Simple URL Slugging Function with Transliteration

slugify-with-transliteration-of-foreign-characters.php

<?php
/**
 * Slugifies a given string prepping it for usage as a URL string. Includes transliteration. Multi-byte ready for UTF-8.
 * @param str $str Original url
 * @param str $delimiter Separator to be used between words, default '-'
 * @param bool $strtolower Keep existing case or convert all to lower, default true
 * @return str Sluggified string;
 */
function slugify($str = '', $delimiter='-', $strtolower = true) {
	$str = convert_foreign_characters($str);

	$clean = preg_replace('/[^a-zA-Z0-9\/_|+ -]/', '', $clean);
	$clean = trim($clean, '-');

	if($strtolower) $clean = mb_strtolower($clean);

	$clean = preg_replace('/[\/_|+ -]+/', $delimiter, $clean);
	return $clean;
}


$translit_characters = array(

	// Aa
	'/Α|Ά|А|À|Á|Â|Ã|Ä|Å|Ǻ|Ā|Ă|Ą|Ǎ/' => 'A',
	'/α|ά|а|à|á|â|ã|å|ǻ|ā|ă|ą|ǎ|ª/' => 'a',

	// Bb
	'/Β|Б/' => 'B',
	'/β|б/' => 'b',

	// Cc
	'/Ç|Ć|Ĉ|Ċ|Č/' => 'C',
	'/ç|ć|ĉ|ċ|č/' => 'c',

	// Dd
	'/Δ|Д|Ð|Ď|Đ/' => 'D',
	'/δ|д|ð|ď|đ/' => 'd',

	// Ee
	'/Ε|Έ|Е|Э|Є|È|É|Ê|Ë|Ē|Ĕ|Ė|Ę|Ě/' => 'E',
	'/ε|έ|е|э|є|è|é|ê|ë|ē|ĕ|ė|ę|ě/' => 'e',

	// Ff
	'/Φ|Ф/' => 'F',
	'/φ|ф|ƒ/' => 'f',

	// Gg
	'/Γ|Г|Ĝ|Ğ|Ġ|Ģ/' => 'G',
	'/γ|г|ĝ|ğ|ġ|ģ/' => 'g',

	// Hh
	'/Х|Ĥ|Ħ/' => 'H',
	'/х|ĥ|ħ/' => 'h',

	// Ii
	'/Η|Ή|Ι|Ί|И|Ы|І|Ї|Ì|Í|Î|Ï|Ĩ|Ī|Ĭ|Ǐ|Į|İ/' => 'I',
	'/η|ή|ι|ί|и|ы|і|ї|ì|í|î|ï|ĩ|ī|ĭ|ǐ|į|ı/' => 'i',

	// Jj
	'/Ĵ/' => 'J',
	'/ĵ/' => 'j',

	// Kk
	'/Κ|К|Ķ/' => 'K',
	'/κ|к|ķ/' => 'k',

	// Ll
	'/Λ|Л|Ĺ|Ļ|Ľ|Ŀ|Ł/' => 'L',
	'/λ|л|ĺ|ļ|ľ|ŀ|ł/' => 'l',

	// Mm
	'/Μ|М/' => 'M',
	'/μ|м/' => 'm',

	// Nn
	'/Ν|Н|Ñ|Ń|Ņ|Ň/' => 'N',
	'/ν|н|ñ|ń|ņ|ň|ʼn/' => 'n',

	// Oo
	'/Ο|Ό|О|Ò|Ó|Ô|Õ|Ō|Ŏ|Ǒ|Ő|Ơ|Ø|Ǿ/' => 'O',
	'/ο|ό|о|ò|ó|ô|õ|ō|ŏ|ǒ|ő|ơ|ø|ǿ|º/' => 'o',

	// Pp
	'/Π|П/' => 'P',
	'/π|п/' => 'p',

	// Rr
	'/Ρ|Р|Ŕ|Ŗ|Ř/' => 'R',
	'/ρ|р|ŕ|ŗ|ř/' => 'r',

	// Ss
	'/Σ|С|Ś|Ŝ|Ş|Š/' => 'S',
	'/σ|ς|с|ś|ŝ|ş|š|ſ/' => 's',

	// Tt
	'/Τ|Т|Ţ|Ť|Ŧ/' => 'T',
	'/τ|т|ţ|ť|ŧ/' => 't',

	// Uu
	'/У|Ù|Ú|Û|Ũ|Ū|Ŭ|Ů|Ű|Ų|Ư|Ǔ|Ǖ|Ǘ|Ǚ|Ǜ/' => 'U',
	'/у|ù|ú|û|ũ|ū|ŭ|ů|ű|ų|ư|ǔ|ǖ|ǘ|ǚ|ǜ/' => 'u',

	// Vv
	'/В/' => 'V',
	'/в/' => 'v',

	// Ww
	'/Ω|Ώ|Ŵ/' => 'W',
	'/ω|ώ|ŵ/' => 'w',

	// Xx
	'/Χ/' => 'X',
	'/χ/' => 'x',

	// Yy
	'/Υ|Ύ|Ψ|Й|Ý|Ÿ|Ŷ/' => 'Y',
	'/υ|ύ|ψ|й|ý|ÿ|ŷ/' => 'y',

	// Zz
	'/Ζ|З|Ź|Ż|Ž/' => 'Z',
	'/ζ|з|ź|ż|ž/' => 'z',

	'/Θ/' => 'Th',
	'/θ/' => 'th',

	'/Ξ/' => 'Ks',
	'/ξ/' => 'ks',

	'/Ё/' => 'Yo',
	'/ё/' => 'yo',

	'/Ж/' => 'Zh',
	'/ж/' => 'zh',

	'/Ц/' => 'Ts',
	'/ц/' => 'ts',

	'/Ч/' => 'Ch',
	'/ч/' => 'ch',

	'/Ш/' => 'Sh',
	'/ш/' => 'sh',

	'/Щ/' => 'Sch',
	'/щ/' => 'sch',

	'/Ь|Ъ/' => '',
	'/ь|ъ/' => '',

	'/Ю/' => 'Yu',
	'/ю/' => 'yu',

	'/Я/' => 'Ya',
	'/я/' => 'ya',

	'/Æ|Ǽ/' => 'AE',
	'/Ä/' => 'Ae',
	'/ä|æ|ǽ/' => 'ae',

	'/Œ/' => 'OE',
	'/Ö/' => 'Oe',
	'/ö|œ/' => 'oe',

	'/Ü/' => 'Ue',
	'/ü/' => 'ue',

	'/IJ/' => 'IJ',
	'/ij/' => 'ij',

	'/ß/'=> 'ss',

);

/**
 * Transliterate foreign characters to their latin counterparts
 * @param str $str_i String to transliterate
 * @return str Transliterated string
 */
function convert_foreign_characters($str_i) {
	return @preg_replace(array_keys($translit_characters), array_values($translit_characters), $str_i);
}