library/HTMLPurifier/Length.php

   1 <?php
   2
   3 /**
   4  * Represents a measurable length, with a string numeric magnitude
   5  * and a unit.
   6  */
   7 class HTMLPurifier_Length
   8 {
   9
  10     /**
  11      * String numeric magnitude.
  12      */
  13     public $n;
  14
  15     /**
  16      * String unit. False is permitted if $n = 0.
  17      */
  18     public $unit;
  19
  20     /**
  21      * Lookup array of units recognized by CSS 2.1
  22      */
  23     protected static $allowedUnits = array(
  24         'em' => true, 'ex' => true, 'px' => true, 'in' => true,
  25         'cm' => true, 'mm' => true, 'pt' => true, 'pc' => true
  26     );
  27
  28     /**
  29      * @param number $n Magnitude
  30      * @param string $u Unit
  31      */
  32     public function __construct($n = '0', $u = false) {
  33         $this->n = $n;
  34         $this->unit = $u;
  35     }
  36
  37     /**
  38      * @param string $s Unit string, like '2em' or '3.4in'
  39      * @warning Does not perform validation.
  40      */
  41     static public function make($s) {
  42         $n_length = strspn($s, '1234567890.+-');
  43         $n = substr($s, 0, $n_length);
  44         $unit = substr($s, $n_length);
  45         if ($unit === '') $unit = false;
  46         return new HTMLPurifier_Length($n, $unit);
  47     }
  48
  49     /**
  50      * Validates the number and unit.
  51      * @param bool $non_negative Whether or not to disable negative values.
  52      * @note Maybe should be put in another class.
  53      */
  54     public function validate($non_negative = false, $config, $context) {
  55         // Special case:
  56         if ($this->n === '0' && $this->unit === false) return true;
  57         if (!ctype_lower($this->unit)) $this->unit = strtolower($this->unit);
  58         if (!isset(HTMLPurifier_Length::$allowedUnits[$this->unit])) return false;
  59         $def = new HTMLPurifier_AttrDef_CSS_Number($non_negative);
  60         $result = $def->validate($this->n, $config, $context);
  61         if ($result === false) return false;
  62         $this->n = $result;
  63         return true;
  64     }
  65
  66     /**
  67      * Returns string representation of number.
  68      */
  69     public function toString() {
  70         return $this->n . $this->unit;
  71     }
  72
  73 }