class GuestBook {
protected $file;
protected $reviews = [];

public function __construct ($file) {
   $this->file = fopen ( $file, 'r' );
   while ( !feof($this->file) ) {
   $line = fgets($this->file, 1024);
   $this->reviews[] = $line;
 }
}

public function getData() {
   return $this->reviews;
}

public function append($text) {
   $this->reviews[] = $text;
}

public function save() {
   foreach ($this->reviews as $review) {
   fwrite ($this->file, $review);
   }
   }

}