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   1  <?php
   2  
   3  /**
   4   * sfChoiceFormat class file.
   5   *
   6   * This program is free software; you can redistribute it and/or modify
   7   * it under the terms of the BSD License.
   8   *
   9   * Copyright(c) 2004 by Qiang Xue. All rights reserved.
  10   *
  11   * To contact the author write to {@link mailto:qiang.xue@gmail.com Qiang Xue}
  12   * The latest version of PRADO can be obtained from:
  13   * {@link http://prado.sourceforge.net/}
  14   *
  15   * @author     Wei Zhuo <weizhuo[at]gmail[dot]com>
  16   * @version    $Id: sfChoiceFormat.class.php 3148 2007-01-04 19:34:28Z fabien $
  17   * @package    symfony
  18   * @subpackage i18n
  19   */
  20  
  21  
  22  /**
  23   * sfChoiceFormat class.
  24   * 
  25   * sfChoiceFormat converts between ranges of numeric values and string 
  26   * names for those ranges.
  27   *
  28   * A sfChoiceFormat splits the real number line -Inf to +Inf into two or 
  29   * more contiguous ranges. Each range is mapped to a string. 
  30   * sfChoiceFormat is generally used in a MessageFormat for displaying 
  31   * grammatically correct plurals such as "There are 2 files."
  32   *
  33   * <code>
  34   *  $string = '[0] are no files |[1] is one file |(1,Inf] are {number} files';
  35   *  
  36   *  $formatter = new sfMessageFormat(...); //init for a source
  37   *  $translated = $formatter->format($string);
  38   *
  39   *  $choice = new sfChoiceFormat();
  40   *  echo $choice->format($translated, 0); //shows "are no files"
  41   * </code>
  42   *
  43   * The message/string choices are separated by the pipe "|" followed
  44   * by a set notation of the form
  45   *  # <t>[1,2]</t> -- accepts values between 1 and 2, inclusive.
  46   *  # <t>(1,2)</t> -- accepts values between 1 and 2, excluding 1 and 2.
  47   *  # <t>{1,2,3,4}</t> -- only values defined in the set are accepted.
  48   *  # <t>[-Inf,0)</t> -- accepts value greater or equal to negative infinity 
  49   *                       and strictly less than 0
  50   * Any non-empty combinations of the delimiters of square and round brackets
  51   * are acceptable.
  52   *
  53   * @author Xiang Wei Zhuo <weizhuo[at]gmail[dot]com>
  54   * @version v1.0, last update on Fri Dec 24 20:46:16 EST 2004
  55   * @package System.I18N.core
  56   */
  57  class sfChoiceFormat
  58  {
  59    /**
  60     * The pattern to validate a set notation
  61     *
  62     * @var string
  63     */
  64    protected $validate = '/[\(\[\{]|[-Inf\d]+|,|[\+Inf\d]+|[\)\]\}]/ms';
  65  
  66    /**
  67     * The pattern to parse the formatting string.
  68     *
  69     * @var string 
  70     */
  71    protected $parse = '/\s?\|?([\(\[\{]([-Inf\d]+,?[\+Inf\d]*)+[\)\]\}])\s?/';
  72  
  73    /**
  74     * The value for positive infinity.
  75     *
  76     * @var float 
  77     */
  78    protected $inf;
  79  
  80    /**
  81     * Constructor.
  82     */
  83    public function __construct()
  84    {
  85      $this->inf = -log(0);
  86    }
  87  
  88    /**
  89     * Determine if the given number belongs to a given set
  90     *
  91     * @param  float the number to test.
  92     * @param  string the set, in set notation.
  93     * @return boolean true if number is in the set, false otherwise.
  94     */
  95    public function isValid($number, $set)
  96    {
  97      $n = preg_match_all($this->validate, $set, $matches, PREG_SET_ORDER);
  98  
  99      if ($n < 3)
 100      {
 101        $error = 'Invalid set "%s"';
 102        $error = sprintf($error, $set);
 103        throw new sfException($error);
 104      }
 105  
 106      $leftBracket = $matches[0][0];
 107      $rightBracket = $matches[$n - 1][0];
 108  
 109      $i = 0;
 110      $elements = array();
 111  
 112      foreach ($matches as $match)
 113      {
 114        $string = $match[0];
 115        if ($i != 0 && $i != $n - 1 && $string !== ',')
 116        {
 117          if ($string == '-Inf')
 118          {
 119            $elements[] = -1 * $this->inf;
 120          }
 121          else if ($string == '+Inf' || $string == 'Inf')
 122          {
 123            $elements[] = $this->inf;
 124          }
 125          else
 126          {
 127            $elements[] = floatval($string);
 128          }
 129        }
 130        $i++;
 131      }
 132      $total = count($elements);
 133      $number = floatval($number);
 134  
 135      if ($leftBracket == '{' && $rightBracket == '}')
 136      {
 137        return in_array($number, $elements);
 138      }
 139  
 140      $left = false;
 141      if ($leftBracket == '[')
 142      {
 143        $left = $number >= $elements[0];
 144      }
 145      else if ($leftBracket == '(')
 146      {
 147        $left = $number > $elements[0];
 148      }
 149  
 150      $right = false;
 151      if ($rightBracket==']')
 152      {
 153        $right = $number <= $elements[$total - 1];
 154      }
 155      else if ($rightBracket == ')')
 156      {
 157        $right = $number < $elements[$total - 1];
 158      }
 159  
 160      if ($left && $right)
 161      {
 162        return true;
 163      }
 164  
 165      return false;
 166    }
 167  
 168    /**
 169     * Parse a choice string and get a list of sets and a list of strings corresponding to the sets.
 170     *
 171     * @param  string the string containing the choices
 172     * @return array array($sets, $strings)
 173     */
 174    public function parse($string)
 175    {
 176      $n = preg_match_all($this->parse, $string, $matches, PREG_OFFSET_CAPTURE);
 177      $sets = array();
 178      foreach ($matches[1] as $match)
 179      {
 180        $sets[] = $match[0];
 181      }
 182  
 183      $offset = $matches[0];
 184      $strings = array();
 185      for ($i = 0; $i < $n; $i++)
 186      {
 187        $len = strlen($offset[$i][0]);
 188        $begin = $i == 0 ? $len : $offset[$i][1] + $len;
 189        $end = $i == $n - 1 ? strlen($string) : $offset[$i + 1][1];
 190        $strings[] = substr($string, $begin, $end - $begin);
 191      }
 192  
 193      return array($sets, $strings);
 194    }
 195  
 196    /**
 197     * For the choice string, and a number, find and return the string that satisfied the set within the choices.
 198     *
 199     * @param  string the choices string.
 200     * @param  float the number to test.
 201     * @return string the choosen string.
 202     */
 203    public function format($string, $number)
 204    {
 205      list($sets, $strings) = $this->parse($string);
 206      $total = count($sets);
 207      for ($i = 0; $i < $total; $i++)
 208      {
 209        if ($this->isValid($number, $sets[$i]))
 210        {
 211          return $strings[$i];
 212        }
 213      }
 214  
 215      return false;
 216    }
 217  }