Blacklist String Validator Class

Check string for forbidden stuff. The constructur needs one single string argument, that contains the URI to the blacklist.txt file. This list contains one word per line of words that must not occur in the string to validate.


validate("blabla")) echo "ok";
      else echo "failed";

   */

   class CheckContent
   {
      public $blacklistFN; // The textfile with the list of prohibited expressions
      public $content="";  // The content to check - A single string
      private $blacklistA=array();
      private $isValid=TRUE;

      // constructor
      public function CheckContent($blacklist)
      {
	 $this->isValid=TRUE;
	 $this->blacklistFN=$blacklist;
	 $this->content="EMPTY";
      }

      // Main Method
      public function validate($content)
      {
	 $this->content=$content;
	 if(!$this->readFile()) return FALSE;

	 foreach ($this->blacklistA as $a)
	 {
	    if(preg_match('/'.$a.'/i',$content)) $this->isValid=FALSE;
	 }
	 return $this->isValid;
      }

      // Read File
      private function readFile()
      {
	 $blacklistTemp=array();
	 $blacklistS=FALSE;
	 $blacklistS=file_get_contents($this->blacklistFN);
	 if (!$blacklistS) 
	  {
	     echo "*** ERROR from CheckContent:: - Could not read blacklist file: ".$this->blacklistFN;
	     return FALSE;
	  }
	 $blacklistTemp=explode("\n",$blacklistS);
	 // Clean array
	 $this->blacklistA=array();
	 // Only lines that contain letters or digits
	 foreach ($blacklistTemp as $a) if( ereg("[a-zA-Z0-9]",$a) ) array_push($this->blacklistA,trim($a));
	 sort($this->blacklistA); // Cosmetic ;-)
	 return TRUE;
      }
   }