gistfile1.php

<?php

/**
 * Copyright 2007-2010, Cake Development Corporation (http://cakedc.com)
 *
 * Licensed under The MIT License
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright Copyright 2007-2010, Cake Development Corporation (http://cakedc.com)
 * @license MIT License (http://www.opensource.org/licenses/mit-license.php)
 */

/**
 * Utils Plugin
 *
 * Utils Tiny Sluggable Behavior
 *
 * @package utils
 * @subpackage utils.models.behaviors
 */
class TinySluggableBehavior extends ModelBehavior {

      /**
       * Settings to configure the behavior
       *
       * @var array
       */
      public $settings = array();
      /**
       * Default settings
       *
       * @var array
       */
      protected $_defaults = array(
          'tinySlug' => 'tiny_slug',
          'codeset' => '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',
          'order' => 'created'
      );

      /**
       * Initiate behavior - The Model must have a field for the tiny_slug along with a "created" field
       *
       * @param object $Model
       * @param array $settings Settings for the behavior. Keys: 
       * 	- tinySlug: name of the tiny slug field in the table [default: tiny_slug]
       *  - codeset: valid characters for tiny slug [default: 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ]
       */
      public function setup(&$Model, $settings = array()) {
            $this->settings[$Model->alias] = array_merge($this->_defaults, $settings);
            $Model->tinySlug = $this->settings[$Model->alias]['tinySlug'];
            $this->settings[$Model->alias]['base'] = strlen($this->settings[$Model->alias]['codeset']);
      }

      /**
       * beforeSave callback
       *
       * @param object $Model
       */
      public function beforeSave(&$Model) {
            if (empty($Model->data[$Model->alias])) {
                  return;
            }

            if (empty($Model->data[$Model->alias][$Model->tinySlug])) {
                  $Model->data[$Model->alias][$Model->tinySlug] = $this->__getNextSlug($Model);
            }
            return true;
      }

      /**
       * Calculates the next available slug and returns it
       *
       * @return string next avalible tiny slug
       */
      private function __getNextSlug(&$Model) {
            $new = '';
            $prev = $Model->find('first', array(
                        'contain' => array(),
                        'fields' => array("{$Model->alias}.{$Model->tinySlug}", "{$Model->alias}." . $this->settings[$Model->alias]['order']),
                        'order' => "{$Model->alias}.{$this->settings[$Model->alias]['order']} DESC"));

            if (empty($prev)) {
                  $new = $this->settings[$Model->alias]['codeset'][0];
            } else {
                  $new = $this->__toShort($Model, (string) $this->__toDecimal($Model, $prev[$Model->alias][$Model->tinySlug]) + 1);
                  $attempts = 0;
                  $maxAttempts = 5; // Overriden after the first attempt
                  $new = $prev[$Model->alias][$Model->tinySlug];

                  // Check if this slug does not already exists
                  do {
                        if ($attempts == 1) {
                              $maxAttempts = $Model->find('count', array(
                                          'conditions' => array(
                                              $Model->alias . '.' . $this->settings[$Model->alias]['order'] => $prev[$Model->alias][$this->settings[$Model->alias]['order']])));
                        }
                        $new = $this->__toShort($Model, $this->__toDecimal($Model, $new) + 1);
                        $existing = $Model->find('count', array(
                                    'conditions' => array(
                                        $Model->alias . '.' . $Model->tinySlug => $new)));
                        $attempts++;
                  } while (!empty($existing) && $attempts < $maxAttempts);
            }
            return $new;
      }

      /**
       * Calculates the
       *
       * @param int $decimal the decimal to convert
       * @return string
       */
      private function __toShort(&$Model, $decimal) {
            $codeSet = $this->settings[$Model->alias]['codeset'];
            $base = $this->settings[$Model->alias]['base'];
            $short = '';
            while ($decimal > 0) {
                  $short = substr($codeSet, ($decimal % $base), 1) . $short;
                  $decimal = floor($decimal / $base);
            }
            return $short;
      }

      /**
       * Converts a tiny slug into an integer
       *
       * @param string $short
       * @return integer
       */
      private function __toDecimal(&$Model, $short) {
            $codeSet = $this->settings[$Model->alias]['codeset'];
            $base = $this->settings[$Model->alias]['base'];
            $decimal = 0;
            for ($i = strlen($short); $i; $i--) {
                  $decimal += strpos($codeSet, substr($short, (-1 * ( $i - strlen($short) )), 1)) * pow($base, $i - 1);
            }
            return $decimal;
      }

}