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   1  <?php
   2  
   3  /**
   4  * @package   s9e\TextFormatter
   5  * @copyright Copyright (c) 2010-2022 The s9e authors
   6  * @license   http://www.opensource.org/licenses/mit-license.php The MIT License
   7  */
   8  namespace s9e\TextFormatter\Plugins\Censor;
   9  
  10  class Helper
  11  {
  12      /**
  13      * @var string Regexp matching whitelisted words
  14      */
  15      public $allowed;
  16  
  17      /**
  18      * @var string Name of attribute used for the replacement
  19      */
  20      public $attrName = 'with';
  21  
  22      /**
  23      * @var string Default string used to replace censored words
  24      */
  25      public $defaultReplacement = '****';
  26  
  27      /**
  28      * @var string Regexp matching blacklisted words in plain text
  29      */
  30      public $regexp = '/(?!)/';
  31  
  32      /**
  33      * @var string Regexp matching blacklisted words in HTML
  34      */
  35      public $regexpHtml = '/(?!)/';
  36  
  37      /**
  38      * @var array Array of [regexp => replacement]
  39      */
  40      public $replacements = [];
  41  
  42      /**
  43      * @var string Name of the tag used to mark censored words
  44      */
  45      public $tagName = 'CENSOR';
  46  
  47      /**
  48      * Constructor
  49      *
  50      * @param  array $config Helper's config
  51      */
  52  	public function __construct(array $config)
  53      {
  54          foreach ($config as $k => $v)
  55          {
  56              $this->$k = $v;
  57          }
  58      }
  59  
  60      /**
  61      * Censor text nodes inside of HTML code
  62      *
  63      * NOTE: will only recognize attributes that are enclosed in double quotes
  64      *
  65      * @param  string $html             Original HTML
  66      * @param  bool   $censorAttributes Whether to censor the content of attributes
  67      * @return string                   Censored HTML
  68      */
  69  	public function censorHtml($html, $censorAttributes = false)
  70      {
  71          $attributesExpr = '';
  72          if ($censorAttributes)
  73          {
  74              $attributesExpr = '|[^<">]*+(?="(?> [-\\w]+="[^"]*+")*+\\/?>)';
  75          }
  76  
  77          // Modify the original regexp so that it only matches text nodes and optionally attribute
  78          // values
  79          $delim  = $this->regexpHtml[0];
  80          $pos    = strrpos($this->regexpHtml, $delim);
  81          $regexp = $delim
  82                  . '(?<!&|&#)'
  83                  . substr($this->regexpHtml, 1, $pos - 1)
  84                  . '(?=[^<>]*+(?=<|$)' . $attributesExpr . ')'
  85                  . substr($this->regexpHtml, $pos);
  86  
  87          return preg_replace_callback(
  88              $regexp,
  89              function ($m)
  90              {
  91                  return htmlspecialchars($this->getReplacement(html_entity_decode($m[0], ENT_QUOTES, 'UTF-8')), ENT_QUOTES);
  92              },
  93              $html
  94          );
  95      }
  96  
  97      /**
  98      * Censor given plain text
  99      *
 100      * @param  string $text Original text
 101      * @return string       Censored text
 102      */
 103  	public function censorText($text)
 104      {
 105          return preg_replace_callback(
 106              $this->regexp,
 107              function ($m)
 108              {
 109                  return $this->getReplacement($m[0]);
 110              },
 111              $text
 112          );
 113      }
 114  
 115      /**
 116      * Test whether given word is censored
 117      *
 118      * @param  string $word
 119      * @return bool
 120      */
 121  	public function isCensored($word)
 122      {
 123          return (preg_match($this->regexp, $word) && !$this->isAllowed($word));
 124      }
 125  
 126      /**
 127      * Get the replacement for given word
 128      *
 129      * @param  string $word Original word
 130      * @return string       Replacement if the word is censored, or the original word otherwise
 131      */
 132  	protected function getReplacement($word)
 133      {
 134          if ($this->isAllowed($word))
 135          {
 136              return $word;
 137          }
 138  
 139          foreach ($this->replacements as list($regexp, $replacement))
 140          {
 141              if (preg_match($regexp, $word))
 142              {
 143                  return $replacement;
 144              }
 145          }
 146  
 147          return $this->defaultReplacement;
 148      }
 149  
 150      /**
 151      * Test whether given word is allowed (whitelisted)
 152      *
 153      * @param  string $word
 154      * @return bool
 155      */
 156  	protected function isAllowed($word)
 157      {
 158          return (isset($this->allowed) && preg_match($this->allowed, $word));
 159      }
 160  }