/app/models/behaviors/sluggable.php

<?php
class SluggableBehavior extends ModelBehavior {
	/**
	 * Translation table
	 *
	 * @var array
	 */
	public $translations = array();

	/**
	 * Constructor
	 */
	public function __construct() {
		parent::__construct();
		if (empty($this->translations)) {
			$this->translations = array(
				'iso-8859-1' => array(
					chr(128).chr(131).chr(138).chr(142).chr(154).chr(158)
					.chr(159).chr(162).chr(165).chr(181).chr(192).chr(193).chr(194)
					.chr(195).chr(196).chr(197).chr(199).chr(200).chr(201).chr(202)
					.chr(203).chr(204).chr(205).chr(206).chr(207).chr(209).chr(210)
					.chr(211).chr(212).chr(213).chr(214).chr(216).chr(217).chr(218)
					.chr(219).chr(220).chr(221).chr(224).chr(225).chr(226).chr(227)
					.chr(228).chr(229).chr(231).chr(232).chr(233).chr(234).chr(235)
					.chr(236).chr(237).chr(238).chr(239).chr(241).chr(242).chr(243)
					.chr(244).chr(245).chr(246).chr(248).chr(249).chr(250).chr(251)
					.chr(252).chr(253).chr(255),
					'EfSZsz' . 'YcYuAAA' . 'AAACEEE' . 'EIIIINO' . 'OOOOOUU' . 'UUYaaaa' . 'aaceeee' . 'iiiinoo' . 'oooouuu' . 'uyy',
					array(chr(140), chr(156), chr(198), chr(208), chr(222), chr(223), chr(230), chr(240), chr(254)),
					array('OE', 'oe', 'AE', 'DH', 'TH', 'ss', 'ae', 'dh', 'th')
				),
				'utf-8' => array(
					array(
						// Decompositions for Latin-1 Supplement
						chr(195).chr(128) => 'A', chr(195).chr(129) => 'A',
						chr(195).chr(130) => 'A', chr(195).chr(131) => 'A',
						chr(195).chr(132) => 'A', chr(195).chr(133) => 'A',
						chr(195).chr(135) => 'C', chr(195).chr(136) => 'E',
						chr(195).chr(137) => 'E', chr(195).chr(138) => 'E',
						chr(195).chr(139) => 'E', chr(195).chr(140) => 'I',
						chr(195).chr(141) => 'I', chr(195).chr(142) => 'I',
						chr(195).chr(143) => 'I', chr(195).chr(145) => 'N',
						chr(195).chr(146) => 'O', chr(195).chr(147) => 'O',
						chr(195).chr(148) => 'O', chr(195).chr(149) => 'O',
						chr(195).chr(150) => 'O', chr(195).chr(153) => 'U',
						chr(195).chr(154) => 'U', chr(195).chr(155) => 'U',
						chr(195).chr(156) => 'U', chr(195).chr(157) => 'Y',
						chr(195).chr(159) => 's', chr(195).chr(160) => 'a',
						chr(195).chr(161) => 'a', chr(195).chr(162) => 'a',
						chr(195).chr(163) => 'a', chr(195).chr(164) => 'a',
						chr(195).chr(165) => 'a', chr(195).chr(167) => 'c',
						chr(195).chr(168) => 'e', chr(195).chr(169) => 'e',
						chr(195).chr(170) => 'e', chr(195).chr(171) => 'e',
						chr(195).chr(172) => 'i', chr(195).chr(173) => 'i',
						chr(195).chr(174) => 'i', chr(195).chr(175) => 'i',
						chr(195).chr(177) => 'n', chr(195).chr(178) => 'o',
						chr(195).chr(179) => 'o', chr(195).chr(180) => 'o',
						chr(195).chr(181) => 'o', chr(195).chr(182) => 'o',
						chr(195).chr(182) => 'o', chr(195).chr(185) => 'u',
						chr(195).chr(186) => 'u', chr(195).chr(187) => 'u',
						chr(195).chr(188) => 'u', chr(195).chr(189) => 'y',
						chr(195).chr(191) => 'y',
						// Decompositions for Latin Extended-A
						chr(196).chr(128) => 'A', chr(196).chr(129) => 'a',
						chr(196).chr(130) => 'A', chr(196).chr(131) => 'a',
						chr(196).chr(132) => 'A', chr(196).chr(133) => 'a',
						chr(196).chr(134) => 'C', chr(196).chr(135) => 'c',
						chr(196).chr(136) => 'C', chr(196).chr(137) => 'c',
						chr(196).chr(138) => 'C', chr(196).chr(139) => 'c',
						chr(196).chr(140) => 'C', chr(196).chr(141) => 'c',
						chr(196).chr(142) => 'D', chr(196).chr(143) => 'd',
						chr(196).chr(144) => 'D', chr(196).chr(145) => 'd',
						chr(196).chr(146) => 'E', chr(196).chr(147) => 'e',
						chr(196).chr(148) => 'E', chr(196).chr(149) => 'e',
						chr(196).chr(150) => 'E', chr(196).chr(151) => 'e',
						chr(196).chr(152) => 'E', chr(196).chr(153) => 'e',
						chr(196).chr(154) => 'E', chr(196).chr(155) => 'e',
						chr(196).chr(156) => 'G', chr(196).chr(157) => 'g',
						chr(196).chr(158) => 'G', chr(196).chr(159) => 'g',
						chr(196).chr(160) => 'G', chr(196).chr(161) => 'g',
						chr(196).chr(162) => 'G', chr(196).chr(163) => 'g',
						chr(196).chr(164) => 'H', chr(196).chr(165) => 'h',
						chr(196).chr(166) => 'H', chr(196).chr(167) => 'h',
						chr(196).chr(168) => 'I', chr(196).chr(169) => 'i',
						chr(196).chr(170) => 'I', chr(196).chr(171) => 'i',
						chr(196).chr(172) => 'I', chr(196).chr(173) => 'i',
						chr(196).chr(174) => 'I', chr(196).chr(175) => 'i',
						chr(196).chr(176) => 'I', chr(196).chr(177) => 'i',
						chr(196).chr(178) => 'IJ',chr(196).chr(179) => 'ij',
						chr(196).chr(180) => 'J', chr(196).chr(181) => 'j',
						chr(196).chr(182) => 'K', chr(196).chr(183) => 'k',
						chr(196).chr(184) => 'k', chr(196).chr(185) => 'L',
						chr(196).chr(186) => 'l', chr(196).chr(187) => 'L',
						chr(196).chr(188) => 'l', chr(196).chr(189) => 'L',
						chr(196).chr(190) => 'l', chr(196).chr(191) => 'L',
						chr(197).chr(128) => 'l', chr(197).chr(129) => 'L',
						chr(197).chr(130) => 'l', chr(197).chr(131) => 'N',
						chr(197).chr(132) => 'n', chr(197).chr(133) => 'N',
						chr(197).chr(134) => 'n', chr(197).chr(135) => 'N',
						chr(197).chr(136) => 'n', chr(197).chr(137) => 'N',
						chr(197).chr(138) => 'n', chr(197).chr(139) => 'N',
						chr(197).chr(140) => 'O', chr(197).chr(141) => 'o',
						chr(197).chr(142) => 'O', chr(197).chr(143) => 'o',
						chr(197).chr(144) => 'O', chr(197).chr(145) => 'o',
						chr(197).chr(146) => 'OE',chr(197).chr(147) => 'oe',
						chr(197).chr(148) => 'R',chr(197).chr(149) => 'r',
						chr(197).chr(150) => 'R',chr(197).chr(151) => 'r',
						chr(197).chr(152) => 'R',chr(197).chr(153) => 'r',
						chr(197).chr(154) => 'S',chr(197).chr(155) => 's',
						chr(197).chr(156) => 'S',chr(197).chr(157) => 's',
						chr(197).chr(158) => 'S',chr(197).chr(159) => 's',
						chr(197).chr(160) => 'S', chr(197).chr(161) => 's',
						chr(197).chr(162) => 'T', chr(197).chr(163) => 't',
						chr(197).chr(164) => 'T', chr(197).chr(165) => 't',
						chr(197).chr(166) => 'T', chr(197).chr(167) => 't',
						chr(197).chr(168) => 'U', chr(197).chr(169) => 'u',
						chr(197).chr(170) => 'U', chr(197).chr(171) => 'u',
						chr(197).chr(172) => 'U', chr(197).chr(173) => 'u',
						chr(197).chr(174) => 'U', chr(197).chr(175) => 'u',
						chr(197).chr(176) => 'U', chr(197).chr(177) => 'u',
						chr(197).chr(178) => 'U', chr(197).chr(179) => 'u',
						chr(197).chr(180) => 'W', chr(197).chr(181) => 'w',
						chr(197).chr(182) => 'Y', chr(197).chr(183) => 'y',
						chr(197).chr(184) => 'Y', chr(197).chr(185) => 'Z',
						chr(197).chr(186) => 'z', chr(197).chr(187) => 'Z',
						chr(197).chr(188) => 'z', chr(197).chr(189) => 'Z',
						chr(197).chr(190) => 'z', chr(197).chr(191) => 's',
						// Russian symbols (ISO 9-95)
						chr(208).chr(129) => 'YO',
						chr(208).chr(132) => 'E',
						chr(208).chr(134) => 'I',
						chr(208).chr(135) => 'YI',
						chr(208).chr(144) => 'A',
						chr(208).chr(145) => 'B',
						chr(208).chr(146) => 'V',
						chr(208).chr(147) => 'G',
						chr(208).chr(148) => 'D',
						chr(208).chr(149) => 'E',
						chr(208).chr(150) => 'ZH',
						chr(208).chr(151) => 'Z',
						chr(208).chr(152) => 'I',
						chr(208).chr(153) => 'Y',
						chr(208).chr(154) => 'K',
						chr(208).chr(155) => 'L',
						chr(208).chr(156) => 'M',
						chr(208).chr(157) => 'N',
						chr(208).chr(158) => 'O',
						chr(208).chr(159) => 'P',
						chr(208).chr(160) => 'R',
						chr(208).chr(161) => 'S',
						chr(208).chr(162) => 'T',
						chr(208).chr(163) => 'U',
						chr(208).chr(164) => 'F',
						chr(208).chr(165) => 'H',
						chr(208).chr(166) => 'TS',
						chr(208).chr(167) => 'CH',
						chr(208).chr(168) => 'SH',
						chr(208).chr(169) => 'SCH',
						chr(208).chr(171) => 'YI',
						chr(208).chr(173) => 'E',
						chr(208).chr(174) => 'YU',
						chr(208).chr(175) => 'YA',
						chr(208).chr(176) => 'a',
						chr(208).chr(177) => 'b',
						chr(208).chr(178) => 'v',
						chr(208).chr(179) => 'g',
						chr(208).chr(180) => 'd',
						chr(208).chr(181) => 'e',
						chr(208).chr(182) => 'zh',
						chr(208).chr(183) => 'z',
						chr(208).chr(184) => 'i',
						chr(208).chr(185) => 'y',
						chr(208).chr(186) => 'k',
						chr(208).chr(187) => 'l',
						chr(208).chr(188) => 'm',
						chr(208).chr(189) => 'n',
						chr(208).chr(190) => 'o',
						chr(208).chr(191) => 'p',
						chr(209).chr(128) => 'r',
						chr(209).chr(129) => 's',
						chr(209).chr(130) => 't',
						chr(209).chr(131) => 'u',
						chr(209).chr(132) => 'f',
						chr(209).chr(133) => 'h',
						chr(209).chr(134) => 'ts',
						chr(209).chr(135) => 'ch',
						chr(209).chr(136) => 'sh',
						chr(209).chr(137) => 'sch',
						chr(209).chr(139) => 'yi',
						chr(209).chr(141) => 'e',
						chr(209).chr(142) => 'yu',
						chr(209).chr(143) => 'ya',
						chr(209).chr(145) => 'yo',
						chr(209).chr(148) => 'e',
						chr(209).chr(150) => 'i',
						chr(209).chr(151) => 'yi',
						chr(210).chr(144) => 'G',
						chr(210).chr(145) => 'g',
						// Euro Sign
						chr(226).chr(130).chr(172) => 'E'
					)
				)
			);
		}
	}

	/**
	 * Initiate behavior for the model using specified settings. Available settings:
	 *
	 * - label: 	(array | string, optional) set to the field name that contains the
	 * 				string from where to generate the slug, or a set of field names to
	 * 				concatenate for generating the slug. DEFAULTS TO: title
	 *
	 * - real:		(boolean, optional) if set to true then field names defined in
	 * 				label must exist in the database table. DEFAULTS TO: true
	 *
	 * - slug:		(string, optional) name of the field name that holds generated slugs.
	 * 				DEFAULTS TO: slug
	 *
	 * - separator:	(string, optional) separator character / string to use for replacing
	 * 				non alphabetic characters in generated slug. DEFAULTS TO: -
	 *
	 * - length:	(integer, optional) maximum length the generated slug can have.
	 * 				DEFAULTS TO: 100
	 *
	 * - overwrite: (boolean, optional) set to true if slugs should be re-generated when
	 * 				updating an existing record. DEFAULTS TO: false
	 *
	 * - ignore:    (array, optional) array of words that should not be part of a slug.
	 *
	 * @param object $model Model using the behaviour
	 * @param array $settings Settings to override for model.
	 */
	public function setup($model, $settings = array()) {
		$default = array(
			'real' => true,
			'label' => array('title'),
			'slug' => 'slug',
			'separator' => '-',
			'length' => 100,
			'overwrite' => false,
			'translation' => null,
			'ignore' => array(
				'and', 'for', 'is', 'of', 'the'
			)
		);

		if (!isset($this->settings[$model->alias])) {
			$configured = Configure::read('Sluggable');
			if (!empty($configured)) {
				if (!empty($configured['translations'])) {
					$this->translations = Set::merge($this->translations, $configured['translations']);
					unset($configured['translations']);
				}
				foreach($default as $key => $value) {
					if (isset($configured[$key])) {
						$default[$key] = $configured[$key];
					}
				}
			}
			$this->settings[$model->alias] = $default;
		}

		$this->settings[$model->alias] = array_merge($this->settings[$model->alias], $settings);
	}

	/**
	 * Run before a model is saved, used to set up slug for model.
	 *
	 * @param object $model Model about to be saved.
	 * @return boolean true if save should proceed, false otherwise
	 */
	public function beforeSave($model) {
		$return = parent::beforeSave($model);
		$settings = $this->settings[$model->alias];
		$fields = (array) $settings['label'];

		if ($settings['real']) {
			foreach($fields as $field) {
				if (!$model->hasField($field)) {
					return $return;
				}
			}
		}

		if ((!$settings['real'] || $model->hasField($settings['slug'])) && ($settings['overwrite'] || empty($model->id))) {
			$label = '';

			foreach($fields as $field) {
				if (!empty($model->data[$model->alias][$field])) {
					$label .= (!empty($label) ? ' ' : '') . $model->data[$model->alias][$field];
				}
			}

			if (!empty($label)) {
				$slug = $this->_slug($label, $settings);
				$conditions = array($model->alias . '.' . $settings['slug'] => $slug);
				if (!empty($model->id)) {
					$conditions['not'] = array($model->alias . '.' . $model->primaryKey => $model->id);
				}

				$result = $model->find('all', array(
					'conditions' => $conditions,
					'fields' => array($model->primaryKey, $settings['slug']),
					'recursive' => -1
				));

				$sameUrls = null;
				if (!empty($result)) {
					$sameUrls = Set::extract($result, '/' . $model->alias . '/' . $settings['slug']);
				}

				if (!empty($sameUrls)) {
					$begginingSlug = $slug;
					$index = 1;
					do {
						$currentSlug = $begginingSlug . $settings['separator'] . $index++;
						if (!in_array($currentSlug, $sameUrls)) {
							$slug = $currentSlug;
							break;
						}
					} while(true);
				}

				$model->data[$model->alias][$settings['slug']] = $slug;
				$this->_addToWhitelist($model, $settings['slug']);
			}
		}

		return $return;
	}

	/**
	 * Generate a slug for the given string using specified settings.
	 *
	 * @param string $string String from where to generate slug
	 * @param array $settings Settings to use (looks for 'separator' and 'length')
	 * @return string Slug for given string
	 */
	protected function _slug($string, $settings) {
		if (!empty($settings['ignore'])) {
			$words = array();
			foreach((array) $settings['ignore'] as $word) {
				$words[] = preg_quote($word);
			}
			$newString = preg_replace('/\b(\s*)(' . implode('|', $words) . ')(\s*)\b/i', '\\1\\3', $string);
			if (!empty($newString)) {
				$string = $newString;
			}
		}
		if (!empty($settings['translation']) && is_array($settings['translation'])) {
			if (count($settings['translation']) >= 2 && count($settings['translation']) % 2 == 0) {
				for($i=0, $limiti=count($settings['translation']); $i < $limiti; $i += 2) {
					$from = $settings['translation'][$i];
					$to = $settings['translation'][$i + 1];

					if (is_string($from) && is_string($to)) {
						$string = strtr($string, $from, $to);
					} else {
						$string = str_replace($from, $to, $string);
					}
				}
			} else if (count($settings['translation']) == 1) {
				$string = strtr($string, $settings['translation'][0]);
			}

			$string = strtolower($string);
		} else if (
			!empty($settings['translation']) && is_string($settings['translation']) &&
			in_array(strtolower($settings['translation']), array_keys($this->translations))
		) {
			return $this->_slug(
				$string,
				array_merge($settings, array('translation' => $this->translations[$settings['translation']]))
			);
		}

		$string = strtolower($string);
		$string = preg_replace('/[^a-z0-9_]/i', $settings['separator'], $string);
		$string = preg_replace(
			'/' . preg_quote($settings['separator']) . '[' . preg_quote($settings['separator']) . ']*/',
			$settings['separator'],
			$string
		);

		if (strlen($string) > $settings['length']) {
			$string = substr($string, 0, $settings['length']);
		}

		$string = preg_replace('/' . preg_quote($settings['separator']) . '$/', '', $string);
		$string = preg_replace('/^' . preg_quote($settings['separator']) . '/', '', $string);

		return $string;
	}
}

?>