MediaWiki 1.30.2

[autoinstallsdev/mediawiki.git] / resources / src / jquery / jquery.byteLength.js

diff --git a/resources/src/jquery/jquery.byteLength.js b/resources/src/jquery/jquery.byteLength.js
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+/**
+ * @class jQuery.plugin.byteLength
+ * @author Jan Paul Posma, 2011
+ * @author Timo Tijhof, 2012
+ * @author David Chan, 2013
+ */
+
+/**
+ * Calculate the byte length of a string (accounting for UTF-8).
+ *
+ * @static
+ * @inheritable
+ * @param {string} str
+ * @return {number}
+ */
+jQuery.byteLength = function ( str ) {
+       // This basically figures out how many bytes a UTF-16 string (which is what js sees)
+       // will take in UTF-8 by replacing a 2 byte character with 2 *'s, etc, and counting that.
+       // Note, surrogate (\uD800-\uDFFF) characters are counted as 2 bytes, since there's two of them
+       // and the actual character takes 4 bytes in UTF-8 (2*2=4). Might not work perfectly in
+       // edge cases such as illegal sequences, but that should never happen.
+
+       // https://en.wikipedia.org/wiki/UTF-8#Description
+       // The mapping from UTF-16 code units to UTF-8 bytes is as follows:
+       // > Range 0000-007F: codepoints that become 1 byte of UTF-8
+       // > Range 0080-07FF: codepoints that become 2 bytes of UTF-8
+       // > Range 0800-D7FF: codepoints that become 3 bytes of UTF-8
+       // > Range D800-DFFF: Surrogates (each pair becomes 4 bytes of UTF-8)
+       // > Range E000-FFFF: codepoints that become 3 bytes of UTF-8 (continued)
+
+       return str
+               .replace( /[\u0080-\u07FF\uD800-\uDFFF]/g, '**' )
+               .replace( /[\u0800-\uD7FF\uE000-\uFFFF]/g, '***' )
+               .length;
+};
+
+/**
+ * @class jQuery
+ * @mixins jQuery.plugin.byteLength
+ */