0061\u00f1\u006f\u006c\u0020\u0420\u0443\u0441\u0441\u043a\u0438\u0439\u0020\ud55c\uad6d\uc5b4\u0020\u{1f910}',
+			$this->object->stringJSSafe('Test string Español Русский 한국어 🤐'),
+			'Should convert the string to unicode escaped string'
+		);
+	}
+
 	/**
 	 * Tests filtering strings down to ASCII-7 lowercase URL text
 	 */
diff --git a/src/OutputFilter.php b/src/OutputFilter.php
index 865285d4..c22b8a05 100644
--- a/src/OutputFilter.php
+++ b/src/OutputFilter.php
@@ -89,6 +89,37 @@ function ($m)
 		);
 	}
 
+	/**
+	 * Processes a string and escapes it for use in JavaScript
+	 *
+	 * @param   string  $string  String to process
+	 *
+	 * @return  string  Processed text
+	 *
+	 * @since   3.0
+	 */
+	public static function stringJSSafe($string)
+	{
+		$chars   = preg_split('//u', $string, -1, PREG_SPLIT_NO_EMPTY);
+		$newStr = '';
+
+		foreach ($chars as $chr)
+		{
+			$code = str_pad(dechex(StringHelper::ord($chr)), 4, '0', STR_PAD_LEFT);
+
+			if (strlen($code) < 5)
+			{
+				$newStr .= '\\u' . $code;
+			}
+			else
+			{
+				$newStr .= '\\u{' . $code . '}';
+			}
+		}
+
+		return $newStr;
+	}
+
 	/**
 	 * Generates a URL safe version of the specified string with language transliteration.
 	 *