lib/php-css-parser/Property/Selector.php

   1 <?php
   2
   3 namespace Sabberworm\CSS\Property;
   4
   5 /**
   6  * Class representing a single CSS selector. Selectors have to be split by the comma prior to being passed into this
   7  * class.
   8  */
   9 class Selector
  10 {
  11     /**
  12      * regexp for specificity calculations
  13      *
  14      * @var string
  15      */
  16     const NON_ID_ATTRIBUTES_AND_PSEUDO_CLASSES_RX = '/
  17         (\.[\w]+)                   # classes
  18         |
  19         \[(\w+)                     # attributes
  20         |
  21         (\:(                        # pseudo classes
  22             link|visited|active
  23             |hover|focus
  24             |lang
  25             |target
  26             |enabled|disabled|checked|indeterminate
  27             |root
  28             |nth-child|nth-last-child|nth-of-type|nth-last-of-type
  29             |first-child|last-child|first-of-type|last-of-type
  30             |only-child|only-of-type
  31             |empty|contains
  32         ))
  33         /ix';
  34
  35     /**
  36      * regexp for specificity calculations
  37      *
  38      * @var string
  39      */
  40     const ELEMENTS_AND_PSEUDO_ELEMENTS_RX = '/
  41         ((^|[\s\+\>\~]+)[\w]+   # elements
  42         |
  43         \:{1,2}(                # pseudo-elements
  44             after|before|first-letter|first-line|selection
  45         ))
  46         /ix';
  47
  48     /**
  49      * regexp for specificity calculations
  50      *
  51      * @var string
  52      */
  53     const SELECTOR_VALIDATION_RX = '/
  54         ^(
  55             (?:
  56                 [a-zA-Z0-9\x{00A0}-\x{FFFF}_^$|*="\'~\[\]()\-\s\.:#+>]* # any sequence of valid unescaped characters
  57                 (?:\\\\.)?                                              # a single escaped character
  58                 (?:([\'"]).*?(?<!\\\\)\2)?                              # a quoted text like [id="example"]
  59             )*
  60         )$
  61         /ux';
  62
  63     /**
  64      * @var string
  65      */
  66     private $sSelector;
  67
  68     /**
  69      * @var int|null
  70      */
  71     private $iSpecificity;
  72
  73     /**
  74      * @param string $sSelector
  75      *
  76      * @return bool
  77      */
  78     public static function isValid($sSelector)
  79     {
  80         return preg_match(static::SELECTOR_VALIDATION_RX, $sSelector);
  81     }
  82
  83     /**
  84      * @param string $sSelector
  85      * @param bool $bCalculateSpecificity
  86      */
  87     public function __construct($sSelector, $bCalculateSpecificity = false)
  88     {
  89         $this->setSelector($sSelector);
  90         if ($bCalculateSpecificity) {
  91             $this->getSpecificity();
  92         }
  93     }
  94
  95     /**
  96      * @return string
  97      */
  98     public function getSelector()
  99     {
 100         return $this->sSelector;
 101     }
 102
 103     /**
 104      * @param string $sSelector
 105      *
 106      * @return void
 107      */
 108     public function setSelector($sSelector)
 109     {
 110         $this->sSelector = trim($sSelector);
 111         $this->iSpecificity = null;
 112     }
 113
 114     /**
 115      * @return string
 116      */
 117     public function __toString()
 118     {
 119         return $this->getSelector();
 120     }
 121
 122     /**
 123      * @return int
 124      */
 125     public function getSpecificity()
 126     {
 127         if ($this->iSpecificity === null) {
 128             $a = 0;
 129             /// @todo should exclude \# as well as "#"
 130             $aMatches = null;
 131             $b = substr_count($this->sSelector, '#');
 132             $c = preg_match_all(self::NON_ID_ATTRIBUTES_AND_PSEUDO_CLASSES_RX, $this->sSelector, $aMatches);
 133             $d = preg_match_all(self::ELEMENTS_AND_PSEUDO_ELEMENTS_RX, $this->sSelector, $aMatches);
 134             $this->iSpecificity = ($a * 1000) + ($b * 100) + ($c * 10) + $d;
 135         }
 136         return $this->iSpecificity;
 137     }
 138 }