www.aleph1.co.uk Git - yaffs-website/blob - vendor/caxy/php-htmldiff/lib/Caxy/HtmlDiff/Strategy/ListItemMatchStrategy.php

   1 <?php
   2
   3 namespace Caxy\HtmlDiff\Strategy;
   4
   5 use Caxy\HtmlDiff\Preprocessor;
   6
   7 class ListItemMatchStrategy implements MatchStrategyInterface
   8 {
   9     /**
  10      * @var int
  11      */
  12     protected $similarityThreshold;
  13
  14     /**
  15      * @var float
  16      */
  17     protected $lengthRatioThreshold;
  18
  19     /**
  20      * @var float
  21      */
  22     protected $commonTextRatioThreshold;
  23
  24     /**
  25      * ListItemMatchStrategy constructor.
  26      *
  27      * @param int   $similarityThreshold
  28      * @param float $lengthRatioThreshold
  29      * @param float $commonTextRatioThreshold
  30      */
  31     public function __construct($similarityThreshold = 80, $lengthRatioThreshold = 0.1, $commonTextRatioThreshold = 0.6)
  32     {
  33         $this->similarityThreshold = $similarityThreshold;
  34         $this->lengthRatioThreshold = $lengthRatioThreshold;
  35         $this->commonTextRatioThreshold = $commonTextRatioThreshold;
  36     }
  37
  38     /**
  39      * @param string $a
  40      * @param string $b
  41      *
  42      * @return bool
  43      */
  44     public function isMatch($a, $b)
  45     {
  46         $percentage = null;
  47
  48         // Strip tags and check similarity
  49         $aStripped = strip_tags($a);
  50         $bStripped = strip_tags($b);
  51         similar_text($aStripped, $bStripped, $percentage);
  52
  53         if ($percentage >= $this->similarityThreshold) {
  54             return true;
  55         }
  56
  57         // Check w/o stripped tags
  58         similar_text($a, $b, $percentage);
  59         if ($percentage >= $this->similarityThreshold) {
  60             return true;
  61         }
  62
  63         // Check common prefix/ suffix length
  64         $aCleaned = trim($aStripped);
  65         $bCleaned = trim($bStripped);
  66         if (mb_strlen($aCleaned) === 0 || mb_strlen($bCleaned) === 0) {
  67             $aCleaned = $a;
  68             $bCleaned = $b;
  69         }
  70         if (mb_strlen($aCleaned) === 0 || mb_strlen($bCleaned) === 0) {
  71             return false;
  72         }
  73         $prefixIndex = Preprocessor::diffCommonPrefix($aCleaned, $bCleaned);
  74         $suffixIndex = Preprocessor::diffCommonSuffix($aCleaned, $bCleaned);
  75
  76         // Use shorter string, and see how much of it is leftover
  77         $len = min(mb_strlen($aCleaned), mb_strlen($bCleaned));
  78         $remaining = $len - ($prefixIndex + $suffixIndex);
  79         $strLengthPercent = $len / max(mb_strlen($a), mb_strlen($b));
  80
  81         if ($remaining === 0 && $strLengthPercent > $this->lengthRatioThreshold) {
  82             return true;
  83         }
  84
  85         $percentCommon = ($prefixIndex + $suffixIndex) / $len;
  86
  87         if ($strLengthPercent > 0.1 && $percentCommon > $this->commonTextRatioThreshold) {
  88             return true;
  89         }
  90
  91         return false;
  92     }
  93 }